I have a standard POTS line for a phone and if the extensions in the
basement and main bedroom are plugged in, the phones in the kitchen
and office play WBAL AM radio, 1090.

Can I make a simple filter to get rid of this? What size capacitor
would I use (in parallel with the phone I presume)?

Would I need a coil? I have lots of coils I have cut out of old tv's
etc, but the rating of the coil is usually not written on them, or at
least not legible.

It turns out that the phone company will provide a filter for free,
but they charge for a half-hour service call, which is like 70 or 80
dollars these days.


Remove NOPSAM to email me..

"mm" wrote in message
...

I have a standard POTS line for a phone and if the extensions in the
basement and main bedroom are plugged in, the phones in the kitchen
and office play WBAL AM radio, 1090.

Can I make a simple filter to get rid of this? What size capacitor
would I use (in parallel with the phone I presume)?

Would I need a coil? I have lots of coils I have cut out of old tv's
etc, but the rating of the coil is usually not written on them, or at
least not legible.

It turns out that the phone company will provide a filter for free,
but they charge for a half-hour service call, which is like 70 or 80
dollars these days.

Grab a ferrite clip around filter.

http://www.evertek.com/viewpart.asp?auto=22360

Have you tried using a DSL filter? They already come with male and
female phone connectors. They sell for about a dollar each at the
electronics surplus stores in Silicon Valley, and usually less than $5
at regular retail stores (although I have seen them advertised for over
$20). You may need one for each phone.

"Homer J Simpson" wrote in news:WqYYg.17305$P7.12287
@edtnps90:


"mm" wrote in message
...

I have a standard POTS line for a phone and if the extensions in the
basement and main bedroom are plugged in, the phones in the kitchen
and office play WBAL AM radio, 1090.

Grab a ferrite clip around filter.

http://www.evertek.com/viewpart.asp?auto=22360

Does anyone know whether a ferrite RFI filter like this (the kind that
goes around a cable) also attenuates voltage spikes?

Seems I recall that a typical spike lasts about a microsecond, so the
fequencies involved would be a megahertz and above, so it seems like it
might work. (Just thinking about adding them to my surge protectors.)

On 16 Oct 2006 20:58:09 -0700, "
wrote:

Have you tried using a DSL filter? They already come with male and
female phone connectors. They sell for about a dollar each at the
electronics surplus stores in Silicon Valley, and usually less than $5
at regular retail stores (although I have seen them advertised for over
$20). You may need one for each phone.

I haven't tried one because this is the first I heard. I'll look for
one. 90% of my phone calls are from my desk phone, so that ought to
be enough.

Strangely, I rarely hear the radio when the conversation starts, but
if I talk for 30 or 60 minutes, it starts and gradually gets louder
and louder until I can recognize what is said (and know what station.)

Also it has stopped for a couple months for some reason. And then
later for a few days. But when it restarted up again the second time,
I thought I should look into curing this.


Remove NOPSAM to email me..

On Tue, 17 Oct 2006 03:51:18 GMT, "Homer J Simpson"
wrote:


"mm" wrote in message
.. .

I have a standard POTS line for a phone and if the extensions in the
basement and main bedroom are plugged in, the phones in the kitchen
and office play WBAL AM radio, 1090.

Can I make a simple filter to get rid of this? What size capacitor
would I use (in parallel with the phone I presume)?

Would I need a coil? I have lots of coils I have cut out of old tv's
etc, but the rating of the coil is usually not written on them, or at
least not legible.

It turns out that the phone company will provide a filter for free,
but they charge for a half-hour service call, which is like 70 or 80
dollars these days.

Grab a ferrite clip around filter.

http://www.evertek.com/viewpart.asp?auto=22360

I may see these at hamfests. The last one of the season is this
Sunday. I'll look.

Thanks to all.

Remove NOPSAM to email me..

mm wrote:
I have a standard POTS line for a phone and if the extensions in the
basement and main bedroom are plugged in, the phones in the kitchen
and office play WBAL AM radio, 1090.

Contact the engineer at the station. They will help you. Note that
it may be your phones, not the wire.

Geoff.
--
Geoffrey S. Mendelson, Jerusalem, Israel N3OWJ/4X1GM
IL Voice: (07)-7424-1667 Fax ONLY: 972-2-648-1443 U.S. Voice: 1-215-821-1838
Visit my 'blog at http://geoffstechno.livejournal.com/

mm wrote:
I have a standard POTS line for a phone and if the extensions in the
basement and main bedroom are plugged in, the phones in the kitchen
and office play WBAL AM radio, 1090.

Easiest is to find a DSL line filter. They're just the right specs for
killing AM band signals. Plug it in series with the loudest phone.

If you can't get one of those, try a 0.01uF to 0.05uF capacitor,
across the red and green wires. You may need one at EACH phone jack.

Way back when I used to live in the shadow of a 50KW AM station, it
took a pair of capacitors across the phone line, with 2.5mH chokes in
series, to eliminate the background chatter. But you can probably get
by with less than that.

mm wrote:

I have a standard POTS line for a phone and if the extensions in the
basement and main bedroom are plugged in, the phones in the kitchen
and office play WBAL AM radio, 1090.

Can I make a simple filter to get rid of this? What size capacitor
would I use (in parallel with the phone I presume)?

Unless that radio station is very close to you, the problem is likely
caused by a corroded connection. You can filter it out, but if you
can find the connection and clean it you'll solve it too. One
problem with this is that the problem may exist internally in one
of the phones. But you can track that down easily by unplugging
phones.

This happens all the time with music equipment. Poor connections
on cables start tuning local radio stations. All you really need
to make an old fashion crystal radio is a diode. Corroded connections
can do a fine job at this. Then the capacitance and inductance
in the rest of the amplifier functions as the tuning stage.

In article .com,
Ancient_Hacker wrote:

In 1975 when I moved my bussiness to a building a quarter mile from an
AM station we could hear it on the phone. The phone co. sent out people
two times and put various filters on the line all to no avail. Finally
on the third visit an old timer who looked about to retire came in, put
a small mylar type cap across the ear end terminals in the handset. No
more problem, not ever on other extensions when they were put in.

Chuck P.

MOP CAP wrote:
In article .com,
Ancient_Hacker wrote:

In 1975 when I moved my bussiness to a building a quarter mile from an
AM station we could hear it on the phone. The phone co. sent out people
two times and put various filters on the line all to no avail. Finally
on the third visit an old timer who looked about to retire came in, put
a small mylar type cap across the ear end terminals in the handset. No
more problem, not ever on other extensions when they were put in.


This was a standard fix back then. I also probably saw it in one of the
ARRL handbooks. That was the first thing I was going to say. Ferrite
filters on the phone lines, handsets, power cords, should help. I would
put an MOV across the phone line at the service entrance. Actually one
on each line to ground. Good power surge suppressors have inductors and
caps after the MOV's to filter RF and the spikes caused when MOV's are
in action.

greg

"Jim Land" wrote in message
. 3.44...

Does anyone know whether a ferrite RFI filter like this (the kind that
goes around a cable) also attenuates voltage spikes?

Bound to. Even plain wire will do that and the filter will do it more.

Ancient_Hacker wrote:
mm wrote:
I have a standard POTS line for a phone and if the extensions in the
basement and main bedroom are plugged in, the phones in the kitchen
and office play WBAL AM radio, 1090.

Easiest is to find a DSL line filter. They're just the right specs for
killing AM band signals. Plug it in series with the loudest phone.

If you can't get one of those, try a 0.01uF to 0.05uF capacitor,
across the red and green wires. You may need one at EACH phone jack.

Way back when I used to live in the shadow of a 50KW AM station, it
took a pair of capacitors across the phone line, with 2.5mH chokes in
series, to eliminate the background chatter. But you can probably get
by with less than that.

I lived one street over from a 27.5kW (ERP) FM radio station in
suburban Cleveland in the early 1970s; I could see the station's tower
from my third-floor bedroom window at night. The signal didn't get into
the telephones in the house where I was living at the time, but I was
hearing the station darn nearly everyplace else--on my TV sets on
channel 6, between local stations on an FM/stereo radio (cheap offshore
brand), even in an Ampex Micro 88 cassette tape recorder my dad had. I
didn't know much about this type of interference in those days, much
less how to deal with it, but I lived in that suburb only three years,
so I didn't have to tolerate the problem very long. I now live in a
small town located about five miles from a 1kW AM station. The
station's signal doesn't get into my telephones or anything else
electronic in my apartment (except my AM radios, of course), but during
the day I can hear the station at two points on the AM radio dial--1460
kHz (the station's fundamental frequency) and 560 kHz, 0.9 MHz (900
kHz) away. The problem is still there at night, but less noticeable as
the station reduces power to 1kW after sundown.

I didn't realize that line filters such as are used on telephone
lines carrying DSL Internet service (to prevent the DSL signals from
interfering with regular telephone usage) could also be used to filter
out AM broadcast interference. You learn something new every day, I
guess, which is one reason I read these forum posts all the time (they
arrive each day in my inbox in digest format).

Every now and then I can hear another cordless phone when I am using
my own SBC 900-MHz phone, and I even get interference at times, not
very often, that sounds like crossed wires on my corded phone as well.
I guess that's one drawback of living in an apartment building; the
fact that all devices (radios, televisions, cordless telephones, etc.)
certified to comply with Part 15 regulations must accept any and all
interference they may receive is annoying at times as well, but that's
life in the 21st century, like it or not.

73 (best of regards),

Jeff Strieble, WB8NHV (email addy not shown to deter spammers)
Fairport Harbor, Ohio USA

Homer J Simpson wrote:

Grab a ferrite clip around filter.


Those clip-around filters are really good at high-frequencies, but at
the AM band they're kinda negligible impedance. You need something in
the millihenry range, not the low microhenries.

"Ancient_Hacker" wrote in message
ups.com...

Those clip-around filters are really good at high-frequencies, but at
the AM band they're kinda negligible impedance. You need something in
the millihenry range, not the low microhenries.

Buy an audio or power transformer, strip it down and re assemble around the
power line?

mm wrote:
I have a standard POTS line for a phone and if the extensions in the
basement and main bedroom are plugged in, the phones in the kitchen
and office play WBAL AM radio, 1090.

Can I make a simple filter to get rid of this? What size capacitor
would I use (in parallel with the phone I presume)?

Would I need a coil? I have lots of coils I have cut out of old tv's
etc, but the rating of the coil is usually not written on them, or at
least not legible.

It turns out that the phone company will provide a filter for free,
but they charge for a half-hour service call, which is like 70 or 80
dollars these days.


Remove NOPSAM to email me..


Are there any unused wires in the phone cables? Try grounding them.
For instance,when they ran the phone wiring here,they used CAT-5..We had
two phone lines at the time (one mostly used for a dial-up
connection),so there 4 unused wires in the CAT-5 cables..I went out to
the phone box,and connected the unused wires to the earth ground connection.
It killed the bit of cross-talk we had and some of the noise,and the
dial-up modem would connect at a faster speed.
I even went as far as to connect the extra grounded wires to the unused
contacts in the phone jacks at a couple spots,to use the "extra" pair of
wires (yellow and black) in the (long) phone cord runs to act as a
quasi-shield also.But that trick only works with 4 conductor phone
cords,not the cheaper 2 conductor ones.

On Tue, 17 Oct 2006 09:11:03 +0000 (UTC), (Geoffrey
S. Mendelson) wrote:

mm wrote:
I have a standard POTS line for a phone and if the extensions in the
basement and main bedroom are plugged in, the phones in the kitchen
and office play WBAL AM radio, 1090.

Contact the engineer at the station. They will help you. Note that
it may be your phones, not the wire.

Thanks to everyone who answered. Your answer turned out to be on the
money.

I had a phone, but found one at a rummage sale that displays the
number I just dialed. Since I'm never sure, I started using thzt
phone, but I guess I had the downstairs phones unplugged then, and
didn't notice the AM radio interference then, because it didn't start
until I plugged them back in. And when I did that, I didn't put 2 and
2 together.

A year or more later, the new phone stopped working! Maybe I dropped
it too many times, but I can't hear anything. So I went to a
Southwestern Bell Sleekline phone (shaped like a Trimline), where the
interference problem was much worse. I didn't think that associated
with any Bell company could be that cheap.***

After a week or two I changed back to the previous phone, made by
Master, a brand I have never heard of (except for padlocks) and it has
NO radio interference**. It seems one can't go by brand too much.



**(although there is the slightest hum or whisper when the downstairs
phones are plugged in**. I changed one of the downstairs phones from
Stromberg to some cheap phone and that didn't make any difference, but
that is only one extension out of 3 on that section of wire. Not
enough to worry about. I changed phones largely because the Stromberg
needed a thorough cleaning.)

***I got the SWBell Sleekline, still looking brand new with the
"features" sticker on it, at a rummage sale or hamfest for free or a
dollar, and found that the Redial didn't work right, and I think even
the Flash didn't work right, plus the AM radio interference. That's
why it was cheap. I"m not complaining. It still works as a phone.

Geoff.


If you are inclined to email me
for some reason, remove NOPSAM :-)

On Thu, 19 Oct 2006 02:02:45 -0700, PhattyMo
wrote:

mm wrote:
I have a standard POTS line for a phone and if the extensions in the
basement and main bedroom are plugged in, the phones in the kitchen
and office play WBAL AM radio, 1090.


Are there any unused wires in the phone cables? Try grounding them.

This seemed like a really good and easy idea also, and I was going to
do it, but as the other post says, I found the problem when I had to
replace the phone that caused the problem, after it broke.

Thanks.

For instance,when they ran the phone wiring here,they used CAT-5..We had
two phone lines at the time (one mostly used for a dial-up
connection),so there 4 unused wires in the CAT-5 cables..I went out to
the phone box,and connected the unused wires to the earth ground connection.
It killed the bit of cross-talk we had and some of the noise,and the
dial-up modem would connect at a faster speed.
I even went as far as to connect the extra grounded wires to the unused
contacts in the phone jacks at a couple spots,to use the "extra" pair of
wires (yellow and black) in the (long) phone cord runs to act as a
quasi-shield also.But that trick only works with 4 conductor phone
cords,not the cheaper 2 conductor ones.


If you are inclined to email me
for some reason, remove NOPSAM :-)

On 17 Oct 2006 03:22:51 -0700, "Ancient_Hacker"
wrote:


mm wrote:
I have a standard POTS line for a phone and if the extensions in the
basement and main bedroom are plugged in, the phones in the kitchen
and office play WBAL AM radio, 1090.

Easiest is to find a DSL line filter. They're just the right specs for
killing AM band signals. Plug it in series with the loudest phone.

I was definitely going to do this. I talked to a phone company guy
who said that rather than get one from him, and pay for a half hour
phone company labor, I could get one at Radio Shack! But they
wanted 15 dollars. That's still sounds like real money to me.
Especially if I might end up needing more than one.

And after all, this is a repair newsgroup, which to me always means
replacing or adding the smallest part which will do the job.

If you can't get one of those, try a 0.01uF to 0.05uF capacitor,

So this was my first choice. Thanks, and thanks especially for being
the only one to address my specific question, which was, What size
capacitor would I use.

Even though the problem is solved at this time in this place, I'm
going to get one or two of these out of my stock of miscellaneous
parts, or maybe just buy a few from Mouser.

across the red and green wires. You may need one at EACH phone jack.

Does it matter if they are polarized or not?

Way back when I used to live in the shadow of a 50KW AM station, it
took a pair of capacitors across the phone line, with 2.5mH chokes in
series, to eliminate the background chatter. But you can probably get
by with less than that.

Still I appreciate the suggested value for later, more serious cases
that may arise.

Thanks.

If you are inclined to email me
for some reason, remove NOPSAM :-)

mm wrote:
On 17 Oct 2006 03:22:51 -0700, "Ancient_Hacker"
wrote:


mm wrote:
I have a standard POTS line for a phone and if the extensions in the
basement and main bedroom are plugged in, the phones in the kitchen
and office play WBAL AM radio, 1090.

Easiest is to find a DSL line filter. They're just the right specs for
killing AM band signals. Plug it in series with the loudest phone.

I was definitely going to do this. I talked to a phone company guy
who said that rather than get one from him, and pay for a half hour
phone company labor, I could get one at Radio Shack! But they
wanted 15 dollars. That's still sounds like real money to me.
Especially if I might end up needing more than one.

ALL Electronics sells DSL filters for around $3 apiece.

Jerry

On Sat, 16 Dec 2006 21:13:12 GMT, Jerry Peters
wrote:

mm wrote:
On 17 Oct 2006 03:22:51 -0700, "Ancient_Hacker"
wrote:


mm wrote:
I have a standard POTS line for a phone and if the extensions in the
basement and main bedroom are plugged in, the phones in the kitchen
and office play WBAL AM radio, 1090.

Easiest is to find a DSL line filter. They're just the right specs for
killing AM band signals. Plug it in series with the loudest phone.

I was definitely going to do this. I talked to a phone company guy
who said that rather than get one from him, and pay for a half hour
phone company labor, I could get one at Radio Shack! But they
wanted 15 dollars. That's still sounds like real money to me.
Especially if I might end up needing more than one.

ALL Electronics sells DSL filters for around $3 apiece.

Thanks. I just noticed your post. I'm going to get one or two.



Jerry


If you are inclined to email me
for some reason, remove NOPSAM :-)

mm wrote:
ALL Electronics sells DSL filters for around $3 apiece.

Thanks. I just noticed your post. I'm going to get one or two.



Jerry

From my experience:
The 'pigtail' type filters are only two wire connections for a single
phone line. If you use the other two wires, like a 2 line phone, they
don't work on that extra line

I've seen two types of pigtail filters: both cost around 10 to 12
1) simple single cap across the line - don't work well
2) common mode choke and cap - work very well

the choke looks like one of those 1/4 inch 600 ohm audio transformers,
actually has laminated core in it

Sometimes radio stations change their beam pattern to satisfy FCC
requirements. Depending on the time of day, you may see different
influences from that AM station. Like dusk, 6pm or so.

In Aptos, California near the 10KW AM radio station, the Station's
Engineer kindly supplied the excellent pigtail line filters to nearby
residents, who asked for them, at no charge, as a 'public relations
courtesy'

You mentioned that the effect gets worse with time OFF HOOK. Very
interesting, because ON HOOK you have high voltage and ON HOOK there is
lower voltage. Perhaps there is corrosion that is detecting the AM
signal.

Even using pigtails, keep in mind that *if* your lines are unbalanced,
the audio can get into them because the protection block is nonlinear
and detects AM. Once the audio is on your lines, it cannot be blocked
at any phone, because it is now legitimate audio.

- Robert -