I would like to take my PRC-47 radio set to the VA rally to operate it in the field this coming weekend. I do not have the proper power source for it, it uses either 24 volt DC (like a 24VDC jumper genset would provide), or 115 VAC 400 Hz. I was wondering if I could get input from someone who is electrically minded. I guess I could run it off the 24 VDC batteries on my deuce, but I wasn't sure how long I could run it off the batteries until the batteries were too dead to start the truck. I surely could run the truck at the same time to power the radio, but then it would be loud as **** and I wouldn't be able to hear myself think, much less talk.
Anyone out there have some amp draw data for the PRC-47 on the low power setting, and some thoughts on the possible length of time I could operate the set on the low setting before the batts were dead?
__________________
Mike
maddawg308
FCC # W1AMR Extra Class
MVPA #33431
NRA Life member
2003 Dodge Durango SLT 4.7L V-8 parts hauler
1967 Stevens M416 trailer
owner of the "Dawg House" travelling Vietnam radio hooch display
avatar: Capt. Malcolm Reynolds from Firefly/Serenity
I did some looking and found these specs for the PRC-47 for use on 28 vdc: on transmit the power consumption is 320 Watts, on receive it uses 21W.
Converting this to amps (at 28 vdc) that's about 12 amps on transmit and less than 1 amp on receive.
Depending on your truck battery AH (ampere-hour) rating, you could listen for many hours with little drain on the battery. In transmit it uses much more power, but transmit is usually done for only a small percentage of the operating time.
If your truck battery is good for, say, 100 AH, you could probably use half that and still start ok. That gives you 50 AH to play with. That's about 4 hours of actual key-down transmit time. That's a lot of time if you listen 90% of the time and talk only 10%!!
Seems to me you don't have to worry too much about running down your truck battery.
Hope that helps,
Bob
WB4ETT
Quote:
Originally Posted by maddawg308
I would like to take my PRC-47 radio set to the VA rally to operate it in the field this coming weekend. I do not have the proper power source for it, it uses either 24 volt DC (like a 24VDC jumper genset would provide), or 115 VAC 400 Hz. I was wondering if I could get input from someone who is electrically minded. I guess I could run it off the 24 VDC batteries on my deuce, but I wasn't sure how long I could run it off the batteries until the batteries were too dead to start the truck. I surely could run the truck at the same time to power the radio, but then it would be loud as **** and I wouldn't be able to hear myself think, much less talk.
Anyone out there have some amp draw data for the PRC-47 on the low power setting, and some thoughts on the possible length of time I could operate the set on the low setting before the batts were dead?
__________________
1952 M-38
LST-178 Lube and Service Trailer
M-105A2 trailer, bare
M-105A2 with sides, bows
'old' Onan 115 v radar power generator, 4 cyl opposed
2 x S-250 Shelter, 318 shelter
1957 Unimog 404 flatbed, French NATO (Germany)
1965 Unimog 404 radio truck (German Army)
1970 Unimog 406
1978 Unimog 406
1982 Unimog 406
1988 Unimog U-1300L MIL contract, Fire Service life (red over OD paint)
power source and draw from PRC-47
