power source and draw from PRC-47

[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 hell 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?

 

[tennmogger]

Hi Mike,

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

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 hell 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?

 

[maddawg308]

Awesome, thanks for the info, Bob! KI4JSC