King County

[AtomicTaco]

Zard0z--are you hearing this or this?

 

[Zard0z]

sounds more like the second link. But a little longer and about two of three in a row then nothing for awhile
except voice traffic.... then it squawks again.......... It is however not exactly what i am hearing. Can you monitor
CH 3? It is pretty common and you should hear it after a short while. I must admit I hear it better closer to seattle
than out here.

 

[AtomicTaco]

Do you live really close to a street with bus traffic? I think you're getting bleed from the data channel input.

 

[Zard0z]

not it. I have portable scanner and car antenna and I hear it in all three places at different times. I did
not hear it latey(tonight) But I will for sure tommorrow when I listen and travel to and from seattle.

Too bad I cant record on mobile but will try to cath it at home.

I will try to remember times and such etc. I have listened for almost six months now at least
a bit every day for Metro channels. As well as SPD APD WSP RPD and the Sherriff's Dept.
That is quite a lot. I use it to path my way around and keep in touch with what is going on close to me.
It is quite fun to learn how and what they are doing.

 

[Stavro35]

Is the new system 800mhz or 700mhz ? Is it digital or analog? Unless I'm not looking in the right place. I don't see a listing for it.

 

[AtomicTaco]

Metro's new system will be digital TDMA 700 MHz. It hasn't been fully built out yet and won't be put in to use until 2011 or later.

 

[Stavro35]

O.k so it's not listed in the database yet?

 

[Zard0z]

Atomic Taco I have a recording of it here > https://www.yousendit.com/transfer.php?action=download&ufid=U0d5b3BMTER0QTJGa1E9PQ

On ch 3. It is a amr file and quicktime should play it for you.

the tone is there but hard to hear this far away...........

 

[AtomicTaco]

O.k so it's not listed in the database yet?

No, but you can check out licenses WQHJ934 and WQHJ935.

Atomic Taco I have a recording of it here > https://www.yousendit.com/transfer.php?action=download&ufid=U0d5b3BMTER0QTJGa1E9PQ

On ch 3. It is a amr file and quicktime should play it for you.

the tone is there but hard to hear this far away...........

I have no idea. Very weird. Intermod, maybe? But then again you said you're mobile...

 

[AtomicTaco]

Digging through some RFPs:

"How are routes assigned to radio channels?"
"In the current Radio/AVL system, routes are grouped by geographic area and assigned to a particular radio channel. For example, trolley routes are on one channel while south King County routes are assigned to another channel."

"What is the frequency of the vehicle stats updates provided by the current CAD/AVL system polling function?"
"Approximately 10 coaches per second using two data channels, or about every 1.5 minutes during peak service."

And now the piece that makes me happy after the stress of 2 midterms today.
"The Transit radio system uses eight 450 MHz radio channels: four vehicle voice channels, two
vehicle data channels, two service supervisor channels, and two 800 MHz channels utilized by
Power and Facilities staff. The following is an update of the channel configuration table found in
the King County Radio Comprehensive Plan, April 1998."

Note that RV is Revenue Vehicle, not Recreational vehicle. Not that it wouldn't be fun to take one on a camping trip.

4 and 7 are swapped. Keep in mind it's data from 1998.


"DACS time is synchronized to WWVB or to an Internet time standard and it sends time syncs every 30 minutes to the fleet on the data channels."
So that means you're not hearing a time data burst on the voice channels.

Here's the whole doc in case you want to read it.

 

[Zard0z]

Very nice! Great work there and thanks for the doc.

I have a better recording of CH3 for you te hear. This is caught on my mobile on the freeway
so there is some noice too but a much better example than my base station.

Like I said this only happens on CH3.

Here is the link >https://www.yousendit.com/transfer.php?action=download&ufid=U0d6eEVVdGo4NVVLSkE9PQ

link is only good till 5/27

 

[AtomicTaco]

Sounds like you're getting the unit ID. I don't hear it unless I'm listening on the input. If it is what I think it is, it's basically the same thing as a MDC-1200 pre-ID.

 

[Zard0z]

Great!!

That what it has to be... I bet it is selective calling.

You said hear it on the input??!! Where else do you hear ch 3 except for 453.3750???

thanks for your input.

 

[AtomicTaco]

458.375

 

[Stavro35]

Are they digital what are the frequencies?

 

[AtomicTaco]

Are they digital what are the frequencies?

Current ops are analog non-trunked.

Freqs are here and in the table above.