NCPD Digital system on 796D. NOT an encryption quesion.

I know I can listen to MEDCOM and nothing else. I do monitor MEDCOM on a PSR-800 and HP-1, but they are pre-programmed.
I do have the system working on a 796D. I get the activity monitor and lock out the encrypted groups.
BUT, when I get MEDCOM 6001 it does not stay on transmission, it just goes back and forth between scanning and playing.
So I am assuming it is probably a problem with the fleet plan on this radio.

Anyone know the custom band plan to make it work right?

Funny thing is, it will hang on the ENC channels but does not want to stay on the unencrypted ones. It does seem to decode propertly. But I get like 1.5 seconds of voice, 1.5 seconds off, 1.5 seconds back on. Almost like priority is set (not).

Anyone got a band plan idea or any other reason for this?

It appears to be going back and forth between the voice channel and the CC, instead of holding on the VC while there is an active transmission. Even if I set the delay to infinite, this happens. I can confirm with my PSR-800 that it is NOT a problem with the transmission, so I am guessing I need some kind of band plan. I have tried all the standard settings and none seems to do any better, some do not trunk at all.

Any help appreciated.

I also have it set now to ID SCAN, and 6001, 6002, and 6003 are the only TG's listed. But no matter, it won't stay on the transmission.

The funny thing is, when it stops on an ENC channel, it does not do this, it just stays there and puts out the garbled signal, When it stops on an UNENC channel, it constantly flashes back and forth between the CC and the VC. I think unless it is an incompatibility in the radio it should work. The decoding is perfect.

And here is some strangeness that must be a clue:

I heard unencrypted TG 4021, and it worked perfectly. So possibly there is something wrong in the way it is seeing my TGID list? I deleted the 6001 entries, now to see what it does.

If you are hearing 4021 without any issues you should be hearing 6001, 6002, and 6003. I am monitoring both "Towers" with UniTrunker and other digital scanners without any issues that I am aware of on the unencrypted talk groups. Which tower are you monitoring? If you are picking up T101, then keep your eyes on 60001 (That's Sixty THOUSAND and 1) for unencrypted traffic and see if you can follow that TG around.

There is also A LOT of data activity now on the trunk system. Instead of using one of the Medcom channels to send data across, the ambulances now use the trunk system. I see data popping up now all the time. It also seems that possibly the Town of Oyster Bay had data terminals out there too, but I could be wrong. I'm just assuming that TOB is using them based on the UID's.

Below is the bandplan from UniTrunker. The strange thing here is that it is broadcasting Phase 2 capabilities on the 700Mhz spectrum that the county is not yet using. I would assume when the EDACS system migrates into the P25 system, that maybe they will shift down to 700MHz....and that's another topic for another thread

On another thought, have you considered hooking the PSR-800 to Pro96Com or the HP-1 into UniTrunker?

I am using ProScan and I don't even have a way to load that config!

I remember seeing somewhere an online calculator that took P25 channel numbers and allowed you to figure out the upper and lower settings, but I can't find those now.

I have an old screen grab of Pro96com's band plan located here: http://www.w2lie.net/apps/forum/forum_viewtopic.php?3890.10#post_3975

But it was my understanding, that in theory, that the band plan information was transmitted over the air, so there would be no reason to add that into the scanner. But - I also believe, that the older P25 scanners were not that smart. I'm pretty sure that the PRO-96 and PRO-2096 required the band plan to be manually entered into the radio to properly function. My PRO-2096 has a faulty display now (2nd time after the repair) so it's just a paperweight to me now.

I have it set to Type2/UHF P25
The only choices are Base, Space, Offset.
No other trunk options seem to work at all.
I suspect the radio is just too old for this type of system,

It is just strange that it appears to trunk track properly, and the ENC groups stay on channel, but 6001 does not, it switches back and forth between voice and control, resulting in cut off transmissions.
Probably the radio is just not compatible. My newer radios monitor this just fine.

I have come to the conclusion that this radio just can not work properly on this system. IT does decode, it does track properly, but it does not interpret the cc properly, or it sees the channel as encrypted, because it just keeps flashing back and forth.

So the exercise is ended.

So, this is where it gets totally weird.

I programmed my 296D, which is supposedly the exact same hardware as the 796D. I used the same data file from the 796D to program the 296, using ProScan.

Guess what? The 296 receives this system perfectly, holds on the voice channel as it should. No matter what trunk settings I use, the 796 flashes back and forth between the CC and VC.

This is a real head scratcher. The only thing left is to do a factory reset, but not sure how that would help because everything else in the radio works perfectly, just this silly system won't work properly, with a setup that works on the 296. HMMMM

WAG question - is the 296 firmware up to date, and the 796 is not? Mike

ka3jjz said:

WAG question - is the 296 firmware up to date, and the 796 is not? Mike

Click to expand...

I am pretty certain the 796 must be up to date because all the re-banded stuff works, but I will check to make certain.

Actually, that was a GREAT catch!!!!

I had 2 296 units, and took the digital card out of one and put into my 796. I am nearly certain I had updated the cards years ago, but I did the update in the 796 and VOILA!!! Now it works perfectly!!!!!!!

Thanks for the tip, it got me headed in the right direction. It is possible the card needed to be updated in the 796 to function 100% in that radio, as opposed to the 296.

There seems to be conflicting reports about the 296 and 796's floating around in other threads on this site concerning P25 reception.

Do these radios still require custom tables (band plan) with the latest firmware, or do they grab the table from the control channel like modern radios do?

talkpair said:

There seems to be conflicting reports about the 296 and 796's floating around in other threads on this site concerning P25 reception.

Do these radios still require custom tables (band plan) with the latest firmware, or do they grab the table from the control channel like modern radios do?

Click to expand...

I don't know. I put in a custom band plan, but I think it was scanning fine without it (see above).