Batboard

I want to monitor 5 specific TG's for the New Jersey State Police. From what I understand, the NJSP is an 800Mhz Type II analog system. (860.9375 - 855.2125 Mhz)

28304 HERN1 Statewide alert
28336 HERN5 Statewide ops
28432 HERN6 TAC 1 North
28464 HERN7 TAC 2 North
57712 EAS1 Alerting Channel

Can I do this with a Motorola Astro Mobile, and have it follow without the radio affiliating? - I don't want this thing to transmit & would consider hardware mods to disable the PA. If there's a different/better radio choice, i'm open to suggestions.

FWIW, I tried using a borrowed Bearcat 898T, but every time I would transmit with the Syntor, the scanner would lockup.

Martin

spareparts wrote:I want to monitor 5 specific TG's for the New Jersey State Police. From what I understand, the NJSP is an 800Mhz Type II analog system. (860.9375 - 855.2125 Mhz)

28304 HERN1 Statewide alert
28336 HERN5 Statewide ops
28432 HERN6 TAC 1 North
28464 HERN7 TAC 2 North
57712 EAS1 Alerting Channel

Can I do this with a Motorola Astro Mobile, and have it follow without the radio affiliating? - I don't want this thing to transmit & would consider hardware mods to disable the PA. If there's a different/better radio choice, i'm open to suggestions.

FWIW, I tried using a borrowed Bearcat 898T, but every time I would transmit with the Syntor, the scanner would lockup.

Martin

Sure you can:

A) It must be flashed for trunking

B) You must have the system key (good luck!)

C) You must search the board to figure out how to do this. It has been discussed at extremly great lenghts here, and it should not be hard to track down the information.

-Alex

You will also need to know the control channel(s) in use and the trunking format type ("message", "transmission" or "PTT-ID") and SysID (if you have a SysKey, you'll have the SysID).

As Alex implies, the hurdles can be high. A scanner is often a more practical choice; I don't know anything about the "898T", but a R/S Pro-96 should work just fine

Here is some of the information that you are looking for.

Dennis

http://www.radioreference.com/modules.p ... RR&aid=753

I'm suprised that RKG didn't jump in there and say you also have to convert those talkgroups to Hex.

Assumed as much. But you're right.

Spareparts, if you get one of the APCO 25 scanners you can monitor specific talk groups with no problem. Plus, you don't have to even program in all the system channels, just the control channel(s).

Well, here's the answer: I tried several different RS scanners. All exhibited a problem when either the VHF SyntorX or the UHF X9000 transmitted. Basic RF overload.

I also had doubts about the 2 syntors, considering their age, so I had them bench tested. Both met specs for stability, devation, purity, the works.

So, I'm back at square one, reading the notes on the board for hints on how to pull this off.

Martin

Just curious, do you happen to have the scanner antenna located very close to the systor's antenna? I have seen a guy once who had his scanner and two way hooked to the same antenna, not a good idea. I'm assuming you wouldn't do this but thought I would mention it just in case someone was following this who might try that.


I really think you should be able to do what you want with a scanner.

chiefhal3 wrote:Just curious, do you happen to have the scanner antenna located very close to the systor's antenna?

Both Syntors conect to their respective NMO quaterwave on the roof. The scanner was inside the truck, sitting on the console, with a rubber duck antenna (store demo models).

I would love to just stick the scanner in the console & be done with it

Martin

Well, you will get that with most scanners, and even radio's. Your putting 100 watts out, and anything within 1-20 feet of that antenna is going to get splashed pretty hard.

In fact, our 45watt radio interfere with out TV in the station from the parking lot. That's 5 brick walls and steel reinforcements, and still kills CATV that buried in the other side of the building.

As pointed out, a trunking or digital trunking scanner would be the way to go...far less expensive than a digital radio...and takes out a lot of variables and worry's.

Follow up to my original question: I have had to return 2 scanners to Radio Shack for going brain dead. I'm now on Scanner #3, which the manager took great pains to make sure was not in the same production lot as #1 & 2.

It was suggested by a local amateur to grab a used 800 MHz duplexer & put it between the scanner & antenna to notch out the VHF & UHF. BTW, I know this would make the scanner useless for anything else

Comments, ideas, anything??

Martin

alex wrote:I'm suprised that RKG didn't jump in there and say you also have to convert those talkgroups to Hex.

RR has them listed both as decimal and as hex.

On a different note, how does one know if the system is "message" "transmission" or "PTT-ID"?

John

k4wtf wrote:On a different note, how does one know if the system is "message" "transmission" or "PTT-ID"?

For RX-only purposes, it doesn't matter.

If you have a need for Transmitting, the best thing to do is ask the radio system manager, or read an active radio. If neither of those are an option (and you still have to transmit?!) you can figure it out this way:

If the system does not allow users to double, i.e., if someone keys-up while someone else is talking and they get a busy-tone, then it's Transmission.

Message & PTT-ID are very similar, and Trunker can help distinguish the two. If Trunker properly shows the radio IDs change during an active conversation before the repeater drops, then the radios are set for PTT-ID (they send an ID on each key-up during an active conversation). If the radio IDs don't change before the repeater drops, it's Message.