Signal Stalking trunked systems....

[instrumentphilip]

Okay so I had a question I have been thinking about for a while. Okay so when I decided to read the manual for my Radio Shack Pro-106 I remember it talking about the Signal Stalking feature . . . or maybe I read about it on Scannermaster.com. It talked about using signal stalker to pick up Emergency Vehicle such as an ambulance traffic.

....

Right so let us say that I am in my car and am stuck in traffic, I look a head of me and I see my city's PD and fire on the scene. Now they are on a trunked P25 system. I turn on my Signal Stalker feature on my Pro-106 because I want to hear when they make a transmission back to dispatch. Is it possible for me to do this?

( I Already know the control channel and have it programmed and all of that case but I am using this as an example to use the Signal Stalker Feature )

Because when I think of it I think that their radio is programmed to talk to that control channel of their's in which ever language it would be using, in this case APCO 25 or whatever. So I do not think that it would work that way. Or am I wrong?

Is it possible to pick up a emergency vehicle / Squad Car / Fire Truck that are on trunked systems using Signal Stalker?



Thanks,

Phil

 

[ecps92]

Yes you can hear them, but using CC/SS you will capture them on the input freq not the Repeater output, so you will only hear the Portable/Mobile and not Dispatch

Okay so I had a question I have been thinking about for a while. Okay so when I decided to read the manual for my Radio Shack Pro-106 I remember it talking about the Signal Stalking feature . . . or maybe I read about it on Scannermaster.com. It talked about using signal stalker to pick up Emergency Vehicle such as an ambulance traffic.

....

Right so let us say that I am in my car and am stuck in traffic, I look a head of me and I see my city's PD and fire on the scene. Now they are on a trunked P25 system. I turn on my Signal Stalker feature on my Pro-106 because I want to hear when they make a transmission back to dispatch. Is it possible for me to do this?

( I Already know the control channel and have it programmed and all of that case but I am using this as an example to use the Signal Stalker Feature )

Because when I think of it I think that their radio is programmed to talk to that control channel of their's in which ever language it would be using, in this case APCO 25 or whatever. So I do not think that it would work that way. Or am I wrong?

Is it possible to pick up a emergency vehicle / Squad Car / Fire Truck that are on trunked systems using Signal Stalker?



Thanks,

Phil

 

[Comint]

. . Is it possible to pick up a emergency vehicle / Squad Car / Fire Truck that are on trunked systems using Signal Stalker?

You will pick up the frequency, but I doubt you will pick up (decode) the P25 conversation.

--
Comint

 

[fineshot1]

Phil,

Your "Signal Stalking feature" will pick up the mobiles or portables(if your close enough)
keyups on the voice input channels of the trunk system. The data exchanges on the
inbound control channel may be too quick for this feature to lock on to and display.

In the UHF(450-470) band the inputs and outputs are seperated by 5Mhz.
The repeater outputs are 5Mhz lower than the inputs.

In the UHF-T(470-512) band the inputs and outputs are seperated by 3Mhz.
The repeater outputs are 3Mhz lower than the inputs.

On VHF-Hi band there is no standard input/output repeater offset so you would
have to go by the info available by the station license.

 

[ecps92]

800 mhz will be 45 Mhz lower
900 mhz will be 39 Mhz lower [Business Band, NOT Amateur]

Anyone know the answer for 700 Mhz

Phil,

Your "Signal Stalking feature" will pick up the mobiles or portables(if your close enough)
keyups on the voice input channels of the trunk system. The data exchanges on the
inbound control channel may be too quick for this feature to lock on to and display.

In the UHF(450-470) band the inputs and outputs are seperated by 5Mhz.
The repeater outputs are 5Mhz lower than the inputs.

In the UHF-T(470-512) band the inputs and outputs are seperated by 3Mhz.
The repeater outputs are 3Mhz lower than the inputs.

On VHF-Hi band there is no standard input/output repeater offset so you would
have to go by the info available by the station license.

 

[rbrtklamp2]

700 mhz input is plus 30.0 mhz

 

[ampulman]

Wouldn't it be easier/simpler to just program the trunked system?

Looking ahead from the car, you see the problem. With one hand on the wheel, you pick up your 106, turn it on, and press the appropriate number key. Requires a minimum of distraction.

Continuing to drive, you're holding the unit with your thumb on the scan key or up-arrow to bypass unwanted talk groups. Meanwhile, your full attention is directed to the road ahead.

In comparison, after turning on the unit, you push Func-Srch, then play with the number keyes to zero in on the proper bands/sub-bands. After finding the transmission of the group(s) you are interested in, the system CC switches the transmitted frequency, perhaps out of the 1 mhz range. Now, SS has to find the new frequency. If I am correct, the frequencies are searched sequentially. which could cause gaps (delays) in the conversation. And, this would be repeated over and over. But most importantly, the dispatcher would not be heard. All of these gyrations would be unnecessary by just scanning the system.

Another possible pitfall: I have 2 EDACS systems whose towers are about 8 miles apart. There frequencies are relatively close. Wouldn't the possibility exist, where I would be picking up transmissions from both systems.

So, why not just program the system?

Of course, if the frequencies are discrete, and are not programmed, then SS makes sense.

Amp

 

[hfxChris]

So, why not just program the system?

Because as the original poster said, this was just an example so he could understand how signal stalker works?