digital signal on 146.50?

[Barry Hansen]

What is the digital burst signal on 146.500 around Seattle? Anyone else notice this?

 

There is a loud non-voice transmitter in the FM simplex portion around 20-30 kHz below the national calling frequency. It’s very strong for me near Issaquah and I have reports it’s quite loud in Redmond. It’s reportedly strong across the Puget Sound region.

 

The signal appears to have a carrier on 146.49 with a digital part on 146.50. It occurs at completely random times and durations. It sounds something like the staticy burst of APRS at 9600 but lasts longer with a variable duration of a few seconds up to 30 seconds. Nothing intelligible to the human ear can be heard. I first heard this in early November, most often in mornings (but then I listen most often in mornings). It seems less frequent now; it used to occur a couple times a minute, but I only heard it once this morning. I live near Issaquah and, directionally, it appears to come from a bearing of 240 degrees on a line from SeaTac.

 

Just curious. Thanks and happy holidays,

Barry K7BWH

ba...@k7bwh.com 

 

 

[Paul Drahn]

Does the FCC still have an office and engineers in Kirkland? IF so, ask them about the mystery.

QSO with someone on 146.500 and see if it has any effect on the mystery signal.

I used to live near Pine lake. Before there was a Sammamish City.

Paul, KD7HB

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[Barry Hansen]

An update on the digital mystery signal, thanks to replies from helpful hams:

 

Apparently the WWARA www.wwara.org has picked a local band plan that includes digital repeater outputs in the FM simplex portion that borders on the 2m national calling frequency:

“146.40625 - 146.50625 VNBD Repeater Outputs

WWARA coordination recommended

146.4125, bottom center frequency

12.5 kHz steps, 8 channels to 146.5000, + 1 MHz offset

VNBD, UNBD only”

 

https://www.wwara.org/WWARA_BAND_PLAN_2012_07_08.pdf  

 

And apparently we’re hearing one of the first such transmitters; it’s probably a DSTAR signal.

[Jim Aguirre]

"We have met the enemy and they is us!" - Pogo

Sent from my iPad

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[Gary Lewis]

Hi Barry

Mike from Technical Support at ICOM called me back and after monitoring 146.50 for awhile today.

Mike heard the unknown signal and has concluded that it is not a DSTAR signal. That its transmissions do not fit the sound and pattern familiar to a DSTAR signal and he is not sure just exactly what it is. Mike did wish us luck in finding it, and suggested that it might be a "Wired Data Terminal" somehow getting out on 146.50.

Gary WA7BBJ

--

[Kim]

This message thread reminded me of the "olden days" of the "Fox Hunt"
several people with a home-brew direction finders triangulating the signal
source while mobile and narrowing it down..
Would that work in this instance ?.
Sometimes the Hams need to do the work of the FCC, eh ?
Happy Hunting,
Kim  K7DGI
Lower Hood Canal

[K7VE]

It is a D-STAR repeater -- http://dstarusers.org/viewrepeater.php?system=KF7CLD  It has been operating for several months but due to a misunderstanding was operating a reverse pair, coming out 147.50 and switch to 146.50 output a couple of weeks back. This is according to the WWARA band plan adopted in June.

Repeater operation is permitted on 2 meters in the segments,  144.5-145.5 and 146-148, so it is an operation within the regulations and within the voted band plan under WWARA.  You will see narrow band, mostly digital repeaters, between 146.40 - 146.50 / 147.40 - 147.50  (Mostly high in / low out, with a few exceptions).

There are also ULTRA-NARROWBAND (6.25 KHz) pairs at 146.05 + 600 khz and 147.395 - 600 khz

Repeater operation is not permitted 144.0 - 144.5 or 145.5 - 146.0 

[Barry Hansen]

Thanks John!

I encourage everyone to read about and participate your local band planning associations, such as WWARA (www.wwara.org), because they coordinate activity in the FM simplex regions as well as the traditional repeater frequencies. They do listen and want you involved.

 

Barry K7BWH

ba...@k7bwh.com 

 

From: pnw...@googlegroups.com [mailto:pnw...@googlegroups.com] On Behalf Of K7VE
Sent: Saturday, December 22, 2012 12:21 PM
To: pnw...@googlegroups.com
Subject: [PNWVHFS] Re: digital signal on 146.50?

 

It is a D-STAR repeater -- http://dstarusers.org/viewrepeater.php?system=KF7CLD  It has been operating for several months but due to a misunderstanding was operating a reverse pair, coming out 147.50 and switch to 146.50 output a couple of weeks back. This is according to the WWARA band plan adopted in June.

 

Repeater operation is permitted on 2 meters in the segments,  144.5-145.5 and 146-148, so it is an operation within the regulations and within the voted band plan under WWARA.  You will see narrow band, mostly digital repeaters, between 146.40 - 146.50 / 147.40 - 147.50  (Mostly high in / low out, with a few exceptions).

 

There are also ULTRA-NARROWBAND (6.25 KHz) pairs at 146.05 + 600 khz and 147.395 - 600 khz

 

Repeater operation is not permitted 144.0 - 144.5 or 145.5 - 146.0 

[Edward R Cole]

Hmm, makes me wonder how wide D-STAR signals are?  Output carrier is only 20-KHz below the national FM calling freq.  Make me glad to be 2400mi away.

73, Ed - KL7UW

[Stephen Kangas]

WWARA has been planning changes and expansion of 2m and 70cm repeater allocations for some time now, but they have not done a good job of informing & involving simplex, weak signal, and other users of those band areas coveted by them.  I had suggested additional communications means for them to reach other hams who are not repeater owners, but they failed to follow up on those means.  Interference with other traditional uses of certain band areas will likely continue to grow as a result.  Barry’s point should also be heeded, however, as this incident can be considered a warning shot across the bow, meaning it behooves those concerned about such WWARA actions to take more proactive actions in monitoring/participating/protesting them as appropriate, even as they choose not to reach out to you more proactively.  Ie, it helps everyone to construct a 2-way street of communication, and it’s become obvious to me & some others that this will need to be initiated outside of WWARA.

 

Stephen W9SK

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[Scott Honaker]

It is an ultra-narrowband signal at 6.25kHz bandwidth.  That means am FM signal is far more likely to interfere with the DSTAR user than the other way around.  It will provide more protection for the national calling channel than the previous FM channel.

Scott N7SS

[Scott Honaker]

For several tears it has been the stated goal of WWARA to accommodate newer, more spectrally efficient modes.  We have discussed options endlessly and done nothing.  This June someone proposed taking a few "simplex channels" on 2m and convert them to a new narrowband-only repeater subband.  This was done without touching any weak signal, satellite, digital spectrum or the national calling channel..  Since FM simplex users can occupy ANY of the FM spectrum on a non-interference basis, it seemed using some of this spectrum would have the least impact.  

The changes were published to the WWARA members immediately after the meeting, The new band plan was posted to the web site and another message was sent to all ARES staff via the SEC and all WWA ARRL members via the Section Manager.  We were unaware of another way to reach WWA hams.  This (and other reflectors) weren't used because no weak signal spectrum was effected and they have members well outside WWA.

I still expected someone to appear at the September meeting to challenge the decision.  December also came and went without a challenge.  I have seen comments various places but it's either a workable solution or no one cares enough to identify an alternative.

The June meeting was lightly attended and I was uncomfortable making a decision with so little participation but it had also been dragging on for quite a while.  As the saying goes, decisions are made by those that show up.

Scott N7SS

[Bill Vodall]

> I encourage everyone to read about and participate your local band planning
> associations, such as WWARA (www.wwara.org), because they coordinate
> activity in the FM simplex regions as well as the traditional repeater
> frequencies.

I don't believe that is accurate. All the "repeater coordination"
groups can really coordinate is repeaters and then only between other
repeaters. Outside of a small number of FCC mandated rules - most of
the operating allocations of the local bandplan is built on common
courtesy..

Up until this past summer the WWARA had done a remarkable job of
organizing for all involved... Now I believe they've tipped the
scales towards the repeater owners but unfortunately there's such
little activity anywhere on two meters these days it doesn't make much
difference...

> decisions are made by those that show up...

The first step forward should be online virtual meetings and get
beyond this old way of doing business...

73
Bill - WA7NWP

[Barry Hansen]

The WWARA by-laws and policies are nicely written on www.wwara.org, so for
technical accuracy I hope people read and understand how it works in western
Washington.

Although people can parse words and dance around the syntax, the bottom line
is that WWARA has coordinated repeaters onto frequencies traditionally used
by FM simplex users. Therefore, the activity is something more than
"repeater coordination". Imho, the term is a misleading head fake that
allows simplex operators to assume they're safe and unaffected, which
unfortunately is not recently true.

I don't want to argue vocabulary and semantics; I want more people involved
in their local "repeater coordination" group so there is a more balanced
representation of affected users.

I see there was lively and thoughtful discussion on the WWARA email
reflector in June and July this year. The reflector archives are public. An
interesting place to start exploring these threads is message 602 here:
http://groups.yahoo.com/group/WWARA-Members/message/602 Bill, I notice that
you participated, which is awesome, thanks, let's hope more people read it.

> there's such little activity anywhere on two meters these days it doesn't
make much difference...

I noticed your informal survey in 2010 (mentioned on the WWARA reflector in
message #441, tyvm) and agree with your observations. The conventional
wisdom seems to be that usage is lower, but on the air I keep coming across
pockets of simplex activity. It's not hard to find.

73 Barry K7BWH
ba...@k7bwh.com

-----Original Message-----
From: pnw...@googlegroups.com [mailto:pnw...@googlegroups.com] On Behalf

Of Bill Vodall
Sent: Saturday, December 22, 2012 7:38 PM
To: pnw...@googlegroups.com
Subject: Re: [PNWVHFS] Re: digital signal on 146.50?

> I encourage everyone to read about and participate in your local band

[Paul Drahn]

Barry.
As an observer of this discussion with no immediate impact from the
WWARA, I have a question that may or may not be important, but will ask
anyway.

Do the repeaters listen for simplex activity on the output frequency
before they transmit?

73, Paul, KD7HB