InterceptRadio.com Forums

After some software updates, I'm able to automatically record audio from unknown talkgroups. However, it's occurred to me that my original idea of handing out .MP3s for community interpretation may not be permissible under the Communications Act of 1934. Doing so could be viewed as "disclosure" of a non-"broadcast" signal, and given the evident legal climate we're operating in, I'm not interested in starting a one-man crusade.

In any event, it may not be necessary -- I'm just not seeing that many undocumented groups pop up. Nothing new was logged all afternoon (May 1) during the protest activity downtown, which was a bit of a surprise.

I will be editing this message on an ongoing basis when/if additional audio from unknown groups becomes available for analysis.

Logged on 868.175 control channel

60016 (0xEA70) Bus-tunnel construction
59984 (0xEA50) Bus-tunnel construction traffic control
29600 (0x73A0) I-Call traffic related to radio shop activity (see earlier thread)
24912 (0x6150) Safeco Field security

Observed but not yet recognized

63504 (0xF810) "White Center office to playground" repeated several times, no reply
62384 (0xF3B0) Appears to be related to SFD training activity
27248 (0x6A70) Several brief transmissions of dead air
8144 (0x1FD0) Data traffic (commonly-used data talkgroup, user unknown)
7632 (0x1DD0) Traffic related to opening/closing gates at unknown facility
5872 (0x16F0) Appears to be used for radio-test traffic only

Logged on 868.775 (EPSCA) control channel

16432 (0x4030) Eastside FD training/drill activity
17008 (0x4270) Overlake Hospital

Observed but not yet recognized

16240 (0x3F70) Several brief transmissions of dead air (Bellevue Community College?)
25888 (0x6520) Radio shop?

Hey John - thanks for doing this! It sure sounds like a fun project. And I am very impressed by your setup that allows you to do it, too!

Don't get discouraged if you don't get anything right away - if you think about it, the takgroups we don't have are probably the ones seldom used as well (but could nevertheless be quite interesting when used). So it may take some time. But cool project! Keep us updated...

Yeah, the main drawback with this approach is that the really interesting talkgroups probably won't be used except in unusual circumstances, like the one marked "used during WTO" in the current list. Without another WTO-scale event, or some glasnost from the management folks, many of the gaps in the list will remain unfilled.

Not sure what you are using John but I have found this works great .

http://bellsouthpwp.net/k/d/kd5eis/IDTr ... racker.htm

John, I want to THANK you.
It's great that someone out there is attempting to refresh the stale KC/EPSCA/Valleycom talkgroups. I've noticed for awhile now that some talkgroups have been popping up that are not documented anywhere.
Who knows?? You might have inspired others to start logging TG's(myself included)
Thanks Again

You're welcome -- hope this helps. It does appear that our existing talkgroup list is still 99% good. After a few weeks of continuous monitoring, I have seen very little activity on undocumented groups.

The list at the top of the thread is current as of 5/16. I'm going to switch the logging client from the King County control channel to EPSCA for a few weeks. I don't expect to hear much new there, either.

The best way to help is to monitor the groups in the "Observed but not yet recognized" category for any clues that will help identify them. Post any exciting revelations to this thread, and I'll update the first message accordingly...

Huh, well that sure is interesting... yeah, maybe we do have them down pretty good? I'de still have to imagine there the few we don't have that just arn't used very much.

Definitly the three biggies are the Seattle, EPSCA and KC Simulcast. It would be interesting to see if you got any unknown hits off some of the intellirepeater sites, such as
KC Courthouse 867.9125
Apple Cove 868.65
EPSCA North 868.95
Grass Mtn 858.4875
McDonald Mtn 860.7125
Or even Dodge Ridge (857.4625) but you pretty much have to be on the pass to recieve that.
Not sure if you're even able to recieve all those from where you monitor? From my office I can get every site except Dodge and Sobieski. I often find it fascinating which talkgroups you see active on IR sites (example - SPD East was on Apple Cove the other day... Why? Who knows, I guess someone with thier radio on that channel must have been near there!)

I'll watch out for those talkgroups you mentioned - thanks again for doing this! Very cool project.

Unfortunately I'm stuck with poor (indoor) antennas in a fairly-dead spot (downtown Kirkland, near ground level). None of those other control channels yields a usable S/N ratio on either my homebrew receiver at the office or the commercial RX at home. So for now at least, I'm constrained to the 868.175/868.775 channels.

Does anyone know what TG 48768 is ??? Sounds like a Police / Fire IC Channel. MTM

I recorded a hit from 48528 (0xBD98) yesterday at around noon, but no audio was logged, so it was probably a data error. Nothing from 48768 at all. What control channel was this on?

I've updated the first message with the results of 3 weeks' additional monitoring of EPSCA between 5/17 and 6/08.

Conclusion: our existing talkgroup list is actually in pretty good shape, despite being several years old. Would any admins care to update it with the (few) results above?

TG 16240 might be Bellevue Community College.

Thanks; I updated the list with the possible BCC entry. Let me know if you become reasonably certain of that one...

The frequency/talkgroup database has now been updated, but for some reason the new entries are showing up at the very end of the list rather than in order of their talkgroup IDs.

John, do you have a hit for 23955? I've heard on both Seattle and EPSCA -- it looks to be the main dispatch for the KC Trans Police -- at least that's what I'm guessing.

Don't forget that you have to zero out the least-significant hex nibble in any talkgroup ID. 23955 is 0x5d93, which, when you drop the '3', turns into 0x5d90 (23952).

That's listed as "KC Trans Pol Metro 1" in the database, so it looks like your guess was correct.