"searched" trunked freq.s

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dvendt

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I have found quite-a-few 800 mhz freq.s using search and sweeper that aren't listed on the radio referance database and am wondering if there is an easy way to decode the tgrp parameters. The owners manual does not do a good job at explaining things. The "Easier to read" manual is better but still lacking on how to's.
Any help in explaining how to do this would be much appreciated, if there is in fact a way of decoding.
Thanks,
Dave
 

Spitfire8520

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It sounds as if you have found a new voice channel and are trying to pull the talkgroup information from the voice transmission independent of following a trunked system. If this is the case and you are using a PSR-500, then I do not believe there is such an option for being able to pull the talkgroup information from a voice channel. The closest option you have to identifying what voice frequency goes to which trunked system/tower is to either know the NAC assignment scheme for the different sites that you can hear with your trunked radio system, or do an FCC license search using frequencies and then going through the license information to find out where they are assigned.

If you have found what you think is a new control channel, then you should be able to identify the type of system it is (assuming you are using the PSR-500). You can then program the system and attempt to use a wildcard to find new talkgroups.
 

Spitfire8520

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To follow up on what I noted earlier regarding voice frequencies, the whole NAC thing only applies to P25 trunked systems (slipped my mind). You can actually use the PSR-500 to find the NAC for each of the sites by going to the control channel and then looking for the N*** next to the decode percentage.

Otherwise, you may have to depend entirely on the FCC license search if you are using only a PSR-500 for other systems. I live in a P25 trunked system saturated area, so I do not have much information regarding figuring out frequencies for other types of systems that aren't P25.
 

ecps92

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Each site (Zone) MIGHT have it's own NAC. maybe Not.

The 500/600 should show the NAC based on the Control channel

You will never find SysID, nor NAC, PL/DPL via the FCC and with some systems you won't even find the lat/lon of the site (Market or Statewide Licenses)

Once you find the NAC, PLEASE do submit it to the RRDB

To follow up on what I noted earlier regarding voice frequencies, the whole NAC thing only applies to P25 trunked systems (slipped my mind). You can actually use the PSR-500 to find the NAC for each of the sites by going to the control channel and then looking for the N*** next to the decode percentage.

Otherwise, you may have to depend entirely on the FCC license search if you are using only a PSR-500 for other systems. I live in a P25 trunked system saturated area, so I do not have much information regarding figuring out frequencies for other types of systems that aren't P25.
 

detroit780

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NAC

Actually NAC applies to P25 not just P25 trunked. NAC is similar to CTCSS or DCS. It can apply to P25 trunked and it can apply to P25 conventional.

NAC - The RadioReference Wiki

To follow up on what I noted earlier regarding voice frequencies, the whole NAC thing only applies to P25 trunked systems (slipped my mind). You can actually use the PSR-500 to find the NAC for each of the sites by going to the control channel and then looking for the N*** next to the decode percentage.

Otherwise, you may have to depend entirely on the FCC license search if you are using only a PSR-500 for other systems. I live in a P25 trunked system saturated area, so I do not have much information regarding figuring out frequencies for other types of systems that aren't P25.
 

KE5TLF

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Be aware that the GRE based radios from that era are notorious for "ghost": images of actual frequencies. Be diligent that you are on the actual freq, and not an image. Anything outside of the 851 to around the 858-859 range is certainly bogus for an output freq, for instance. Once you find a control channel, and even if it isn't the correct freq. programs like UniTrunker, T88, or Pro96Com will usually calculate the correct freq from the CC data.
 

Spitfire8520

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Actually NAC applies to P25 not just P25 trunked. NAC is similar to CTCSS or DCS. It can apply to P25 trunked and it can apply to P25 conventional.

NAC - The RadioReference Wiki

I am aware of this, I was just keeping my answer in the context of an instance of a trunked voice frequency rather than a conventional frequency based on the OP request for pulling talkgroup information from a frequency.
 
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