Page 1 of 1
PacRT help needed
Posted: Fri Jul 20, 2007 10:07 am
by Motrac
Please see photo at link below. Just got this rascal, with the intention of interfacing w/SyntorX VHF mobile & HT1000 & MT500. I have no clue what's going on here, and can't really figure out why there are 3 'sponders, and no 'senders. Is the center board 'sponder reflective of the tone it should be receiving from the attached Syntor, or what? If so, I'm guessing that's the Tx board, and that the other two are the receivers?
Many thanks for any "PacRT Theory 101" lessons anyone cares to offer.

I have a manual ordered, but the radio beat it here, and I'm not optimistic about when I'll receive it.
http://home.comcast.net/~muddville/PacRT.jpg
Re: PacRT help needed
Posted: Thu Jul 26, 2007 4:50 pm
by kf4sqb
If memory serves, the reeds in the two outside boards are for receive PL, while the one in the middle is for singletone. The board on the 'top' of your picture is the transceiver for the 'HT' side of the system, the board on the 'bottom' is most likely a "monitor receiver" board, and I have no idea what the middle board might be. The HT only uses PL into the PAC. The PAC does not transmit a PL when talking back to the HT. The monitor receiver board was used in some non-repeated duplex systems, and is a receiver only. The singletone reed is part of the priority resolution scheme used by the PAC-RT when several are on scene at once so that only one does all the repeating instead of all of them trying to repeat at once.
Re: PacRT help needed
Posted: Sun Jul 29, 2007 5:00 am
by Motrac
Many thanks. The service info I have now doesn't address multi-frequency models, and I was a bit stumped all the way around. What you're telling me makes a lot more sense than anything else I've found on the subject thus far.
Still looking for info on installation/use without a Converta-Com, which is another under-documented subject. I haven't even been able to find a part number for the on/off switch that was commonly used in place of a Converta-Com.
Re: PacRT help needed
Posted: Tue Jul 31, 2007 5:50 am
by kf4sqb
The manual control switch's part number is NLN4537. IIRC, you would tie yellow and brown together and put them on one side of a switch, and put the red on the other side of the switch. I may be mistaken about that, but I think its right. Oh, and all those wires are in the small grey cable that comes out of the connector that goes to the front of the PAC. This cable should have a round, screwshell-type connector, like the mic connector of the old radios like the Mocom and Motrac. If it does, the red wire should be on pin# 1, the yellow on pin#2, and the brown on pin# 4.
One thing to remember if using the manual switch with the PAC: you have to remember to switch the PAC off when getting back in the vehicle!
If you're not already familiar with the site, you can find a lot of info on the PAC series, as well as the Syntor and Spectra radio series', on
Mike Blenderman's website. The specific info on the PAC series can be found
here.
Re: PacRT help needed
Posted: Tue Jul 31, 2007 9:46 am
by Motrac
kf4sqb wrote:The manual control switch's part number is NLN4537. IIRC, you would tie yellow and brown together and put them on one side of a switch, and put the red on the other side of the switch. I may be mistaken about that, but I think its right. Oh, and all those wires are in the small grey cable that comes out of the connector that goes to the front of the PAC. This cable should have a round, screwshell-type connector, like the mic connector of the old radios like the Mocom and Motrac. If it does, the red wire should be on pin# 1, the yellow on pin#2, and the brown on pin# 4.
One thing to remember if using the manual switch with the PAC: you have to remember to switch the PAC off when getting back in the vehicle!
If you're not already familiar with the site, you can find a lot of info on the PAC series, as well as the Syntor and Spectra radio series', on
Mike Blenderman's website. The specific info on the PAC series can be found
here.
Thanks very much, kf4sqb!
The connector for the grey cable has been whacked, but all the wires appear to be present. (See photo) - I'll see if I can find the original switch somewhere, but if I can't, at least I know how to work around it. Didn't get to use these much in the field, but I do remember being reminded to kill the Pac-RT when we got back in the car...right after we stabilized the coffee and doughnuts. :-0

Re: PacRT help needed
Posted: Tue Jul 31, 2007 11:45 am
by kf4sqb
Glad to help. If I can be of any more help, don't hesitate to ask. I may scan the manual I have sometime this week. If I do, I'll let you know and see about making arrangements to send you a copy.