PRT4A question
Moderators: rickf, raymond, Mr. Recovery
PRT4A question
two questions, actually---can i get the battery for it, and if so where? can anyone tell me the two frequencies on which it operates, so i'll know if it can communicate with my RT524?
Re: PRT4A question
Honestly, you should have just called me, but for those interested...
1. BA-399/U batteries are available through a fellow in Canada. Their exp date is 12/68 but surprisingly most are still hanging in there and will carry the load for a few hrs. They provide a minimum of 13.8v I've seen PRT-9's operate and actually transmit using a single 9v battery. Having the original outer cardboard battery box provides a holder to visibly disguise whatever civilian batteries you want to use to provide a cost effective power source. I have also found the long round batteries for the PRR-4's. They can be used to load modern batteries and still keep the visual appearance original. 10 AAA's would fit and feed it with 15v. I saw at Gilbert a guy that had 2 9v's wired with a resistor to drop the voltage a bit.
2. The frequencies for both the transmitter and receiver are crystal controlled. They have an "offset" so the freq printed on the side of the crystal is 10.7 mc below the actual frequency the equipment will operate on. I have a few TM 11-5820-549-12's for them if your so inclined. The factory freq issued was 51.00mc, hence the crystal for 51.0 would be marked 40.30000 or 40M30000 Other crystals for other frequencies are available and not too hard to find. I also use 48.8 so that crystal is marked 37.10000
There is also a power difference between ch1 and ch2. Chanel 1 (high power) transmits at 450 mw, channel 2 (low power)transmits at 50-250 mw (that's miliwatts). Most common was 51.00 in both and the channel control was just for high and low power choice. 48.00mc and 51.00 mc falls right into RT-524 and PRC-77 freq's.
Rainman
1. BA-399/U batteries are available through a fellow in Canada. Their exp date is 12/68 but surprisingly most are still hanging in there and will carry the load for a few hrs. They provide a minimum of 13.8v I've seen PRT-9's operate and actually transmit using a single 9v battery. Having the original outer cardboard battery box provides a holder to visibly disguise whatever civilian batteries you want to use to provide a cost effective power source. I have also found the long round batteries for the PRR-4's. They can be used to load modern batteries and still keep the visual appearance original. 10 AAA's would fit and feed it with 15v. I saw at Gilbert a guy that had 2 9v's wired with a resistor to drop the voltage a bit.
2. The frequencies for both the transmitter and receiver are crystal controlled. They have an "offset" so the freq printed on the side of the crystal is 10.7 mc below the actual frequency the equipment will operate on. I have a few TM 11-5820-549-12's for them if your so inclined. The factory freq issued was 51.00mc, hence the crystal for 51.0 would be marked 40.30000 or 40M30000 Other crystals for other frequencies are available and not too hard to find. I also use 48.8 so that crystal is marked 37.10000
There is also a power difference between ch1 and ch2. Chanel 1 (high power) transmits at 450 mw, channel 2 (low power)transmits at 50-250 mw (that's miliwatts). Most common was 51.00 in both and the channel control was just for high and low power choice. 48.00mc and 51.00 mc falls right into RT-524 and PRC-77 freq's.
Rainman
M151 World Land Speed Record Holder
Re: PRT4A question
thanks, ray---i could have called, but with the time difference, i didn't want to interrupt your dinner. LOL. thanks, especially because i didn't know there had to be a second unit to receive. glad i didn't buy it on impulse. i was thinking along the lines of being a walkie talkie type that would talk to the jeep when i was away from it and linda was nearby.