Trying to locate channel used by Takoma Park PD SAT

villlythekid

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I am looking for a channel that the Takoma Park Police Department is using for their SAT. (Special Assignment Team) They just started up the SAT and were using channel W9, but recently that channel has gone quiet. I have channels A12, B12, W9, and W10 scanning on my BCD996p2, but it seems as if there is another undiscovered channel they are using, or they have recently encrypted the W9/W10 Tactical channels as Gaithersburg PD has. If I remember correctly, they refer to it as "K10 or King 10," and I overheard them talking about how some police cars don't have access to that channel yet (so I assume it is a new channel.) If anyone has any information, please let me know.
 

maus92

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They may also use a talkaround simplex channel for their tactical ops, and I wouldn't be surprised if it is encrypted - but we are talking about the PRTP.
 

maus92

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Those have been quiet ever since I put them in on August 12th, and today they referred to the channel as "10." Thanks for the help though.
Have you considered running Unitrunker to follow the channel grants? You could probably figure out what tg they are using if they are not using a talkaround channel. "10" sounds like a knob position.
 

villlythekid

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Have you considered running Unitrunker to follow the channel grants? You could probably figure out what tg they are using if they are not using a talkaround channel. "10" sounds like a knob position.
I haven't heard of such a program, I'll try it out. I can't seem to find the download link- if that's what it is. They refer to the either then main channel or TP 2 as 7- would that also follow the knob position?
 

villlythekid

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I haven't heard of such a program, I'll try it out. I can't seem to find the download link- if that's what it is. They refer to the either then main channel or TP 2 as 7- would that also follow the knob position?
And I just asked the Takoma Park Police sergeant who leads the SAT- he said the channel is encrypted. So I'm assuming that means there's no way of listening to it, correct?
 

maus92

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I haven't heard of such a program, I'll try it out. I can't seem to find the download link- if that's what it is. They refer to the either then main channel or TP 2 as 7- would that also follow the knob position?
Maybe. No way of knowing for sure without seeing a police zone / channel plan. You're probably going to have to deduce it on your own - and note that it will likely change by the end of the year.

Here is the product page. Unitrunker The floppy disk icon in the upper right has the download links. If it were me, I'd buy an RTL-SDR dongle for $25 to dedicate to the program. Follow the Software Defined Radio link in the lower right corner. There are old threads / resources in this forum that explains how to set it up, as well as the product page. There is a learning curve, but it's not all that hard to do.
 

wtp

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just remember that most users of any radio system know very little to nothing about it.
a detective in my county told me i can't hear the narcs, they are on a different system, as i was listening to them.
i just agreed so as to not make him look bad.
 

villlythekid

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Maybe. No way of knowing for sure without seeing a police zone / channel plan. You're probably going to have to deduce it on your own - and note that it will likely change by the end of the year.

Here is the product page. Unitrunker The floppy disk icon in the upper right has the download links. If it were me, I'd buy an RTL-SDR dongle for $25 to dedicate to the program. Follow the Software Defined Radio link in the lower right corner. There are old threads / resources in this forum that explains how to set it up, as well as the product page. There is a learning curve, but it's not all that hard to do.
I'm back again. What do the digits/letters refer to? (A12 is dispatch, B12 is Ops, K10 is SAT) I have the zone plan right here: Montgomery County Zone Plan but it skips over the letter "K."
 

dpcain

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Letters are typically zone indicators, and numbers are 1-16 for the 16 channel positions in most radios.

Some places (like Anne Arundel which has a very comprehensive master zone layout that avoids zone number/name duplication) reverse that and number their zones, using A-P to describe the 16 channel positions (e.g. 11H is the 8th channel in Zone 11) but most places do alphanumeric zones.
 

maus92

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I'm not sure how accurate that channel / zone plan is - looks pretty old. I know the fire radio programming more complex. MC has lots of zones and channels. The channel designations can be a combo of zones (many,) and knob positions (16.) A concentric a-b-c switch is commonly configured to select the first 3 zones. In reality, the digits and letters should not matter to scanner or sdr user - only the tgs are important.

It *seems* like MC radios are programmed something like this:

The number refers to the knob position of the channel selector (1-16);
The letter refers to the zone (A-xxx) selectable by the a-b-c switch or a scroll function;
The a-b-c switch selects the first 3 zones: A, B, or C.

Thus if you are a Takoma Park LEO, your radio would normally be set to Zone A using the a-b-c switch set to A position, and channel knob position 12. If you wanted to switch to the ops channel, you turn the a-b-c switch to the B position, leaving the channel selector on 12.

To get to the K zone, you would use whatever scroll tech is installed in the radio. Not sure why SAT would be in the K10 zone and channel - that doesn't follow the channel plan logic.
 
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villlythekid

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I'm not sure how accurate that channel / zone plan is - looks pretty old. I know the fire radio programming more complex. MC has lots of zones and channels. The channel designations can be a combo of zones (many,) and knob positions (16.) A concentric a-b-c switch is commonly configured to select the first 3 zones. In reality, the digits and letters should not matter to scanner or sdr user - only the tgs are important.

It *seems* like MC radios are programmed something like this:

The number refers to the knob position of the channel selector (1-16);
The letter refers to the zone (A-xxx) selectable by the a-b-c switch or a scroll function;
The a-b-c switch selects the first 3 zones: A, B, or C.

Thus if you are a Takoma Park LEO, your radio would normally be set to Zone A using the a-b-c switch set to A position, and channel knob position 12. If you wanted to switch to the ops channel, you turn the a-b-c switch to the B position, leaving the channel selector on 12.

To get to the K zone, you would use whatever scroll tech is installed in the radio. Not sure why SAT would be in the K10 zone and channel - that doesn't follow the channel plan logic.
Thanks for that information, that is interesting why they would go from A and B to K. I know that you're from Annapolis and not Montgomery County, but do people every once in a while try to find some of the undiscovered talkgroups? (since it's a county of 1.1 million) I'm just not ready to put in the time, effort, and money to find this one channel. Would it eventually pop up the RR Montgomery County Trunking System page if discovered?
 
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maus92

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Thanks for that information, that is interesting why they would go from A and B to K. I know that you're from Annapolis and not Montgomery County, but do people every once in a while try to find some of the undiscovered talkgroups? (since it's a county of 1.1 million) I'm just not ready to put in the time, effort, and money to find this one channel. Would it eventually pop up the RR Montgomery County Trunking System page if discovered?
It's likely that channels / tgs were added after they system was first deployed. It's almost moot now that the county is going to a new system in a few months, and the Zone / Channel plan could change radically. The PRTP Police may also be using RINS or 8TAC channels that are not part of the TRS, but would still be referred to by a zone letter and channel number.

As far as finding "undiscovered" tgs, you would need control channel decoding software as I mentioned previously. I run it occasionally on the MC system when I'm in the area, but to really analyze a system, it takes hours of listening / recording.
 

villlythekid

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It's likely that channels / tgs were added after they system was first deployed. It's almost moot now that the county is going to a new system in a few months, and the Zone / Channel plan could change radically. The PRTP Police may also be using RINS or 8TAC channels that are not part of the TRS, but would still be referred to by a zone letter and channel number.

As far as finding "undiscovered" tgs, you would need control channel decoding software as I mentioned previously. I run it occasionally on the MC system when I'm in the area, but to really analyze a system, it takes hours of listening / recording.
Ok. I've heard a little about that new system, do you have any info or any links to more info? The only thing I heard a few months ago is that it might go encrypted, but since then I haven't had any more info.
 

maus92

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I do not, but my suggestion to set up control channel tracking software would help map the new system once it goes on the air. It will be using the same frequency set, but a more modern control technology and waveform.
 
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