Several months ago I had a high efficiency Trane XV90 natural gas
furnace and heat pump installed. Since the weather has recently been
cold enough for the gas furnace to provide heat, I have been
experiencing severe radio interference. The interference wipes out AM
broadcast reception throughout my house. I also see snow on a TV
connected to an external antenna.

The radio noise occurs as soon as the draft inducer motor starts up;
the pitch of the interference is related to the motor speed. The draft
inducer motor is a dc motor driven by a PWM controller on the main
circuit board. It is well known that PWM systems generate strong
harmonics throughout the radio spectrum, resulting in radio
interference. However, properly designed PWM systems include filtering
and shielding to suppress the radio frequency currents from the wiring.

I contacted my installer, who is totally unfamiliar with the problem.
The electrician who was sent to my house to investigate the problem
also doesn't understand what's going on. I had to explain the
difference between an RF ground and dc or house ground to him.
Although everything appears to be well grounded from a dc perspective,
I suspect that portions of the system are radiating RF energy.

Several days ago I emailed Trane about the problem, but haven't
received any response.

Although there has been past discussion in this group about radio/TV
interference emanating from Trane high efficiency gas furnaces, I
haven't seen any definitive fix. Does anyone know if Trane has a fix
for this problem. Do they have a shielded cable and or rf filter kit
to suppress this noise? Since my system is under warranty, I won't
attempt any modiifcations to the system.

Has anyone experienced this problem?

Thanks.

modelman wrote:
Several months ago I had a high efficiency Trane XV90 natural gas
furnace and heat pump installed. Since the weather has recently been
cold enough for the gas furnace to provide heat, I have been
experiencing severe radio interference. The interference wipes out AM
broadcast reception throughout my house. I also see snow on a TV
connected to an external antenna.

The radio noise occurs as soon as the draft inducer motor starts up;
the pitch of the interference is related to the motor speed. The draft
inducer motor is a dc motor driven by a PWM controller on the main
circuit board. It is well known that PWM systems generate strong
harmonics throughout the radio spectrum, resulting in radio
interference. However, properly designed PWM systems include filtering
and shielding to suppress the radio frequency currents from the wiring.

I contacted my installer, who is totally unfamiliar with the problem.
The electrician who was sent to my house to investigate the problem
also doesn't understand what's going on. I had to explain the
difference between an RF ground and dc or house ground to him.
Although everything appears to be well grounded from a dc perspective,
I suspect that portions of the system are radiating RF energy.

Several days ago I emailed Trane about the problem, but haven't
received any response.

Although there has been past discussion in this group about radio/TV
interference emanating from Trane high efficiency gas furnaces, I
haven't seen any definitive fix. Does anyone know if Trane has a fix
for this problem. Do they have a shielded cable and or rf filter kit
to suppress this noise? Since my system is under warranty, I won't
attempt any modiifcations to the system.

Has anyone experienced this problem?

Thanks.

Hi,
First you'll have to find out whether the interference is coming thru
the power line or thru the air. It can be cured but needs some expert
knowledge. Maybe Trane has noise suppressor kit of sort? Better check
with them.
Tony, VE6CGX

i would first try telephoning manufacturer, there appears to be a 5
year warranty.
http://www.trane.com/Residential/Pro...aces/XV90.aspx
see ARRL. ham radio neighbors nearby will help you if it is bothering
them.
example of their problem at:
http://www.arrl.org/tis/info/HTML/pl...-08-28-06.html
good luck.

modelman wrote:
Several months ago I had a high efficiency Trane XV90 natural gas
furnace and heat pump installed. Since the weather has recently been
cold enough for the gas furnace to provide heat, I have been
experiencing severe radio interference. The interference wipes out AM
broadcast reception throughout my house. I also see snow on a TV
connected to an external antenna.

The radio noise occurs as soon as the draft inducer motor starts up;
the pitch of the interference is related to the motor speed. The draft
inducer motor is a dc motor driven by a PWM controller on the main
circuit board. It is well known that PWM systems generate strong
harmonics throughout the radio spectrum, resulting in radio
interference. However, properly designed PWM systems include filtering
and shielding to suppress the radio frequency currents from the wiring.

I contacted my installer, who is totally unfamiliar with the problem.
The electrician who was sent to my house to investigate the problem
also doesn't understand what's going on. I had to explain the
difference between an RF ground and dc or house ground to him.
Although everything appears to be well grounded from a dc perspective,
I suspect that portions of the system are radiating RF energy.

Several days ago I emailed Trane about the problem, but haven't
received any response.

Although there has been past discussion in this group about radio/TV
interference emanating from Trane high efficiency gas furnaces, I
haven't seen any definitive fix. Does anyone know if Trane has a fix
for this problem. Do they have a shielded cable and or rf filter kit
to suppress this noise? Since my system is under warranty, I won't
attempt any modiifcations to the system.

Has anyone experienced this problem?

Thanks.

and see:
http://groups.google.com/group/alt.h...rch+this+group

modelman wrote:
Several months ago I had a high efficiency Trane XV90 natural gas
furnace and heat pump installed. Since the weather has recently been
cold enough for the gas furnace to provide heat, I have been
experiencing severe radio interference. The interference wipes out AM
broadcast reception throughout my house. I also see snow on a TV
connected to an external antenna.

The radio noise occurs as soon as the draft inducer motor starts up;
the pitch of the interference is related to the motor speed. The draft
inducer motor is a dc motor driven by a PWM controller on the main
circuit board. It is well known that PWM systems generate strong
harmonics throughout the radio spectrum, resulting in radio
interference. However, properly designed PWM systems include filtering
and shielding to suppress the radio frequency currents from the wiring.

I contacted my installer, who is totally unfamiliar with the problem.
The electrician who was sent to my house to investigate the problem
also doesn't understand what's going on. I had to explain the
difference between an RF ground and dc or house ground to him.
Although everything appears to be well grounded from a dc perspective,
I suspect that portions of the system are radiating RF energy.

Several days ago I emailed Trane about the problem, but haven't
received any response.

Although there has been past discussion in this group about radio/TV
interference emanating from Trane high efficiency gas furnaces, I
haven't seen any definitive fix. Does anyone know if Trane has a fix
for this problem. Do they have a shielded cable and or rf filter kit
to suppress this noise? Since my system is under warranty, I won't
attempt any modiifcations to the system.

Has anyone experienced this problem?

Thanks.

Tony,

The interference is being radiated, since I can hear it loud and clear
on a "walkman" outside of my house. I haven't yet determined which
wiring (power line to the furnace, thermostat cables, etc) is doing
most of the radiating. When I "sniff" the wires with my walkman radio,
everything seems to be hot with the rf interference. There is no
significant change in intensity with split core ferrites (type 31
ferrite) on the thermostat cable. I haven't yet tried an EMI filter in
series with the ac line to the furnace. That would require some work
on my part, and I want to give Trane a chance to solve this problem.

Yesterday I questioned the electrician about why the furnace ground is
connected to the gas pipe; I didn't get a logical answer. He said that
is the way it's done on all installations. I pointed out that the gas
pipe is bonded to the electrical ground of the house and water pipes at
its far end about 25 feet from the furnace, providing a dc ground but
not an rf ground. I suspect that the gas pipe may be acting as an
antenna. However, there was no change in interference when the ground
is lifted from the gas pipe. A short ground connection to a ground rod
may provide a better rf ground for the furnace.

The outfit who installed my furnace promised to contact Trane today. I
hope to know more shortly about what solution Trane proposes.

Thanks.

Jack, K1VT


Tony Hwang wrote:
modelman wrote:
Several months ago I had a high efficiency Trane XV90 natural gas
furnace and heat pump installed. Since the weather has recently been
cold enough for the gas furnace to provide heat, I have been
experiencing severe radio interference. The interference wipes out AM
broadcast reception throughout my house. I also see snow on a TV
connected to an external antenna.

The radio noise occurs as soon as the draft inducer motor starts up;
the pitch of the interference is related to the motor speed. The draft
inducer motor is a dc motor driven by a PWM controller on the main
circuit board. It is well known that PWM systems generate strong
harmonics throughout the radio spectrum, resulting in radio
interference. However, properly designed PWM systems include filtering
and shielding to suppress the radio frequency currents from the wiring.

I contacted my installer, who is totally unfamiliar with the problem.
The electrician who was sent to my house to investigate the problem
also doesn't understand what's going on. I had to explain the
difference between an RF ground and dc or house ground to him.
Although everything appears to be well grounded from a dc perspective,
I suspect that portions of the system are radiating RF energy.

Several days ago I emailed Trane about the problem, but haven't
received any response.

Although there has been past discussion in this group about radio/TV
interference emanating from Trane high efficiency gas furnaces, I
haven't seen any definitive fix. Does anyone know if Trane has a fix
for this problem. Do they have a shielded cable and or rf filter kit
to suppress this noise? Since my system is under warranty, I won't
attempt any modiifcations to the system.

Has anyone experienced this problem?

Thanks.

Hi,
First you'll have to find out whether the interference is coming thru
the power line or thru the air. It can be cured but needs some expert
knowledge. Maybe Trane has noise suppressor kit of sort? Better check
with them.
Tony, VE6CGX

"modelman" wrote in message
oups.com...
Several months ago I had a high efficiency Trane XV90 natural gas
furnace and heat pump installed. Since the weather has recently been
cold enough for the gas furnace to provide heat, I have been
experiencing severe radio interference. The interference wipes out AM
broadcast reception throughout my house. I also see snow on a TV
connected to an external antenna.

The radio noise occurs as soon as the draft inducer motor starts up;
the pitch of the interference is related to the motor speed. The draft
inducer motor is a dc motor driven by a PWM controller on the main
circuit board. It is well known that PWM systems generate strong
harmonics throughout the radio spectrum, resulting in radio
interference. However, properly designed PWM systems include filtering
and shielding to suppress the radio frequency currents from the wiring.

I contacted my installer, who is totally unfamiliar with the problem.
The electrician who was sent to my house to investigate the problem
also doesn't understand what's going on. I had to explain the
difference between an RF ground and dc or house ground to him.
Although everything appears to be well grounded from a dc perspective,
I suspect that portions of the system are radiating RF energy.

Several days ago I emailed Trane about the problem, but haven't
received any response.

Although there has been past discussion in this group about radio/TV
interference emanating from Trane high efficiency gas furnaces, I
haven't seen any definitive fix. Does anyone know if Trane has a fix
for this problem. Do they have a shielded cable and or rf filter kit
to suppress this noise? Since my system is under warranty, I won't
attempt any modiifcations to the system.

Has anyone experienced this problem?

Thanks.


Here's one guy that had the exact same problem. I was a bit luckier that
you in that it didn't bother my AM radio signal but it did screw up my
kitchen TV picture--rabbit ears. It's coming from the inducer motor as you
surmised. The installer was very cooperative and tried to fix it based on
input from Trane. Changed out the cable to the motor with one that was
supposed to provide better shielding and when that didn't work changed the
control board---both without any success. Prior to and after component
replacements I tried grounding everything that I could, again with no
success. Got the local Trane Rep on the phone; he made promises but never
followed through with a solution. Had a new Trane for about a year that got
into a problem resulting in it being replaced under warranty rather than
repaired--it was the replacement furnace that had the RF noise problem.
Found out that Trane went to a "new design" inducer motor. I tried to get
the Trane Rep to replace the motor with the same design that was on my first
furnace. No luck there, was just ignored and yessed to death. If Trane acts
dumb about the RF noise it's all show-because mine happened about a year
ago. My guess is that you're stuck with the problem. I finally made mine
going away by putting in a cable line to the TV.
My suggestion in your tussle with Trane or the installer is to go find an
inducer motor from an earlier vintage furnace. Even if it has to be
cannibalized off an older (2yrs or so) furnace.
MLD

Looking back, I now recall that replacing the inducer motor wiring harness
with one that had better shielding did make a significant improvement
although it didn't completely resolve the noise problem.
MLD


"MLD" wrote in message news:q0J4h.5540$qG.1024@trndny02...

"modelman" wrote in message
oups.com...
Several months ago I had a high efficiency Trane XV90 natural gas
furnace and heat pump installed. Since the weather has recently been
cold enough for the gas furnace to provide heat, I have been
experiencing severe radio interference. The interference wipes out AM
broadcast reception throughout my house. I also see snow on a TV
connected to an external antenna.

The radio noise occurs as soon as the draft inducer motor starts up;
the pitch of the interference is related to the motor speed. The draft
inducer motor is a dc motor driven by a PWM controller on the main
circuit board. It is well known that PWM systems generate strong
harmonics throughout the radio spectrum, resulting in radio
interference. However, properly designed PWM systems include filtering
and shielding to suppress the radio frequency currents from the wiring.

I contacted my installer, who is totally unfamiliar with the problem.
The electrician who was sent to my house to investigate the problem
also doesn't understand what's going on. I had to explain the
difference between an RF ground and dc or house ground to him.
Although everything appears to be well grounded from a dc perspective,
I suspect that portions of the system are radiating RF energy.

Several days ago I emailed Trane about the problem, but haven't
received any response.

Although there has been past discussion in this group about radio/TV
interference emanating from Trane high efficiency gas furnaces, I
haven't seen any definitive fix. Does anyone know if Trane has a fix
for this problem. Do they have a shielded cable and or rf filter kit
to suppress this noise? Since my system is under warranty, I won't
attempt any modiifcations to the system.

Has anyone experienced this problem?

Thanks.


Here's one guy that had the exact same problem. I was a bit luckier that
you in that it didn't bother my AM radio signal but it did screw up my
kitchen TV picture--rabbit ears. It's coming from the inducer motor as
you
surmised. The installer was very cooperative and tried to fix it based on
input from Trane. Changed out the cable to the motor with one that was
supposed to provide better shielding and when that didn't work changed the
control board---both without any success. Prior to and after component
replacements I tried grounding everything that I could, again with no
success. Got the local Trane Rep on the phone; he made promises but never
followed through with a solution. Had a new Trane for about a year that
got
into a problem resulting in it being replaced under warranty rather than
repaired--it was the replacement furnace that had the RF noise problem.
Found out that Trane went to a "new design" inducer motor. I tried to get
the Trane Rep to replace the motor with the same design that was on my
first
furnace. No luck there, was just ignored and yessed to death. If Trane
acts
dumb about the RF noise it's all show-because mine happened about a year
ago. My guess is that you're stuck with the problem. I finally made mine
going away by putting in a cable line to the TV.
My suggestion in your tussle with Trane or the installer is to go find an
inducer motor from an earlier vintage furnace. Even if it has to be
cannibalized off an older (2yrs or so) furnace.
MLD

This comment opens up the possibility that wrapping the existing harness
with a braided wrap as a helix and then bonding the outer braid to a good
earth ground may help the radiated electromagnetic interference (EMI). The
conducted noise will still need to be filtered / trapped before the wiring
enters / exists the furnace. Given that this EMI goes from the AM band
(approx 1 MHz frequency all the way up to VHF or UHF television frequencies,
however, the likelihood of being able to devise a good wideband filter which
substantially reduces the conducted EMI is remote without a lot of expense.
If the motor itself is truly the principal noise source, then getting some
noise suppression right at the motor offers the best solution, either with
shielding, series inductors (chokes), shunt capacitors, or all of the above.
The motor brushes and commutating connections may be creating a lot of
arcing, and a new motor may help if it is constructed differently (from a
different vendor).

Smarty


"MLD" wrote in message news:d6J4h.3603$Ue.2593@trndny03...
Looking back, I now recall that replacing the inducer motor wiring harness
with one that had better shielding did make a significant improvement
although it didn't completely resolve the noise problem.
MLD


"MLD" wrote in message
news:q0J4h.5540$qG.1024@trndny02...

"modelman" wrote in message
oups.com...
Several months ago I had a high efficiency Trane XV90 natural gas
furnace and heat pump installed. Since the weather has recently been
cold enough for the gas furnace to provide heat, I have been
experiencing severe radio interference. The interference wipes out AM
broadcast reception throughout my house. I also see snow on a TV
connected to an external antenna.

The radio noise occurs as soon as the draft inducer motor starts up;
the pitch of the interference is related to the motor speed. The draft
inducer motor is a dc motor driven by a PWM controller on the main
circuit board. It is well known that PWM systems generate strong
harmonics throughout the radio spectrum, resulting in radio
interference. However, properly designed PWM systems include filtering
and shielding to suppress the radio frequency currents from the wiring.

I contacted my installer, who is totally unfamiliar with the problem.
The electrician who was sent to my house to investigate the problem
also doesn't understand what's going on. I had to explain the
difference between an RF ground and dc or house ground to him.
Although everything appears to be well grounded from a dc perspective,
I suspect that portions of the system are radiating RF energy.

Several days ago I emailed Trane about the problem, but haven't
received any response.

Although there has been past discussion in this group about radio/TV
interference emanating from Trane high efficiency gas furnaces, I
haven't seen any definitive fix. Does anyone know if Trane has a fix
for this problem. Do they have a shielded cable and or rf filter kit
to suppress this noise? Since my system is under warranty, I won't
attempt any modiifcations to the system.

Has anyone experienced this problem?

Thanks.


Here's one guy that had the exact same problem. I was a bit luckier that
you in that it didn't bother my AM radio signal but it did screw up my
kitchen TV picture--rabbit ears. It's coming from the inducer motor as
you
surmised. The installer was very cooperative and tried to fix it based
on
input from Trane. Changed out the cable to the motor with one that was
supposed to provide better shielding and when that didn't work changed
the
control board---both without any success. Prior to and after component
replacements I tried grounding everything that I could, again with no
success. Got the local Trane Rep on the phone; he made promises but
never
followed through with a solution. Had a new Trane for about a year that
got
into a problem resulting in it being replaced under warranty rather than
repaired--it was the replacement furnace that had the RF noise problem.
Found out that Trane went to a "new design" inducer motor. I tried to get
the Trane Rep to replace the motor with the same design that was on my
first
furnace. No luck there, was just ignored and yessed to death. If Trane
acts
dumb about the RF noise it's all show-because mine happened about a year
ago. My guess is that you're stuck with the problem. I finally made
mine
going away by putting in a cable line to the TV.
My suggestion in your tussle with Trane or the installer is to go find an
inducer motor from an earlier vintage furnace. Even if it has to be
cannibalized off an older (2yrs or so) furnace.
MLD

Just to remake the point---the problem is, without question, the inducer
motor. The "new shielded" harness put in my furnace still had, in my
opinion, a major flaw. The wires at both connector ends was unshielded for
approx 1 inch. So all the wires, at both ends, was exposed to picking up
and/or radiating any RF noise. I shielded, using foil, the exposed wires,
grounded the harness shielding to the furnace, my earth ground, water pipe
and control board grounds. Nothing got rid of the noise problem. You offer
some potential fixes but its apparent that Trane isn't interested in putting
any effort into resolving the issue.
MLD

"Smarty" wrote in message
...
This comment opens up the possibility that wrapping the existing harness
with a braided wrap as a helix and then bonding the outer braid to a good
earth ground may help the radiated electromagnetic interference (EMI). The
conducted noise will still need to be filtered / trapped before the wiring
enters / exists the furnace. Given that this EMI goes from the AM band
(approx 1 MHz frequency all the way up to VHF or UHF television
frequencies,
however, the likelihood of being able to devise a good wideband filter
which
substantially reduces the conducted EMI is remote without a lot of
expense.
If the motor itself is truly the principal noise source, then getting some
noise suppression right at the motor offers the best solution, either with
shielding, series inductors (chokes), shunt capacitors, or all of the
above.
The motor brushes and commutating connections may be creating a lot of
arcing, and a new motor may help if it is constructed differently (from a
different vendor).

Smarty


"MLD" wrote in message
news:d6J4h.3603$Ue.2593@trndny03...
Looking back, I now recall that replacing the inducer motor wiring
harness
with one that had better shielding did make a significant improvement
although it didn't completely resolve the noise problem.
MLD


"MLD" wrote in message
news:q0J4h.5540$qG.1024@trndny02...

"modelman" wrote in message
oups.com...
Several months ago I had a high efficiency Trane XV90 natural gas
furnace and heat pump installed. Since the weather has recently been
cold enough for the gas furnace to provide heat, I have been
experiencing severe radio interference. The interference wipes out
AM
broadcast reception throughout my house. I also see snow on a TV
connected to an external antenna.

The radio noise occurs as soon as the draft inducer motor starts up;
the pitch of the interference is related to the motor speed. The
draft
inducer motor is a dc motor driven by a PWM controller on the main
circuit board. It is well known that PWM systems generate strong
harmonics throughout the radio spectrum, resulting in radio
interference. However, properly designed PWM systems include
filtering
and shielding to suppress the radio frequency currents from the
wiring.

I contacted my installer, who is totally unfamiliar with the problem.
The electrician who was sent to my house to investigate the problem
also doesn't understand what's going on. I had to explain the
difference between an RF ground and dc or house ground to him.
Although everything appears to be well grounded from a dc
perspective,
I suspect that portions of the system are radiating RF energy.

Several days ago I emailed Trane about the problem, but haven't
received any response.

Although there has been past discussion in this group about radio/TV
interference emanating from Trane high efficiency gas furnaces, I
haven't seen any definitive fix. Does anyone know if Trane has a fix
for this problem. Do they have a shielded cable and or rf filter
kit
to suppress this noise? Since my system is under warranty, I won't
attempt any modiifcations to the system.

Has anyone experienced this problem?

Thanks.


Here's one guy that had the exact same problem. I was a bit luckier
that
you in that it didn't bother my AM radio signal but it did screw up my
kitchen TV picture--rabbit ears. It's coming from the inducer motor as
you
surmised. The installer was very cooperative and tried to fix it based
on
input from Trane. Changed out the cable to the motor with one that was
supposed to provide better shielding and when that didn't work changed
the
control board---both without any success. Prior to and after component
replacements I tried grounding everything that I could, again with no
success. Got the local Trane Rep on the phone; he made promises but
never
followed through with a solution. Had a new Trane for about a year
that
got
into a problem resulting in it being replaced under warranty rather
than
repaired--it was the replacement furnace that had the RF noise problem.
Found out that Trane went to a "new design" inducer motor. I tried to
get
the Trane Rep to replace the motor with the same design that was on my
first
furnace. No luck there, was just ignored and yessed to death. If Trane
acts
dumb about the RF noise it's all show-because mine happened about a
year
ago. My guess is that you're stuck with the problem. I finally made
mine
going away by putting in a cable line to the TV.
My suggestion in your tussle with Trane or the installer is to go find
an
inducer motor from an earlier vintage furnace. Even if it has to be
cannibalized off an older (2yrs or so) furnace.
MLD

MLD

Interesting that your problem was with the motor itself and not the PWM
circuitry. My first thought was that the fast switching of the PWM
generates strong high frequency components. I note that the whine
(modulation on the noise) varies varies with the motor speed.

My furnace is only about 4 months old and is also under the 10 year
extended warranty (offered as a promotion), so I don't want to mess
with my own shielding. If Trane doesn't provide a fix, I will continue
experimenting with split core ferrites on various wires. I haven't
tried putting ferrittes on the wiring to the motor.

Since the motor is surrounded by the metal cabinet shielding, the noise
must first be conducted out of the enclosure on wiring, from which it
then radiates.

MLD wrote:
"modelman" wrote in message
oups.com...
Several months ago I had a high efficiency Trane XV90 natural gas
furnace and heat pump installed. Since the weather has recently been
cold enough for the gas furnace to provide heat, I have been
experiencing severe radio interference. The interference wipes out AM
broadcast reception throughout my house. I also see snow on a TV
connected to an external antenna.

The radio noise occurs as soon as the draft inducer motor starts up;
the pitch of the interference is related to the motor speed. The draft
inducer motor is a dc motor driven by a PWM controller on the main
circuit board. It is well known that PWM systems generate strong
harmonics throughout the radio spectrum, resulting in radio
interference. However, properly designed PWM systems include filtering
and shielding to suppress the radio frequency currents from the wiring.

I contacted my installer, who is totally unfamiliar with the problem.
The electrician who was sent to my house to investigate the problem
also doesn't understand what's going on. I had to explain the
difference between an RF ground and dc or house ground to him.
Although everything appears to be well grounded from a dc perspective,
I suspect that portions of the system are radiating RF energy.

Several days ago I emailed Trane about the problem, but haven't
received any response.

Although there has been past discussion in this group about radio/TV
interference emanating from Trane high efficiency gas furnaces, I
haven't seen any definitive fix. Does anyone know if Trane has a fix
for this problem. Do they have a shielded cable and or rf filter kit
to suppress this noise? Since my system is under warranty, I won't
attempt any modiifcations to the system.

Has anyone experienced this problem?

Thanks.


Here's one guy that had the exact same problem. I was a bit luckier that
you in that it didn't bother my AM radio signal but it did screw up my
kitchen TV picture--rabbit ears. It's coming from the inducer motor as you
surmised. The installer was very cooperative and tried to fix it based on
input from Trane. Changed out the cable to the motor with one that was
supposed to provide better shielding and when that didn't work changed the
control board---both without any success. Prior to and after component
replacements I tried grounding everything that I could, again with no
success. Got the local Trane Rep on the phone; he made promises but never
followed through with a solution. Had a new Trane for about a year that got
into a problem resulting in it being replaced under warranty rather than
repaired--it was the replacement furnace that had the RF noise problem.
Found out that Trane went to a "new design" inducer motor. I tried to get
the Trane Rep to replace the motor with the same design that was on my first
furnace. No luck there, was just ignored and yessed to death. If Trane acts
dumb about the RF noise it's all show-because mine happened about a year
ago. My guess is that you're stuck with the problem. I finally made mine
going away by putting in a cable line to the TV.
My suggestion in your tussle with Trane or the installer is to go find an
inducer motor from an earlier vintage furnace. Even if it has to be
cannibalized off an older (2yrs or so) furnace.
MLD

The retrofitted grounded helical shield may be effective if the
windings on the helix are bridged; the shield needs to provide a low
impedance for the noise. Otherwise, the noise current would be forced
to follow, and be impeded by, the windings of the helix, which is
simply an inductor.

If Trane doesn't have a solution within a reasonable amount of time, I
may experiment with such shielding. It would take some very careful
soldering to bridge the windings without damaging the insulation on the
enclosed wires.

I may also try using some very light guage copper sheet (or foil)
folded around the wiring harness and closed with screws and nuts. That
way I wouldn't have to worry about soldering and bridging the turns on
the helix.

Any other ideas?

Smarty wrote:
This comment opens up the possibility that wrapping the existing harness
with a braided wrap as a helix and then bonding the outer braid to a good
earth ground may help the radiated electromagnetic interference (EMI). The
conducted noise will still need to be filtered / trapped before the wiring
enters / exists the furnace. Given that this EMI goes from the AM band
(approx 1 MHz frequency all the way up to VHF or UHF television frequencies,
however, the likelihood of being able to devise a good wideband filter which
substantially reduces the conducted EMI is remote without a lot of expense.
If the motor itself is truly the principal noise source, then getting some
noise suppression right at the motor offers the best solution, either with
shielding, series inductors (chokes), shunt capacitors, or all of the above.
The motor brushes and commutating connections may be creating a lot of
arcing, and a new motor may help if it is constructed differently (from a
different vendor).

Smarty


"MLD" wrote in message news:d6J4h.3603$Ue.2593@trndny03...
Looking back, I now recall that replacing the inducer motor wiring harness
with one that had better shielding did make a significant improvement
although it didn't completely resolve the noise problem.
MLD


"MLD" wrote in message
news:q0J4h.5540$qG.1024@trndny02...

"modelman" wrote in message
oups.com...
Several months ago I had a high efficiency Trane XV90 natural gas
furnace and heat pump installed. Since the weather has recently been
cold enough for the gas furnace to provide heat, I have been
experiencing severe radio interference. The interference wipes out AM
broadcast reception throughout my house. I also see snow on a TV
connected to an external antenna.

The radio noise occurs as soon as the draft inducer motor starts up;
the pitch of the interference is related to the motor speed. The draft
inducer motor is a dc motor driven by a PWM controller on the main
circuit board. It is well known that PWM systems generate strong
harmonics throughout the radio spectrum, resulting in radio
interference. However, properly designed PWM systems include filtering
and shielding to suppress the radio frequency currents from the wiring.

I contacted my installer, who is totally unfamiliar with the problem.
The electrician who was sent to my house to investigate the problem
also doesn't understand what's going on. I had to explain the
difference between an RF ground and dc or house ground to him.
Although everything appears to be well grounded from a dc perspective,
I suspect that portions of the system are radiating RF energy.

Several days ago I emailed Trane about the problem, but haven't
received any response.

Although there has been past discussion in this group about radio/TV
interference emanating from Trane high efficiency gas furnaces, I
haven't seen any definitive fix. Does anyone know if Trane has a fix
for this problem. Do they have a shielded cable and or rf filter kit
to suppress this noise? Since my system is under warranty, I won't
attempt any modiifcations to the system.

Has anyone experienced this problem?

Thanks.


Here's one guy that had the exact same problem. I was a bit luckier that
you in that it didn't bother my AM radio signal but it did screw up my
kitchen TV picture--rabbit ears. It's coming from the inducer motor as
you
surmised. The installer was very cooperative and tried to fix it based
on
input from Trane. Changed out the cable to the motor with one that was
supposed to provide better shielding and when that didn't work changed
the
control board---both without any success. Prior to and after component
replacements I tried grounding everything that I could, again with no
success. Got the local Trane Rep on the phone; he made promises but
never
followed through with a solution. Had a new Trane for about a year that
got
into a problem resulting in it being replaced under warranty rather than
repaired--it was the replacement furnace that had the RF noise problem.
Found out that Trane went to a "new design" inducer motor. I tried to get
the Trane Rep to replace the motor with the same design that was on my
first
furnace. No luck there, was just ignored and yessed to death. If Trane
acts
dumb about the RF noise it's all show-because mine happened about a year
ago. My guess is that you're stuck with the problem. I finally made
mine
going away by putting in a cable line to the TV.
My suggestion in your tussle with Trane or the installer is to go find an
inducer motor from an earlier vintage furnace. Even if it has to be
cannibalized off an older (2yrs or so) furnace.
MLD

modelman wrote:
Several months ago I had a high efficiency Trane XV90 natural gas
furnace and heat pump installed. Since the weather has recently been
cold enough for the gas furnace to provide heat, I have been
experiencing severe radio interference. The interference wipes out AM
broadcast reception throughout my house. I also see snow on a TV
connected to an external antenna.

The radio noise occurs as soon as the draft inducer motor starts up;
the pitch of the interference is related to the motor speed. The draft
inducer motor is a dc motor driven by a PWM controller on the main
circuit board. It is well known that PWM systems generate strong
harmonics throughout the radio spectrum, resulting in radio
interference. However, properly designed PWM systems include filtering
and shielding to suppress the radio frequency currents from the wiring.

I contacted my installer, who is totally unfamiliar with the problem.
The electrician who was sent to my house to investigate the problem
also doesn't understand what's going on. I had to explain the
difference between an RF ground and dc or house ground to him.
Although everything appears to be well grounded from a dc perspective,
I suspect that portions of the system are radiating RF energy.

Several days ago I emailed Trane about the problem, but haven't
received any response.

Although there has been past discussion in this group about radio/TV
interference emanating from Trane high efficiency gas furnaces, I
haven't seen any definitive fix. Does anyone know if Trane has a fix
for this problem. Do they have a shielded cable and or rf filter kit
to suppress this noise? Since my system is under warranty, I won't
attempt any modiifcations to the system.

Has anyone experienced this problem?

Thanks.


Trane should be made to fix this and recall all the units that have
been installed. I can pick this interference up on a 2 meter receiver
in my car for blocks. The FCC should bust them if they don't fix it...

I cross posted this to some of the amateur radio groups.

Mark

Given Trane's attitude and the fact that you have localized the problem to
originate at the induction blower, I would replace the motor leaving the
existing associated parts intact if possible (impeller / squirrel cage /
overtemp thermostat, etc) or replace the entire assembly which includes the
motor and associated parts entirely. Having replaced two of these myself, I
know this is likely to be a $175 item or more. Adding EMI filtering requires
more measurement and experimentation than most people are willing to try,
IMHO, so I am reluctant to suggest designing your own EMI filter by trial
and error. Wrapping some foil around the blower housing (being careful to
avoid shorting out any attached thermostats / safety switches / may help if
the motor itself is radiating (as opposed to conduction out through the
wiring harness).

Smarty


"MLD" wrote in message news:CsO4h.3626$Ue.913@trndny03...
Just to remake the point---the problem is, without question, the inducer
motor. The "new shielded" harness put in my furnace still had, in my
opinion, a major flaw. The wires at both connector ends was unshielded
for
approx 1 inch. So all the wires, at both ends, was exposed to picking up
and/or radiating any RF noise. I shielded, using foil, the exposed wires,
grounded the harness shielding to the furnace, my earth ground, water pipe
and control board grounds. Nothing got rid of the noise problem. You
offer
some potential fixes but its apparent that Trane isn't interested in
putting
any effort into resolving the issue.
MLD

"Smarty" wrote in message
...
This comment opens up the possibility that wrapping the existing harness
with a braided wrap as a helix and then bonding the outer braid to a good
earth ground may help the radiated electromagnetic interference (EMI).
The
conducted noise will still need to be filtered / trapped before the
wiring
enters / exists the furnace. Given that this EMI goes from the AM band
(approx 1 MHz frequency all the way up to VHF or UHF television
frequencies,
however, the likelihood of being able to devise a good wideband filter
which
substantially reduces the conducted EMI is remote without a lot of
expense.
If the motor itself is truly the principal noise source, then getting
some
noise suppression right at the motor offers the best solution, either
with
shielding, series inductors (chokes), shunt capacitors, or all of the
above.
The motor brushes and commutating connections may be creating a lot of
arcing, and a new motor may help if it is constructed differently (from a
different vendor).

Smarty


"MLD" wrote in message
news:d6J4h.3603$Ue.2593@trndny03...
Looking back, I now recall that replacing the inducer motor wiring
harness
with one that had better shielding did make a significant improvement
although it didn't completely resolve the noise problem.
MLD


"MLD" wrote in message
news:q0J4h.5540$qG.1024@trndny02...

"modelman" wrote in message
oups.com...
Several months ago I had a high efficiency Trane XV90 natural gas
furnace and heat pump installed. Since the weather has recently
been
cold enough for the gas furnace to provide heat, I have been
experiencing severe radio interference. The interference wipes out
AM
broadcast reception throughout my house. I also see snow on a TV
connected to an external antenna.

The radio noise occurs as soon as the draft inducer motor starts up;
the pitch of the interference is related to the motor speed. The
draft
inducer motor is a dc motor driven by a PWM controller on the main
circuit board. It is well known that PWM systems generate strong
harmonics throughout the radio spectrum, resulting in radio
interference. However, properly designed PWM systems include
filtering
and shielding to suppress the radio frequency currents from the
wiring.

I contacted my installer, who is totally unfamiliar with the
problem.
The electrician who was sent to my house to investigate the problem
also doesn't understand what's going on. I had to explain the
difference between an RF ground and dc or house ground to him.
Although everything appears to be well grounded from a dc
perspective,
I suspect that portions of the system are radiating RF energy.

Several days ago I emailed Trane about the problem, but haven't
received any response.

Although there has been past discussion in this group about radio/TV
interference emanating from Trane high efficiency gas furnaces, I
haven't seen any definitive fix. Does anyone know if Trane has a
fix
for this problem. Do they have a shielded cable and or rf filter
kit
to suppress this noise? Since my system is under warranty, I won't
attempt any modiifcations to the system.

Has anyone experienced this problem?

Thanks.


Here's one guy that had the exact same problem. I was a bit luckier
that
you in that it didn't bother my AM radio signal but it did screw up my
kitchen TV picture--rabbit ears. It's coming from the inducer motor
as
you
surmised. The installer was very cooperative and tried to fix it
based
on
input from Trane. Changed out the cable to the motor with one that
was
supposed to provide better shielding and when that didn't work changed
the
control board---both without any success. Prior to and after
component
replacements I tried grounding everything that I could, again with no
success. Got the local Trane Rep on the phone; he made promises but
never
followed through with a solution. Had a new Trane for about a year
that
got
into a problem resulting in it being replaced under warranty rather
than
repaired--it was the replacement furnace that had the RF noise
problem.
Found out that Trane went to a "new design" inducer motor. I tried to
get
the Trane Rep to replace the motor with the same design that was on my
first
furnace. No luck there, was just ignored and yessed to death. If
Trane
acts
dumb about the RF noise it's all show-because mine happened about a
year
ago. My guess is that you're stuck with the problem. I finally made
mine
going away by putting in a cable line to the TV.
My suggestion in your tussle with Trane or the installer is to go find
an
inducer motor from an earlier vintage furnace. Even if it has to be
cannibalized off an older (2yrs or so) furnace.
MLD

Good point! There are FCC rules regarding interference / EMI and Trane may
have flagrantly ignored them. Maybe a threatening letter to the Customer
Service Department written with the help of those of us who are amateur
radio / electrical engineering types would force them to finally do the
right thing.


Smarty


"Mark" wrote in message
oups.com...
modelman wrote:
Several months ago I had a high efficiency Trane XV90 natural gas
furnace and heat pump installed. Since the weather has recently been
cold enough for the gas furnace to provide heat, I have been
experiencing severe radio interference. The interference wipes out AM
broadcast reception throughout my house. I also see snow on a TV
connected to an external antenna.

The radio noise occurs as soon as the draft inducer motor starts up;
the pitch of the interference is related to the motor speed. The draft
inducer motor is a dc motor driven by a PWM controller on the main
circuit board. It is well known that PWM systems generate strong
harmonics throughout the radio spectrum, resulting in radio
interference. However, properly designed PWM systems include filtering
and shielding to suppress the radio frequency currents from the wiring.

I contacted my installer, who is totally unfamiliar with the problem.
The electrician who was sent to my house to investigate the problem
also doesn't understand what's going on. I had to explain the
difference between an RF ground and dc or house ground to him.
Although everything appears to be well grounded from a dc perspective,
I suspect that portions of the system are radiating RF energy.

Several days ago I emailed Trane about the problem, but haven't
received any response.

Although there has been past discussion in this group about radio/TV
interference emanating from Trane high efficiency gas furnaces, I
haven't seen any definitive fix. Does anyone know if Trane has a fix
for this problem. Do they have a shielded cable and or rf filter kit
to suppress this noise? Since my system is under warranty, I won't
attempt any modiifcations to the system.

Has anyone experienced this problem?

Thanks.


Trane should be made to fix this and recall all the units that have
been installed. I can pick this interference up on a 2 meter receiver
in my car for blocks. The FCC should bust them if they don't fix it...

I cross posted this to some of the amateur radio groups.

Mark

Take Trane to small claims if they dont fix it. After they are served it
will be fixed in a week.

Smarty wrote:
Good point! There are FCC rules regarding interference / EMI and Trane may
have flagrantly ignored them. Maybe a threatening letter to the Customer
Service Department written with the help of those of us who are amateur
radio / electrical engineering types would force them to finally do the
right thing.


Smarty


"Mark" wrote in message
oups.com...
modelman wrote:
Several months ago I had a high efficiency Trane XV90 natural gas
furnace and heat pump installed. Since the weather has recently been
cold enough for the gas furnace to provide heat, I have been
experiencing severe radio interference. The interference wipes out AM
broadcast reception throughout my house. I also see snow on a TV
connected to an external antenna.

The radio noise occurs as soon as the draft inducer motor starts up;
the pitch of the interference is related to the motor speed. The draft
inducer motor is a dc motor driven by a PWM controller on the main
circuit board. It is well known that PWM systems generate strong
harmonics throughout the radio spectrum, resulting in radio
interference. However, properly designed PWM systems include filtering
and shielding to suppress the radio frequency currents from the wiring.

I contacted my installer, who is totally unfamiliar with the problem.
The electrician who was sent to my house to investigate the problem
also doesn't understand what's going on. I had to explain the
difference between an RF ground and dc or house ground to him.
Although everything appears to be well grounded from a dc perspective,
I suspect that portions of the system are radiating RF energy.

Several days ago I emailed Trane about the problem, but haven't
received any response.

Although there has been past discussion in this group about radio/TV
interference emanating from Trane high efficiency gas furnaces, I
haven't seen any definitive fix. Does anyone know if Trane has a fix
for this problem. Do they have a shielded cable and or rf filter kit
to suppress this noise? Since my system is under warranty, I won't
attempt any modiifcations to the system.

Has anyone experienced this problem?

Thanks.

Trane should be made to fix this and recall all the units that have
been installed. I can pick this interference up on a 2 meter receiver
in my car for blocks. The FCC should bust them if they don't fix it...

I cross posted this to some of the amateur radio groups.

Mark




First, I would get a schematic of the electronics/wiring/specs/and
installation instructions for the specific model (web is a good place
maybe.) More of a chance the installer has made an error in the
installation, grounding, shielding, etc., could save you from the
possibility of "crying wolf" too soon... I suspect the engineers of
using more caution in the design of the unit, then the installers in the
installation of the unit.

JS

Mark,

I had a severe interference MF to HF from a neighbours gas heater unit. Not
sure what it was that was causing it but it was being effectively radiated
by the external cables, power and control. I traced the interference to the
unit using a portable rx. I silenced it by wrapping both cables tightly
around a 6 inch ferrite rod. The cables held in place by cable ties and
tape. Hope this helps.

73 Alan VK6BN


"Mark" wrote in message
oups.com...
modelman wrote:
Several months ago I had a high efficiency Trane XV90 natural gas
furnace and heat pump installed. Since the weather has recently been
cold enough for the gas furnace to provide heat, I have been
experiencing severe radio interference. The interference wipes out AM
broadcast reception throughout my house. I also see snow on a TV
connected to an external antenna.

The radio noise occurs as soon as the draft inducer motor starts up;
the pitch of the interference is related to the motor speed. The draft
inducer motor is a dc motor driven by a PWM controller on the main
circuit board. It is well known that PWM systems generate strong
harmonics throughout the radio spectrum, resulting in radio
interference. However, properly designed PWM systems include filtering
and shielding to suppress the radio frequency currents from the wiring.

I contacted my installer, who is totally unfamiliar with the problem.
The electrician who was sent to my house to investigate the problem
also doesn't understand what's going on. I had to explain the
difference between an RF ground and dc or house ground to him.
Although everything appears to be well grounded from a dc perspective,
I suspect that portions of the system are radiating RF energy.

Several days ago I emailed Trane about the problem, but haven't
received any response.

Although there has been past discussion in this group about radio/TV
interference emanating from Trane high efficiency gas furnaces, I
haven't seen any definitive fix. Does anyone know if Trane has a fix
for this problem. Do they have a shielded cable and or rf filter kit
to suppress this noise? Since my system is under warranty, I won't
attempt any modiifcations to the system.

Has anyone experienced this problem?

Thanks.


Trane should be made to fix this and recall all the units that have
been installed. I can pick this interference up on a 2 meter receiver
in my car for blocks. The FCC should bust them if they don't fix it...

I cross posted this to some of the amateur radio groups.

Mark

Mark wrote:
modelman wrote:

Several months ago I had a high efficiency Trane XV90 natural gas
furnace and heat pump installed. Since the weather has recently been
cold enough for the gas furnace to provide heat, I have been
experiencing severe radio interference. The interference wipes out AM
broadcast reception throughout my house. I also see snow on a TV
connected to an external antenna.

The radio noise occurs as soon as the draft inducer motor starts up;
the pitch of the interference is related to the motor speed. The draft
inducer motor is a dc motor driven by a PWM controller on the main
circuit board. ... SNIPPED ...

DC motors are notorious noise generators. Those of us who used to be mobile when
6 VDC was the value of a car battery, and alternators did not exist, will attest
to the facts of generator [DC motor] noise.

A DC motor uses brushes to contact windings within the motor. As the motor turns
the brushes continually make and break current in the rotating armature
[inductance]. This making and breaking creates a very wide HF and lower VHF
noise spectrum. [Lots of sparks].

The solution, in the olden days, was a coaxial capacitor mounted directly to the
frame of the motor with the DC power running through the capacitor. I recall the
capacitor was about 1 inch in diameter and 2 inches long. Sprague made such a
critter.

Hope this history helps.

/s/ DD, W1MCE

Nice thought, but I went a bit down that road--I'm fuzzy about the specific
details but for one reason or another the people that I spoke to didn't give
me anything positive. Something about the generation of RF interference not
applying to a product like a furnace. Since this has been a problem for so
long and Trane has not been mandated to fix it lends some weight to what I
was told. I did tell the Trane Rep that I was going to contact someone in
higher management (VP etc) and issue a complaint at that level----didn't
phase him. Then I put in my cable line and didn't follow up. For those of
you still aggravated by the RF noise why not try this route? I guess that
if you go the way of the Small Claims Court you probably have to sue the
installer as well as Trane and it would have to be for a complete
replacement (one without the problem)or a removal and money refunded.
MLD
"Smarty" wrote in message
...
Good point! There are FCC rules regarding interference / EMI and Trane may
have flagrantly ignored them. Maybe a threatening letter to the Customer
Service Department written with the help of those of us who are amateur
radio / electrical engineering types would force them to finally do the
right thing.


Smarty


"Mark" wrote in message
oups.com...
modelman wrote:
Several months ago I had a high efficiency Trane XV90 natural gas
furnace and heat pump installed. Since the weather has recently been
cold enough for the gas furnace to provide heat, I have been
experiencing severe radio interference. The interference wipes out AM
broadcast reception throughout my house. I also see snow on a TV
connected to an external antenna.

The radio noise occurs as soon as the draft inducer motor starts up;
the pitch of the interference is related to the motor speed. The draft
inducer motor is a dc motor driven by a PWM controller on the main
circuit board. It is well known that PWM systems generate strong
harmonics throughout the radio spectrum, resulting in radio
interference. However, properly designed PWM systems include filtering
and shielding to suppress the radio frequency currents from the wiring.

I contacted my installer, who is totally unfamiliar with the problem.
The electrician who was sent to my house to investigate the problem
also doesn't understand what's going on. I had to explain the
difference between an RF ground and dc or house ground to him.
Although everything appears to be well grounded from a dc perspective,
I suspect that portions of the system are radiating RF energy.

Several days ago I emailed Trane about the problem, but haven't
received any response.

Although there has been past discussion in this group about radio/TV
interference emanating from Trane high efficiency gas furnaces, I
haven't seen any definitive fix. Does anyone know if Trane has a fix
for this problem. Do they have a shielded cable and or rf filter kit
to suppress this noise? Since my system is under warranty, I won't
attempt any modiifcations to the system.

Has anyone experienced this problem?

Thanks.


Trane should be made to fix this and recall all the units that have
been installed. I can pick this interference up on a 2 meter receiver
in my car for blocks. The FCC should bust them if they don't fix it...

I cross posted this to some of the amateur radio groups.

Mark

Dave wrote:
Mark wrote:
modelman wrote:

Several months ago I had a high efficiency Trane XV90 natural gas
furnace and heat pump installed. Since the weather has recently been
cold enough for the gas furnace to provide heat, I have been
experiencing severe radio interference. The interference wipes out AM
broadcast reception throughout my house. I also see snow on a TV
connected to an external antenna.

The radio noise occurs as soon as the draft inducer motor starts up;
the pitch of the interference is related to the motor speed. The draft
inducer motor is a dc motor driven by a PWM controller on the main
circuit board. ... SNIPPED ...

DC motors are notorious noise generators. Those of us who used to be mobile when
6 VDC was the value of a car battery, and alternators did not exist, will attest
to the facts of generator [DC motor] noise.

A DC motor uses brushes to contact windings within the motor. As the motor turns
the brushes continually make and break current in the rotating armature
[inductance]. This making and breaking creates a very wide HF and lower VHF
noise spectrum. [Lots of sparks].

The solution, in the olden days, was a coaxial capacitor mounted directly to the
frame of the motor with the DC power running through the capacitor. I recall the
capacitor was about 1 inch in diameter and 2 inches long. Sprague made such a
critter.

Hope this history helps.

/s/ DD, W1MCE

I'm pretty sure these motors don't have brushes and are electronically
commutated and the electronics are causing the EMI...
Mark

MLD wrote:
Nice thought, but I went a bit down that road--I'm fuzzy about the specific
details but for one reason or another the people that I spoke to didn't give
me anything positive. Something about the generation of RF interference not
applying to a product like a furnace.

Anything that generates RF inside the USA is regulated by the FCC. If your
cat's butt emits RF in the USA it's regulated by the FCC.

--
"A man's country is not a certain area of land, of mountains, rivers, and
woods, but it is a principle; and patriotism is loyalty to that principle."
-- George William Curtis

Mark wrote:
Dave wrote:
Mark wrote:
modelman wrote:

Several months ago I had a high efficiency Trane XV90 natural gas
furnace and heat pump installed. Since the weather has recently been
cold enough for the gas furnace to provide heat, I have been
experiencing severe radio interference. The interference wipes out AM
broadcast reception throughout my house. I also see snow on a TV
connected to an external antenna.

The radio noise occurs as soon as the draft inducer motor starts up;
the pitch of the interference is related to the motor speed. The draft
inducer motor is a dc motor driven by a PWM controller on the main
circuit board. ... SNIPPED ...

DC motors are notorious noise generators. Those of us who used to be mobile when
6 VDC was the value of a car battery, and alternators did not exist, will attest
to the facts of generator [DC motor] noise.

A DC motor uses brushes to contact windings within the motor. As the motor turns
the brushes continually make and break current in the rotating armature
[inductance]. This making and breaking creates a very wide HF and lower VHF
noise spectrum. [Lots of sparks].

The solution, in the olden days, was a coaxial capacitor mounted directly to the
frame of the motor with the DC power running through the capacitor. I recall the
capacitor was about 1 inch in diameter and 2 inches long. Sprague made such a
critter.

Hope this history helps.

/s/ DD, W1MCE

I'm pretty sure these motors don't have brushes and are electronically
commutated and the electronics are causing the EMI...
Mark

Hi Mark, Modern HVAC, dishwashers, washing machines,ect. use variable
speed drives, which increases the efficiency of the devices. The
increased efficiency produces increased RFI due to the switching action
of the solid state devices (SCR's, BJT's, IGBJT's.ect). My washing
machine drives me crazy on Sat. morning on HF as my maid does the
weekly wash. As for what you can do? I don't know, it would require
vast amounts of filtering at the drives, I am sure that Trane and
other mfgrs are not willing invest in.

This is completely different from the usual thermostat interference,
and will be much more difficult to get rid of.
Gary N4AST

Mark wrote:
Dave wrote:
Mark wrote:
modelman wrote:

Several months ago I had a high efficiency Trane XV90 natural gas
furnace and heat pump installed. Since the weather has recently been
cold enough for the gas furnace to provide heat, I have been
experiencing severe radio interference. The interference wipes out AM
broadcast reception throughout my house. I also see snow on a TV
connected to an external antenna.

The radio noise occurs as soon as the draft inducer motor starts up;
the pitch of the interference is related to the motor speed. The draft
inducer motor is a dc motor driven by a PWM controller on the main
circuit board. ... SNIPPED ...

DC motors are notorious noise generators. Those of us who used to be mobile when
6 VDC was the value of a car battery, and alternators did not exist, will attest
to the facts of generator [DC motor] noise.

A DC motor uses brushes to contact windings within the motor. As the motor turns
the brushes continually make and break current in the rotating armature
[inductance]. This making and breaking creates a very wide HF and lower VHF
noise spectrum. [Lots of sparks].

The solution, in the olden days, was a coaxial capacitor mounted directly to the
frame of the motor with the DC power running through the capacitor. I recall the
capacitor was about 1 inch in diameter and 2 inches long. Sprague made such a
critter.

Hope this history helps.

/s/ DD, W1MCE

I'm pretty sure these motors don't have brushes and are electronically
commutated and the electronics are causing the EMI...
Mark

Hi Mark, Modern HVAC, dishwashers, washing machines,ect. use variable
speed drives, which increases the efficiency of the devices. The
increased efficiency produces increased RFI due to the switching action
of the solid state devices (SCR's, BJT's, IGBJT's.ect). My washing
machine drives me crazy on Sat. morning on HF as my maid does the
weekly wash. As for what you can do? I don't know, it would require
vast amounts of filtering at the drives, I am sure that Trane and
other mfgrs are not willing invest in.

This is completely different from the usual thermostat interference,
and will be much more difficult to get rid of.
Gary N4AST

"Mark" wrote in message
oups.com...
modelman wrote:
Several months ago I had a high efficiency Trane XV90 natural gas
furnace and heat pump installed. Since the weather has recently been
cold enough for the gas furnace to provide heat, I have been
experiencing severe radio interference. The interference wipes out AM
broadcast reception throughout my house. I also see snow on a TV
connected to an external antenna.

The radio noise occurs as soon as the draft inducer motor starts up;
the pitch of the interference is related to the motor speed. The draft
inducer motor is a dc motor driven by a PWM controller on the main
circuit board. It is well known that PWM systems generate strong
harmonics throughout the radio spectrum, resulting in radio
interference. However, properly designed PWM systems include filtering
and shielding to suppress the radio frequency currents from the wiring.

I contacted my installer, who is totally unfamiliar with the problem.
The electrician who was sent to my house to investigate the problem
also doesn't understand what's going on. I had to explain the
difference between an RF ground and dc or house ground to him.
Although everything appears to be well grounded from a dc perspective,
I suspect that portions of the system are radiating RF energy.

Several days ago I emailed Trane about the problem, but haven't
received any response.

Although there has been past discussion in this group about radio/TV
interference emanating from Trane high efficiency gas furnaces, I
haven't seen any definitive fix. Does anyone know if Trane has a fix
for this problem. Do they have a shielded cable and or rf filter kit
to suppress this noise? Since my system is under warranty, I won't
attempt any modiifcations to the system.

Has anyone experienced this problem?

Thanks.


Trane should be made to fix this and recall all the units that have
been installed. I can pick this interference up on a 2 meter receiver
in my car for blocks. The FCC should bust them if they don't fix it...

I cross posted this to some of the amateur radio groups.

Mark

with the punce gotcha do u hav anyting cognet two say?



--
Posted via a free Usenet account from http://www.teranews.com

Interesting discussion, folks....

As a controls engineer and High-Voltage electrician.... as well as
delving into HVAC control of late... here's my observations...

These manufacturers will always take the cheapest route possible and
damn the consequences. This is particularly true in power and control
systems.

A whole lot of manufacturers are moving toward PWM drives on their
blowers in particular. Many solutions are an 'on-board' frequency
chopper that is integral with the blower's motor.

These choppers are cheaply built and cheaply engineered. I suppose they
thought RFI and EMI would be insignificant due to the control being
mounted on the motor... but they're noisy as hell.

Suggestions: Replace the power cables with a shielded, VFD rated cable.
Belden makes a wide variety... I think they're called the VFD classic
line. Pay close attention the unit and cable grounding. Check to be
certain your house ground and neutral connections are only tied together
at the service entrance panel of your home.

My 2 cents...

Jake

"Jake" wrote in message
news:xB85h.54$xD.43@trndny08...
Interesting discussion, folks....

As a controls engineer and High-Voltage electrician.... as well as delving
into HVAC control of late... here's my observations...

These manufacturers will always take the cheapest route possible and damn
the consequences. This is particularly true in power and control systems.

A whole lot of manufacturers are moving toward PWM drives on their blowers
in particular. Many solutions are an 'on-board' frequency chopper that is
integral with the blower's motor.

These choppers are cheaply built and cheaply engineered. I suppose they
thought RFI and EMI would be insignificant due to the control being
mounted on the motor... but they're noisy as hell.

Suggestions: Replace the power cables with a shielded, VFD rated cable.
Belden makes a wide variety... I think they're called the VFD classic
line. Pay close attention the unit and cable grounding. Check to be
certain your house ground and neutral connections are only tied together
at the service entrance panel of your home.

My 2 cents...

Jake

As Jake said.... with the addition of....
Make sure that you have proper earth grounds for your power, and the HAM
rigs/shack. That will go a long way towards eliminating RFI. Make sure that
all the bonding screws in the furnace are clean and tight, make sure that
the furnace has a proper ground also.
When I put the shack together, I drove a seperate 8ft copper ground rod, and
silver brazed #6 solid copper to it, then silver brazed the wire to the
copper ground buss on the back of the bench. All equipment grounded.....no
problem.

de n6ojn

"clifto" wrote in message
...
MLD wrote:
Nice thought, but I went a bit down that road--I'm fuzzy about the
specific
details but for one reason or another the people that I spoke to didn't
give
me anything positive. Something about the generation of RF interference
not
applying to a product like a furnace.

Anything that generates RF inside the USA is regulated by the FCC. If your
cat's butt emits RF in the USA it's regulated by the FCC.

Wrong. If the cat's butt emits RF, it's regulated by the FCC. But, digital
equipment used only in transportation vehicles - busses, cars, aircraft -
and equipment used in appliances - HVAC equipment mentioned specifically -
are exempt from Radio Frequency Device regulations. The rule says "....are
exempt from the specific technical standards and other requirements
contained in this part. The operator of the exempted device shall be
required to stop operating the device upon a finding by the Commission or
its representative that the device is causing harmful interference".

As to harmful interference, just because the noise floor rises 20db for 5
seconds on a 50 kHz segment of 20 meters when a bus passes your house, it
isn't going to be considered harmful interference. As much as you might like
to think that it is, a detectable signal from your neighbors Air Conditioner
isn't going to be considered "harmful interference". A carrier that
obliterates a specific, used - as in "there's a repeater 3 miles away
running 200 watts on 444.600, and the carrier from the Carrier (or Trane)
nukes it" - frequency might result in a letter. Just " 'cause you can hear
it" ain't gonna cut it.




47CFR15.103

Hi again Mark,

I think Jake is on the right track, whatever the source of noise inside the
unit its the mechanism that radiates the noise that needs to be attended to.
In my case it was the external cables, choking them off with ferrite sorted
out my problem. To suppress the noise at source within the unit seems a bit
hard for me. I also suspect there may be more than one noise source in the
box.

73 Alan VK6BN


"Mark" wrote
Several months ago I had a high efficiency Trane XV90 natural gas
furnace and heat pump installed. Since the weather has recently been
cold enough for the gas furnace to provide heat, I have been
experiencing severe radio interference. The interference wipes out AM

Mark wrote:
Dave wrote:
Mark wrote:
modelman wrote:

/s/ DD, W1MCE

Mark


Mark:

A quick check of the web turned up a site with posts dealing with the
same problem you are experiencing, it seems someone was able to make
some noticeable improvements in the rf interference generated--but not
totally eliminate... Just might be worth you time time to look, the
link I will paste is a long one, if it wraps you may have to copy and
paste both lines into the address bar of your browser and make sure
there have been no breaks, spaces, caused the whole link. Hope this
helps...

http://groups.google.com/group/alt.h...eb8ab594ac0781

Regards,
JS

modelman wrote:
Tony,

The interference is being radiated, since I can hear it loud and clear
on a "walkman" outside of my house. I haven't yet determined which
wiring (power line to the furnace, thermostat cables, etc) is doing
most of the radiating. When I "sniff" the wires with my walkman radio,
everything seems to be hot with the rf interference. There is no
significant change in intensity with split core ferrites (type 31
ferrite) on the thermostat cable. I haven't yet tried an EMI filter in
series with the ac line to the furnace. That would require some work
on my part, and I want to give Trane a chance to solve this problem.

Yesterday I questioned the electrician about why the furnace ground is
connected to the gas pipe; I didn't get a logical answer. He said that
is the way it's done on all installations. I pointed out that the gas
pipe is bonded to the electrical ground of the house and water pipes at
its far end about 25 feet from the furnace, providing a dc ground but
not an rf ground. I suspect that the gas pipe may be acting as an
antenna. However, there was no change in interference when the ground
is lifted from the gas pipe. A short ground connection to a ground rod
may provide a better rf ground for the furnace.

The outfit who installed my furnace promised to contact Trane today. I
hope to know more shortly about what solution Trane proposes.

Thanks.

Jack, K1VT


Tony Hwang wrote:

modelman wrote:

Several months ago I had a high efficiency Trane XV90 natural gas
furnace and heat pump installed. Since the weather has recently been
cold enough for the gas furnace to provide heat, I have been
experiencing severe radio interference. The interference wipes out AM
broadcast reception throughout my house. I also see snow on a TV
connected to an external antenna.

The radio noise occurs as soon as the draft inducer motor starts up;
the pitch of the interference is related to the motor speed. The draft
inducer motor is a dc motor driven by a PWM controller on the main
circuit board. It is well known that PWM systems generate strong
harmonics throughout the radio spectrum, resulting in radio
interference. However, properly designed PWM systems include filtering
and shielding to suppress the radio frequency currents from the wiring.

I contacted my installer, who is totally unfamiliar with the problem.
The electrician who was sent to my house to investigate the problem
also doesn't understand what's going on. I had to explain the
difference between an RF ground and dc or house ground to him.
Although everything appears to be well grounded from a dc perspective,
I suspect that portions of the system are radiating RF energy.

Several days ago I emailed Trane about the problem, but haven't
received any response.

Although there has been past discussion in this group about radio/TV
interference emanating from Trane high efficiency gas furnaces, I
haven't seen any definitive fix. Does anyone know if Trane has a fix
for this problem. Do they have a shielded cable and or rf filter kit
to suppress this noise? Since my system is under warranty, I won't
attempt any modiifcations to the system.

Has anyone experienced this problem?

Thanks.


Hi,
First you'll have to find out whether the interference is coming thru
the power line or thru the air. It can be cured but needs some expert
knowledge. Maybe Trane has noise suppressor kit of sort? Better check
with them.
Tony, VE6CGX


Hi,
That sounds like a toughie. Hope everything is tight as far as terminals
and connections go on the control board. Random noise emission is
hardest to get rid of. Reminds me of noise blankers on our receivers,
hi. My furnace is Carrier and did not enoucouter any problem.
I assume FM radio is not affected.
73,
Tony, VE6CGX

MLD wrote:

"modelman" wrote in message
oups.com...

Several months ago I had a high efficiency Trane XV90 natural gas
furnace and heat pump installed. Since the weather has recently been
cold enough for the gas furnace to provide heat, I have been
experiencing severe radio interference. The interference wipes out AM
broadcast reception throughout my house. I also see snow on a TV
connected to an external antenna.

The radio noise occurs as soon as the draft inducer motor starts up;
the pitch of the interference is related to the motor speed. The draft
inducer motor is a dc motor driven by a PWM controller on the main
circuit board. It is well known that PWM systems generate strong
harmonics throughout the radio spectrum, resulting in radio
interference. However, properly designed PWM systems include filtering
and shielding to suppress the radio frequency currents from the wiring.

I contacted my installer, who is totally unfamiliar with the problem.
The electrician who was sent to my house to investigate the problem
also doesn't understand what's going on. I had to explain the
difference between an RF ground and dc or house ground to him.
Although everything appears to be well grounded from a dc perspective,
I suspect that portions of the system are radiating RF energy.

Several days ago I emailed Trane about the problem, but haven't
received any response.

Although there has been past discussion in this group about radio/TV
interference emanating from Trane high efficiency gas furnaces, I
haven't seen any definitive fix. Does anyone know if Trane has a fix
for this problem. Do they have a shielded cable and or rf filter kit
to suppress this noise? Since my system is under warranty, I won't
attempt any modiifcations to the system.

Has anyone experienced this problem?

Thanks.



Here's one guy that had the exact same problem. I was a bit luckier that
you in that it didn't bother my AM radio signal but it did screw up my
kitchen TV picture--rabbit ears. It's coming from the inducer motor as you
surmised. The installer was very cooperative and tried to fix it based on
input from Trane. Changed out the cable to the motor with one that was
supposed to provide better shielding and when that didn't work changed the
control board---both without any success. Prior to and after component
replacements I tried grounding everything that I could, again with no
success. Got the local Trane Rep on the phone; he made promises but never
followed through with a solution. Had a new Trane for about a year that got
into a problem resulting in it being replaced under warranty rather than
repaired--it was the replacement furnace that had the RF noise problem.
Found out that Trane went to a "new design" inducer motor. I tried to get
the Trane Rep to replace the motor with the same design that was on my first
furnace. No luck there, was just ignored and yessed to death. If Trane acts
dumb about the RF noise it's all show-because mine happened about a year
ago. My guess is that you're stuck with the problem. I finally made mine
going away by putting in a cable line to the TV.
My suggestion in your tussle with Trane or the installer is to go find an
inducer motor from an earlier vintage furnace. Even if it has to be
cannibalized off an older (2yrs or so) furnace.
MLD


Hi,
If that's the case, FCC may be interested. Have you reported to FCC?

Alan Taylor wrote:

Hi again Mark,

I think Jake is on the right track, whatever the source of noise inside the
unit its the mechanism that radiates the noise that needs to be attended to.
In my case it was the external cables, choking them off with ferrite sorted
out my problem. To suppress the noise at source within the unit seems a bit
hard for me. I also suspect there may be more than one noise source in the
box.

73 Alan VK6BN


"Mark" wrote

Several months ago I had a high efficiency Trane XV90 natural gas
furnace and heat pump installed. Since the weather has recently been
cold enough for the gas furnace to provide heat, I have been
experiencing severe radio interference. The interference wipes out AM



Hi,
Then, shielding, choking, bypassing with caps come to mind. It's all by
trial and error. O'scope may come in handy.

Yes, the FCC not only has cognizance, but quite legitimately does not want
to see products throwing a lot of EMI out which cause you and perhaps your
neighbors to have reception issues. If I were at Trane handling Customer
Service and was threatened with FCC action, I would react.

Smarty


"clifto" wrote in message
...
MLD wrote:
Nice thought, but I went a bit down that road--I'm fuzzy about the
specific
details but for one reason or another the people that I spoke to didn't
give
me anything positive. Something about the generation of RF interference
not
applying to a product like a furnace.

Anything that generates RF inside the USA is regulated by the FCC. If your
cat's butt emits RF in the USA it's regulated by the FCC.

--
"A man's country is not a certain area of land, of mountains, rivers, and
woods, but it is a principle; and patriotism is loyalty to that
principle."
-- George William Curtis

Hi,
Then, shielding, choking, bypassing with caps come to mind. It's all by
trial and error. O'scope may come in handy.

Well that's my concern.
There are more and more of these kinds of units being installed
everyday.
We can't "home brew" a fix for all of them.
Someone needs to get to the FCC or to the manufacterer to fix this at
the source before it gets worse.

Mark

If you file in small claims for the nominal fee, [mine is 35$] Do you
really think Trane will fly in an atty for a day at considerable cost
and possibly loose 3000 and make local new hurting sales, or get your
furnace fixed.
I think they will fix it within 30 days. If they see your attemps to
alter it you are screwed. Start by a certified letter and many emails to
Trane and print copies. Video your interference issues-tests.

Maybe different organizations like FTC, FCC, CPSC, Consumer Reports,
etc can guide you on other complaints. This issue is not new.

RF I would think is regulated. Excessive amounts have to be of concern
of saftey for medical, security, and other equipment. Even if Trane has
figured a legal Out with the FCC, your local judge wont like it not will
Trane want to pay to go to court .

Noon-Air wrote:

SNIPPED

As Jake said.... with the addition of....
Make sure that you have proper earth grounds for your power, and the HAM
rigs/shack. That will go a long way towards eliminating RFI. Make sure that
all the bonding screws in the furnace are clean and tight, make sure that
the furnace has a proper ground also.
When I put the shack together, I drove a seperate 8ft copper ground rod, and
silver brazed #6 solid copper to it, then silver brazed the wire to the
copper ground buss on the back of the bench. All equipment grounded.....no
problem.

de n6ojn



As you describe your setup it does meet USA National Electrical Code. Your home
should have ONLY one earth connection, not two!

As you describe it, your house presumably has the electrical service panel
grounded to an 8 feet long ground rod where the service enters the house. You
seem to have added a second 8 feet ground rod to your home specifically for the
Ham station.

Check with a local electrician for specific compliance issues.

/s/ DD

wrote in message
ups.com...
Mark wrote:
Dave wrote:
Mark wrote:
modelman wrote:

Several months ago I had a high efficiency Trane XV90 natural gas
furnace and heat pump installed. Since the weather has recently been
cold enough for the gas furnace to provide heat, I have been
experiencing severe radio interference. The interference wipes out
AM
broadcast reception throughout my house. I also see snow on a TV
connected to an external antenna.

The radio noise occurs as soon as the draft inducer motor starts up;
the pitch of the interference is related to the motor speed. The
draft
inducer motor is a dc motor driven by a PWM controller on the main
circuit board. ... SNIPPED ...

DC motors are notorious noise generators. Those of us who used to be
mobile when
6 VDC was the value of a car battery, and alternators did not exist,
will attest
to the facts of generator [DC motor] noise.

A DC motor uses brushes to contact windings within the motor. As the
motor turns
the brushes continually make and break current in the rotating armature
[inductance]. This making and breaking creates a very wide HF and lower
VHF
noise spectrum. [Lots of sparks].

The solution, in the olden days, was a coaxial capacitor mounted
directly to the
frame of the motor with the DC power running through the capacitor. I
recall the
capacitor was about 1 inch in diameter and 2 inches long. Sprague made
such a
critter.

Hope this history helps.

/s/ DD, W1MCE

I'm pretty sure these motors don't have brushes and are electronically
commutated and the electronics are causing the EMI...
Mark

Hi Mark, Modern HVAC, dishwashers, washing machines,ect. use variable
speed drives, which increases the efficiency of the devices. The
increased efficiency produces increased RFI due to the switching action
of the solid state devices (SCR's, BJT's, IGBJT's.ect). My washing
machine drives me crazy on Sat. morning on HF as my maid does the
weekly wash. As for what you can do? I don't know, it would require
vast amounts of filtering at the drives, I am sure that Trane and
other mfgrs are not willing invest in.

This is completely different from the usual thermostat interference,
and will be much more difficult to get rid of.
Gary N4AST

Gentlemen Hi
and there is nothing that could be done to force OEMs
for clean up this interference (RFI?) That is nice but
you and I if interfere with some one TV in Neighborhood
FCC would be all over our ass thanks for equal justice
KA2AYS

"Dave" wrote in message
. ..
Noon-Air wrote:

SNIPPED

As Jake said.... with the addition of....
Make sure that you have proper earth grounds for your power, and the HAM
rigs/shack. That will go a long way towards eliminating RFI. Make sure
that all the bonding screws in the furnace are clean and tight, make sure
that the furnace has a proper ground also.
When I put the shack together, I drove a seperate 8ft copper ground rod,
and silver brazed #6 solid copper to it, then silver brazed the wire to
the copper ground buss on the back of the bench. All equipment
grounded.....no problem.

de n6ojn



As you describe your setup it does meet USA National Electrical Code. Your
home should have ONLY one earth connection, not two!

Actually as I live in a lightening prone area, my home has several earth
grounds as do most of the other buildings in the area.

As you describe it, your house presumably has the electrical service panel
grounded to an 8 feet long ground rod where the service enters the house.

The main service panel has 2 ground rods tied to the same buss, The TV cable
entrance has a seperate earth ground, as does the telephone entrance, and
the sub panel in the garage.

You seem to have added a second 8 feet ground rod to your home specifically
for the Ham station.

Yes and that one too.

Check with a local electrician for specific compliance issues.

done did... the sparky is the one that put the extra rods in for the service
entrance and the garage sub panel, and the city inspector signed off on it.

/s/ DD

"John Smith" wrote in message
...
Mark wrote:
Dave wrote:
Mark wrote:
modelman wrote:

/s/ DD, W1MCE

Mark


Mark:

A quick check of the web turned up a site with posts dealing with the
same problem you are experiencing, it seems someone was able to make
some noticeable improvements in the rf interference generated--but not
totally eliminate... Just might be worth you time time to look, the
link I will paste is a long one, if it wraps you may have to copy and
paste both lines into the address bar of your browser and make sure
there have been no breaks, spaces, caused the whole link. Hope this
helps...


http://groups.google.com/group/alt.h...eb8ab594ac0781

Regards,
JS


--Followed your link and was surprised to see that my comments, posted over
a year ago, are still floating around cyber space. Obviously apparent, that
the Trane RF noise problem hasn't been addressed by them. What is
disconcerting is that they have done nothing to minimize or alleviate the
problem and after more than a year are still producing furnaces with a known
RF noise generating inducer motor. Clearly a case of COST vs Customer
satisfaction---Charge more for the furnace, if that what it takes, and go
back to the motor that didn't have this problem. In my case, I had a
perfect back-to-back comparison--in the morning the first furnace worked
without incident--by noon, the new furnace was screwing up my (rabbit ears)
kitchen TV. I took a look at the new furnace and immediately saw that the
inducer motor was different--size and configuration. With a little bit of
experimentation, I finally narrowed the cause down to the inducer motor.
The installer had no clue, was very helpful and cooperative in interfacing
with Trane. Since I must have been early in the "new motor" time frame,
Trane shot-gunned the problem trying to eliminate it, ----new control board,
verifying electrical grounds, replacing the shielded motor harness (the
only thing that showed some signs of improvement). I guess at that point
they must have figured out that it was a bigger problem then they expected
and that's when the Trane Rep stopped returning my calls. It was easier to
run a cable line to the TV then to continue dealing with the installer, who
was shrugging his shoulders by this time, and the vanishing Trane Rep
MLD

"Noon-Air" wrote in message
. ..

"Dave" wrote in message
. ..
Noon-Air wrote:

SNIPPED

As Jake said.... with the addition of....
Make sure that you have proper earth grounds for your power, and the HAM
rigs/shack. That will go a long way towards eliminating RFI. Make sure
that all the bonding screws in the furnace are clean and tight, make
sure that the furnace has a proper ground also.
When I put the shack together, I drove a seperate 8ft copper ground rod,
and silver brazed #6 solid copper to it, then silver brazed the wire to
the copper ground buss on the back of the bench. All equipment
grounded.....no problem.

de n6ojn



As you describe your setup it does meet USA National Electrical Code.
Your home should have ONLY one earth connection, not two!

Actually as I live in a lightening prone area, my home has several earth
grounds as do most of the other buildings in the area.

As you describe it, your house presumably has the electrical service
panel grounded to an 8 feet long ground rod where the service enters the
house.

The main service panel has 2 ground rods tied to the same buss, The TV
cable entrance has a seperate earth ground, as does the telephone
entrance, and the sub panel in the garage.

You seem to have added a second 8 feet ground rod to your home
specifically for the Ham station.

Yes and that one too.

Check with a local electrician for specific compliance issues.

done did... the sparky is the one that put the extra rods in for the
service entrance and the garage sub panel, and the city inspector signed
off on it.

Good. Enjoy your ground loops, and have fun replacing appliances the next
time lightning hits close. Don't even think of surviving a direct strike.