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Default Two rsignals at same time, 88.1 where

Satruday, july 28, at 10:50AM I was driving through Westminster Md,
listening to 88.1 FM, Baltimore,and I was getting two copies of the same
sounds, one a second or so delayed compared to the other.

This went on for at least 5 miles, at least 10 minutes.

It was nearly impossible to tell what was being said.

How could this happen?

It's a rural area with no very tall buildings and even if there were a
reflection, it would not reflect at me everywhere along a 5 mile line.

I've been there many times before, usually listening to the same
station, and it never happened before. So I don't think there is a
second station on the same frequency in radio range.


Could it be that the transmitter itself was sending out two copies of
the sound, one second apart?


After about 10 minutes, it stopped and the sound was good again.
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Default Two rsignals at same time, 88.1 where

On Tuesday, July 31, 2018 at 4:02:55 AM UTC-4, micky wrote:
Satruday, july 28, at 10:50AM I was driving through Westminster Md,
listening to 88.1 FM, Baltimore,and I was getting two copies of the same
sounds, one a second or so delayed compared to the other.

This went on for at least 5 miles, at least 10 minutes.

It was nearly impossible to tell what was being said.

How could this happen?


Have you thought of calling and telling that radio station?
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Default Two rsignals at same time, 88.1 where

On 07/31/2018 04:02 AM, micky wrote:
Satruday, july 28, at 10:50AM I was driving through Westminster Md,
listening to 88.1 FM, Baltimore,and I was getting two copies of the same
sounds, one a second or so delayed compared to the other.

This went on for at least 5 miles, at least 10 minutes.

It was nearly impossible to tell what was being said.

How could this happen?

It's a rural area with no very tall buildings and even if there were a
reflection, it would not reflect at me everywhere along a 5 mile line.

I've been there many times before, usually listening to the same
station, and it never happened before. So I don't think there is a
second station on the same frequency in radio range.


Could it be that the transmitter itself was sending out two copies of
the sound, one second apart?


After about 10 minutes, it stopped and the sound was good again.


Well, to be multipath the echo would have to be coming from 150,000 km
away, so that isn't too likely.

Maybe a repeater that got out of sync?

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC
Optics, Electro-optics, Photonics, Analog Electronics

160 North State Road #203
Briarcliff Manor NY 10510

hobbs at electrooptical dot net
http://electrooptical.net
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Default Two rsignals at same time, 88.1 where

On Tuesday, July 31, 2018 at 3:02:55 AM UTC-5, micky wrote:
Satruday, july 28, at 10:50AM I was driving through Westminster Md,
listening to 88.1 FM, Baltimore,and I was getting two copies of the same
sounds, one a second or so delayed compared to the other.

This went on for at least 5 miles, at least 10 minutes.

It was nearly impossible to tell what was being said.

How could this happen?

It's a rural area with no very tall buildings and even if there were a
reflection, it would not reflect at me everywhere along a 5 mile line.

I've been there many times before, usually listening to the same
station, and it never happened before. So I don't think there is a
second station on the same frequency in radio range.


Could it be that the transmitter itself was sending out two copies of
the sound, one second apart?


After about 10 minutes, it stopped and the sound was good again.


We have a local AM radio station that on a daily basis, I can hear two or more commercials playing on top of each other. Typically gets corrected before the programming starts again. I think I'm hearing a locally fed commercial and a network based spot at the same time. Sometimes both over traffic or weather... Just poor production.
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Default Two rsignals at same time, 88.1 where

On 7/31/2018 1:02 AM, micky wrote:
Satruday, july 28, at 10:50AM I was driving through Westminster Md,
listening to 88.1 FM, Baltimore,and I was getting two copies of the same
sounds, one a second or so delayed compared to the other.

This went on for at least 5 miles, at least 10 minutes.

It was nearly impossible to tell what was being said.

How could this happen?

It's a rural area with no very tall buildings and even if there were a
reflection, it would not reflect at me everywhere along a 5 mile line.

I've been there many times before, usually listening to the same
station, and it never happened before. So I don't think there is a
second station on the same frequency in radio range.


Could it be that the transmitter itself was sending out two copies of
the sound, one second apart?


After about 10 minutes, it stopped and the sound was good again.


Very likely an out of sync repeater. It looks like they have 2 repeaters.
http://www.wypr.org/your-public-radio-fcc-public-file


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Default Two rsignals at same time, 88.1 where

On Tue, 31 Jul 2018 07:12:49 -0700, Bob F wrote:

Very likely an out of sync repeater. It looks like they have 2 repeaters.
http://www.wypr.org/your-public-radio-fcc-public-file


Agreed, but WYPR only simulcasts with one station on 88.1MHz (WYPF):
https://en.wikipedia.org/wiki/WYPR
The station broadcasts on 88.1 MHz on the FM band. Its
studio is in the Charles Village neighborhood of
northern Baltimore, while its transmitter is in
Park Heights. The station is simulcast in the
Frederick and Hagerstown area on WYPF (88.1 FM) and
in the Ocean City area on WYPO (106.9 FM).

For a generic FM broadcast receiver, capture effect requires that one
signal is 2dB more than the other in order to get a 30dB of reduction
in "noise" from the weaker station. If the two signals are roughly
equal at the receiver, then you'll get no isolation and hear both
stations. Since KYPR and WYPF are both on 88.1 and fairly close to
each other, my guess(tm) is that their transmit frequencies are both
phase locked to some common reference, and that their audio feeds are
adjusted for identical delays. In other words, they're setup for
simulcast. However, that's a guess(tm) because I'm in a rush and
don't have time to read exactly what they're doing.


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150 Felker St #D
http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
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Default Two rsignals at same time, 88.1 where

Gonna chime in on the out-of-sync thing. Here in the office, I stream WRTI on the computer, despite the wretched sound, as the radio is not reliable. I am 15' underground and dead-center in a city-block large hospital complex.. But those few times I can get WRTI on FM, the stream is about 1/2 second behind the OTA signal. So something causing cross-talk, or something going out-of-sync and affecting OTA signal makes perfect sense.

Peter Wieck
Melrose Park, PA
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Default Two rsignals at same time, 88.1 where

On Tuesday, July 31, 2018 at 12:19:46 PM UTC-5, wrote:
Gonna chime in on the out-of-sync thing. Here in the office, I stream WRTI on the computer, despite the wretched sound, as the radio is not reliable.. I am 15' underground and dead-center in a city-block large hospital complex. But those few times I can get WRTI on FM, the stream is about 1/2 second behind the OTA signal. So something causing cross-talk, or something going out-of-sync and affecting OTA signal makes perfect sense.

Peter Wieck
Melrose Park, PA


In my house -- DirecTV is about 8 seconds behind broadcast.

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Default Two rsignals at same time, 88.1 where

Satruday, july 28, at 10:50AM I was driving through Westminster Md,
listening to 88.1 FM, Baltimore,and I was getting two copies of the same
sounds, one a second or so delayed compared to the other.

This went on for at least 5 miles, at least 10 minutes.

It was nearly impossible to tell what was being said.

How could this happen?


One possibility is that the station has one or more "repeater"
transmitters on the same frequency, intended to increase its coverage
area. The repeaters would be getting a feed of the stations's audio
signal through some sort of dedicated link... and if this link is
digital it might very well have a significant amount of latency and
buffering.

If you were then driving through a "fringe reception" area, where your
radio was receiving nearly-equal-strength signals from the primary
tranmitter and a repeater transmitter, you could have heard an
overlapping mix of audio from the two. FM receivers will typically
"capture" one or the other signal, if one is stronger than the other
by a couple of dB (the "capture ratio") but you can end up with a
non-capture situation if both signals are very close in strength. The
audio might have fluttered back and forth between the two as you
drove, as the result of "picket fence" variations in the signal
strengths of the two signals. Yeah, that would result in a rather
unintelligible signal.

And... aha! Baltimore 88.1 is WYPR, and according to Wikipedia, they
have a simulcast transmitter on the same frequency operating as WYPF
in the Frederick/Hagerstown area. Westminster is just about
equidistant from Frederick and Baltimore. WYPF's transmitter is in
the forest just north of Frederick, while WYPR's is near Druid Hill
Park is Baltimore.

So, that's my guess - fringe-area signal overlap, with one of the two
signals having a one-second audio delay in its transmission path that
the other signal does not have.



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Default Two rsignals at same time, 88.1 where

In alt.home.repair, on Tue, 31 Jul 2018 07:50:24 -0700, Jeff Liebermann
wrote:

On Tue, 31 Jul 2018 07:12:49 -0700, Bob F wrote:

Very likely an out of sync repeater. It looks like they have 2 repeaters.
http://www.wypr.org/your-public-radio-fcc-public-file


You almost convinced me of this, but Jeff reminded me... and then what
he said convinced me you are right too.

Agreed, but WYPR only simulcasts with one station on 88.1MHz (WYPF):
https://en.wikipedia.org/wiki/WYPR
The station broadcasts on 88.1 MHz on the FM band. Its
studio is in the Charles Village neighborhood of
northern Baltimore, while its transmitter is in
Park Heights.


It's about 1200 feet from TV Hill, where almost all the tv xmitters are.

The station is simulcast in the
Frederick and Hagerstown area on WYPF (88.1 FM) and


This doesn't yet solve the current question but it does answer another I
never posted.

WYPR's reception is strong in Baltimore and its suburbs, but west,
northwest, north of the suburbs, or all 3, the reception is weak and
it's actually easier to get the NPR station in DC, maybe 40 miles
farther south. I wrote to YPR about this one time but they
misunderstood my letter.

So a few weeks ago I was south of Hagerstown, which is 70 miles or so
west of Baltimore, and amazed to get WYPR. Now I realize I was getting
WYPF, only 20 miles away. I knew about that station but not that it
was on the same frequency. There are occasional announcements about all
the stations that play the same programming, but they don't include the
frequencies.

in the Ocean City area on WYPO (106.9 FM).


I've listened to that too when I'm in southern Delaware.

For a generic FM broadcast receiver, capture effect requires that one
signal is 2dB more than the other in order to get a 30dB of reduction
in "noise" from the weaker station. If the two signals are roughly
equal at the receiver, then you'll get no isolation and hear both
stations. Since KYPR and WYPF are both on 88.1 and fairly close to
each other, my guess(tm) is that their transmit frequencies are both
phase locked to some common reference,


Is that because if they weren't, one could be a half wave out of sync,
and where both could be received, one would cancel out the other?

But the syncing failed for 10 minutes? And it was working other times
I was in on that same road.

It turns out I was only 27.6 miles from the WYPF transmitter:
?hl=en

And it's 25.2 miles from the YPR xmitter. Part of the time, since I was
moving, the distances were even closer.

and that their audio feeds are
adjusted for identical delays. In other words, they're setup for
simulcast. However, that's a guess(tm) because I'm in a rush and
don't have time to read exactly what they're doing.


Any other ideas since you're back.


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Default Two rsignals at same time, 88.1 where

Hold on a minute here. You can't just throw 2 signals through the IF strip and then the limiter. the signal would be a mess and neither would be intelligible.

Or would it ? Do digital FM detectors have the capability to do that ? Pretty sure a quadrature detector doesn't. In fact the limiter stage would be one of the main things making a mess out of the signal. That assumes that no earlier stage has clipped.

It can't be the image frequency because the same thing would happen, plus the fact that even at 87.9, the bottom of the band, the image frequency is 21.4 MHz apart. So like 87,9 + 21.4 is 108.3 on a band that ends at 107.9. Or if converted the other way, 107.9 - 21.4, still off the commercial FM band.

Still only 1 carrier makes it to the detector unscathed. It may not seem logical but that means the only way is be 2 signals hetrodyning. That is not to say that there is not a carrier out there that doesn't belong.

Am I wrong here ? Two carriers ? Just how would that work ?
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Default Two rsignals at same time, 88.1 where

In article ,
wrote:
Hold on a minute here. You can't just throw 2 signals through the IF strip and then the limiter. the
signal would be a mess and neither would be intelligible.


The signal does tend to be a mess, but you can end up with semi-
intelligible audio, especially if you're moving, and the relative
strengths of the two signals are varying a lot.

Am I wrong here ? Two carriers ? Just how would that work ?


Well, here's how I see/understand it.

Both RF signals come through the front end and the mixer. The signal
entering the first part of the IF strip is a down-mixed (10.7 MHz)
combination of the two, with the relative IF strengths of the two
being proportional to the corresponding RF signal strengths.

As this "combination" signal goes through the first part of the IF
strip, it's amplified linearly... nothing distinguishes the two
signals.

The interesting thing happens when the amplified IF signal is strong
enough to limit. This is where the stronger signal wins (usually).

If one RF/IF signal is a lot stronger than the other (say, 10 dB or
more), it's the one which limits. The detector/discriminator "sees"
only this signal - the other one's contributions are too small to be
detected - the detector is fully "captured". You hear the audio from
this signal.

If the difference is smaller (say, 2 dB), the stronger signal
limits and "captures" the detector and you hear its audio. However,
the presence of the weaker signal in the detector input can
perturb the detector enough to have some audible effect... an increase
in distortion, or a faint "growling" sound. In the ham FM-repeater
community we call this "doubling". As the difference between the
signals grows less, and you fall towards the detector's "capture
ratio threshold", the doubling growl/distortion grows worse.

When the two signals are of nearly the same strength, neither signal
is detected properly... you either hear silence, or nothing but
doubling growl/buzzing.

Now, consider the case the OP was talking about, where he's driving
(not stationary). Under these conditions, the RF paths from the
transmitters to his radio are constantly changing. It's quite common
for there to be a large amount of signal-strength variation, from
moment to moment... variations of 10 or 20 dB or more are not
uncommon, due to multipath cancellations and reinforcements,
reflections and diffractions, etc.

When listening to a single transmitter of sufficient strength, you
don't notice this at all - with enough IF gain, the detector still
gets a fully-limited signal and there's no noise.

When listening to a single transmitter with a weaker signal, you hear
"picket fencing" - bursts of noise and distortion each time the signal
strength drops too low, and the detector no longer gets a clean,
limited signal.

Now, throw in a second transmitter, also weaker, in a different
direction. The signals from the two transmitters will be
picket-fencing in a completely un-correlated manner, because they're
coming from different directions.

At one instant, one may be strong and the other weak, and you hear the
first signal. A moment later, you've moved 50 feet, and the opposite
is true - A is weak, B is strong, and you hear B. Somewhere in
between those two locations, the signal strengths were nearly equal,
neither captures the limiter, you hear neither cleanly (just silence,
or a burst of noise and buzzing, or etc.).

In effect, the audio ends up "chopping" back and forth between the two
transmitters' signals, at a rate of anywhere up to multiple times per
second, with noise and distortion thrown in during the chopping.

That is, I think, what the OP was hearing. I've heard essentially the
same effect when crossing the boundary between the service areas of two
different (utterly unrelated) FM stations on the same channel. In this
case the audio programs were completely different - one was not a
delayed version of the other - but the RF issues were the same.


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Default Two rsignals at same time, 88.1 where

On Tue, 31 Jul 2018 16:16:40 -0400, micky
wrote:

In alt.home.repair, on Tue, 31 Jul 2018 07:50:24 -0700, Jeff Liebermann
wrote:

On Tue, 31 Jul 2018 07:12:49 -0700, Bob F wrote:

Very likely an out of sync repeater. It looks like they have 2 repeaters.
http://www.wypr.org/your-public-radio-fcc-public-file


You almost convinced me of this, but Jeff reminded me... and then what
he said convinced me you are right too.


Well, I did make a few minor mistakes. The terms "repeater",
translator", and "simulcast" have very specific meanings, which I
managed to mangle. Part of the problems is that I don't know what
WYPR is doing with both transmitters on 88.1MHz. Are they simulcast
transmitters, or is WYPF a repeater? Dunno and still to lazy/busy to
do the research.

This doesn't yet solve the current question but it does answer another I
never posted.


Sorry, but my crystal ball is being overhauled and I can't provide
answers to unasked questions without it.

WYPR's reception is strong in Baltimore and its suburbs, but west,
northwest, north of the suburbs, or all 3, the reception is weak...


These might help:
https://radio-locator.com/info/WYPR-FM
https://radio-locator.com/cgi-bin/patg?id=WYPR-FM

https://radio-locator.com/info/WYPF-FM
https://radio-locator.com/cgi-bin/patg?id=WYPF-FM

https://radio-locator.com/info/WYPO-FM
https://radio-locator.com/cgi-bin/patg?id=WYPO-FM

Notice that the Google Maps are gone, thanks to a Google fee increase.

So a few weeks ago I was south of Hagerstown, which is 70 miles or so
west of Baltimore, and amazed to get WYPR. Now I realize I was getting
WYPF, only 20 miles away.


If they were really simulcasting (phase locked RF and audio), you
would not be able to tell which one you were listing to.

I knew about that station but not that it
was on the same frequency. There are occasional announcements about all
the stations that play the same programming, but they don't include the
frequencies.


They should include the frequencies with the station identification.
We have several local conglomerations of stations that take quite a
while to identify all the stations that are simulcasting the same
programming. For example:
https://www.kdfc.com/listen/kdfc-coverage-maps/
However, each of the 5 transmitters are on different frequencies.

For a generic FM broadcast receiver, capture effect requires that one
signal is 2dB more than the other in order to get a 30dB of reduction
in "noise" from the weaker station. If the two signals are roughly
equal at the receiver, then you'll get no isolation and hear both
stations. Since KYPR and WYPF are both on 88.1 and fairly close to
each other, my guess(tm) is that their transmit frequencies are both
phase locked to some common reference,


Is that because if they weren't, one could be a half wave out of sync,
and where both could be received, one would cancel out the other?


Yep, or something like that. Without phase locked simulcasting of the
transmitters, there would be a large number of dead spots and possibly
some low frequency heterodyne tones.

But the syncing failed for 10 minutes? And it was working other times
I was in on that same road.


The fact that you were moving is important. If the signal levels from
each transmitter was roughly equal, you would be moving through zones
where one or the other transmitter is stronger and "captures" the
transmitter with the lesser signal. Since you were moving, the
strongest transmitter will switch back and forth between the two
stations erratically. Since something failed on the audio delay
system, every time your receiver switched between the two stations,
the audio would change accordingly.

It turns out I was only 27.6 miles from the WYPF transmitter:
?hl=en

And it's 25.2 miles from the YPR xmitter. Part of the time, since I was
moving, the distances were even closer.


So, it's likely that the signal levels were roughly the same, which is
ideal for creating the problem.

Any other ideas since you're back.


Nope.

--
Jeff Liebermann
150 Felker St #D
http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
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Default Two rsignals at same time, 88.1 where

Y'all are making this far too complicated and inventing explanations other than a simple sync issue within the station itself. Could be as simple as a tech replacing a piece of equipment and dropping a jumper into the wrong jack. 10 minutes later - after the phones started ringing off the hook - it got fixed.

William of Occam suggested that we eschew needless complexity.

Peter Wieck
Melrose Park, PA
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Default Two rsignals at same time, 88.1 where

On Wed, 1 Aug 2018 05:13:48 -0700 (PDT), "
wrote:

Y'all are making this far too complicated and inventing explanations other
than a simple sync issue within the station itself. Could be as simple as
a tech replacing a piece of equipment and dropping a jumper into the
wrong jack. 10 minutes later - after the phones started ringing off
the hook - it got fixed.


I doubt if more than few listeners heard the problem. In order to
hear both transmitters switching back and forth, the listener would
need to be:
1. Roughly equal distant from both stations or in an area where the
signal strengths are about the same.
2. In a moving vehicle, train, bus, or whatever.
3. Have a cell phone handy with which to phone the station.
4. Have a web browser handy to lookup the phone number:
http://www.wypr.org/contact-us
5. Be sufficiently experienced with such problems to be able to
explain the problem to the low technical level person who answers the
phone, and at a high level should someone be available that
understands the problem.
6. Be able to explain why the various OTA station monitors show that
everything is just fine and both transmitters are on the air.
7. Be able to explain why so few other people have called in the
problem. I've found that stations do not act on such things unless
there are a large number of calls, or they get a call from a sponsor.

William of Occam suggested that we eschew needless complexity.


He was wrong. Todays fashion is to target one's writing to the lowest
level of intelligence and expertise that one might expect the document
to be read. If someone is writing for a engineers with FM broadcast
experience, it would look very different if they were writing for the
GUM (great unwashed masses). The best advice I've seen is to write
for those that are competent in their field of expertise, not
necessarily in yours.

In this case, the problem isn't very complicated to understand if one
has some experience with FM capture effect, simulcast techniques, FM
simulcast, repeaters, translators, FCC FM 60dBu contours, digital vs
analog FM receivers, and possibly how HD Radio works.

I didn't mention the possible HD RADIO problem because I thought it
was unlikely. Yet the symptoms are similar. WYPR broadcasts on 88.1
(main FM channel), 88.1-1 (HD1 news and talk), 88.1-2 (HD2 BBC world
news), and 88.1-3 (HD3 classical music). During commercial breaks and
other interruptions, stations sometime fill in the dead air with audio
from one of the digital sub-channels. There is a delay between the
main analog FM audio and the delayed digital version, in this case on
HD1. Stations with this arrangement usually have some way to adjust
this delay so that switching between the analog audio and HD1 does not
result in an obvious delay. If the listener is in a moving vehicle,
and has the radio switched to HD1, the signal will drop out on HD1 in
fringe areas causing the receiver to revert back to the main FM audio.
This is particularly irritating because many HD Radio receivers do not
have a setting that forces the receiver to stay on HD1 and not switch
to the main analog channel. It's possible that this might have been
the problem, but I can't tell from here without more details.

So, what have we learned here?
1. Simple explanations are fine for the GUM but not so useful if you
want to understand what had happened and how it works.
2. If you want to understand something, you have to dig deep, really
deep.
3. RF is magic.
4. Nothing is simple.
5. If something seems too complicated, ask questions or Google for
understanding. Don't just complain that it's too complexicated.

Peter Wieck
Melrose Park, PA

--
Jeff Liebermann
150 Felker St #D
http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558


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Default Two rsignals at same time, 88.1 where

On Wednesday, August 1, 2018 at 11:27:52 AM UTC-4, Jeff Liebermann wrote:
On Wed, 1 Aug 2018 05:13:48 -0700 (PDT), "
wrote:

Y'all are making this far too complicated and inventing explanations other
than a simple sync issue within the station itself. Could be as simple as
a tech replacing a piece of equipment and dropping a jumper into the
wrong jack. 10 minutes later - after the phones started ringing off
the hook - it got fixed.


I doubt if more than few listeners heard the problem.


Or, every listener did, as the problem was within the station and not due to some wild concatenation of unusual forces. The entire premise of a complicated answer requiring vast research is that it ain't necessarily so.

What I am suggesting is that an acorn falling from a tree does not require the sky to be falling, Chicken Little notwithstanding. Sometimes, it is simply (and merely) an acorn.

Peter Wieck
Melrose Park, PA

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Default Two rsignals at same time, 88.1 where

On Wed, 1 Aug 2018 09:28:04 -0700 (PDT), "
wrote:

On Wednesday, August 1, 2018 at 11:27:52 AM UTC-4, Jeff Liebermann wrote:
On Wed, 1 Aug 2018 05:13:48 -0700 (PDT), "
wrote:

Y'all are making this far too complicated and inventing explanations other
than a simple sync issue within the station itself. Could be as simple as
a tech replacing a piece of equipment and dropping a jumper into the
wrong jack. 10 minutes later - after the phones started ringing off
the hook - it got fixed.


I doubt if more than few listeners heard the problem.


Or, every listener did, as the problem was within the station and not
due to some wild concatenation of unusual forces. The entire premise
of a complicated answer requiring vast research is that it ain't
necessarily so.


You really should read past the first line of my previous posting.
Included are a list of conditions necessary for a listener to actually
hear the problem and to produce a sane a report. The first item on
the list is that the listener must be:
Roughly equal distant from both stations or in an area where
the signal strengths are about the same.

If the signals from both stations on 88.1 were NOT within 2dB, capture
effect would cause one FM station to "capture" the other. All a
listener would hear is the strongest station. Therefore, the only
locations where listeners might have their receivers switch back and
forth between the two stations would be in locations roughly equal
distant from both stations. That represents a fairly small percentage
of the service area and prospective listeners for both stations.

Do you have a problem with this, or do you prefer to continue
suggesting that there is a simpler explanation, which incidentally you
didn't bother providing?

Incidentally, please note that the OP met all the requirements on my
list, yet didn't call the station to report a problem. This should
offer a clue as to how many listeners called the station.

What I am suggesting is that an acorn falling from a tree does
not require the sky to be falling, Chicken Little notwithstanding.
Sometimes, it is simply (and merely) an acorn.


Quite profound, but since a falling acorn makes no sound when nobody
is listening, it doesn't matter.

Peter Wieck
Melrose Park, PA

--
Jeff Liebermann
150 Felker St #D
http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
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Default Two rsignals at same time, 88.1 where

On Wednesday, August 1, 2018 at 6:20:46 PM UTC-4, Jeff Liebermann wrote:

Incidentally, please note that the OP met all the requirements on my
list, yet didn't call the station to report a problem. This should
offer a clue as to how many listeners called the station.


He was in his car - I do not initiate calls when driving, even hands-free, voice-activated calls. I will take calls (very briefly) on rare occasion when I know the caller and know the call is actually immediately important - and then I will pull over. And I will certainly NOT go through searching for a number while driving.

Come on!

Peter Wieck
Melrose Park, PA
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Default Two rsignals at same time, 88.1 where

On Tue, 31 Jul 2018 04:02:46 -0400, micky wrote:

Satruday, july 28, at 10:50AM I was driving through Westminster Md,
listening to 88.1 FM, Baltimore,and I was getting two copies of the same
sounds, one a second or so delayed compared to the other.

This went on for at least 5 miles, at least 10 minutes.

It was nearly impossible to tell what was being said.

How could this happen?

It's a rural area with no very tall buildings and even if there were a
reflection, it would not reflect at me everywhere along a 5 mile line.

I've been there many times before, usually listening to the same
station, and it never happened before. So I don't think there is a
second station on the same frequency in radio range.


Could it be that the transmitter itself was sending out two copies of
the sound, one second apart?


After about 10 minutes, it stopped and the sound was good again.


Well, a one second delay is not possible on the earth - the signal path
would have to be about 500,000 miles.

What I think it could be is two stations running the same program
material (LOTS of stations operate at least part of the day from common
network feeds) and there was a slight delay between the feeds they were
getting. (Most of this network stuff is now handled over the internet.)
But, usually, stations relatively nearby do not operate on the same
frequency.

One other possibility is that somebody at the station goofed and started
TWO instances of the network streaming application, and they were getting
slightly out-of-time buffers. I have done this many times when listening
to material on the internet. The 10 minutes of this might be how long it
took for a nearly listener to get through and report the problem. Or,
the local manager only checks the broadcast every so many minutes to make
sure they are still on the air.

Jon
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Default Two rsignals at same time, 88.1 where

On Tue, 31 Jul 2018 11:37:25 -0700, Dave Platt wrote:


And... aha! Baltimore 88.1 is WYPR, and according to Wikipedia, they
have a simulcast transmitter on the same frequency operating as WYPF in
the Frederick/Hagerstown area. Westminster is just about equidistant
from Frederick and Baltimore. WYPF's transmitter is in the forest just
north of Frederick, while WYPR's is near Druid Hill Park is Baltimore.


Looks like you got it. MOST unusual to have the "sister station" on the
SAME frequency as the main one. We have an NPR affiliate here with 4
sister stations. But, all of them are on different frequencies.

Jon


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Default Two rsignals at same time, 88.1 where

On Thu, 2 Aug 2018 04:15:18 -0700 (PDT), "
wrote:

On Wednesday, August 1, 2018 at 6:20:46 PM UTC-4, Jeff Liebermann wrote:

Incidentally, please note that the OP met all the requirements on my
list, yet didn't call the station to report a problem. This should
offer a clue as to how many listeners called the station.


He was in his car - I do not initiate calls when driving, even hands-free,
voice-activated calls. I will take calls (very briefly) on rare occasion
when I know the caller and know the call is actually immediately important
- and then I will pull over. And I will certainly NOT go through searching
for a number while driving.

Come on!


I really didn't think it was necessary to lecture on how to safely
place a call from inside an automobile. I rather assume that most
drivers are familiar with the local laws concerning yacking while
driving and understand that distracted driving is a really bad idea.

Out of all the points I made on analyzing possible causes for what had
happened, you pick what I would consider a minor point or curiosity
item at best. I do wish you wouldn't do that. However, since you
want to switch topic from how FM modulation works to mobile phone
etiquette, I'll play along, especially since you reinforced my point
about nobody calling the station.

Only moving drivers, equidistant from both stations on 88.1MHz, would
have heard the problem. Since these drivers are unlikely to call the
station while moving, I consider it even less likely that they would
have bothered to make the call after parking the car, because the
problem would no longer be heard while stopped. They would probably
suspect that the problem was "fixed" by the station and that it was no
longer necessary to call the station.



--
Jeff Liebermann
150 Felker St #D
http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
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Default Two rsignals at same time, 88.1 where

Y'all are making this far too complicated and inventing explanations other than a simple sync issue within the station itself. Could be as simple as a tech replacing a piece of equipment and dropping a jumper into the wrong jack. 10 minutes later - after the phones started ringing off the hook - it got fixed.

Offered before.

a) Does not require any special equidistant spacing.
b) Does not require a 90,000 mile bounce.
c) Requires no coincidences.
d) Explains what occurred.
e) And is as likely as any other explanation.
f) And you neatly sidestepped why a *driver* would not make such a call.
g) While also ignoring the fact that the OP might simply not care about calling at all - and just asked a simple question.

Sheesh!

Peter Wieck
Melrose Park, PA
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