[MRCA] PRC-47 low receive audio

[scottpastor]

Gents, 

     I picked a PRC-47 at the Aberdeen show last month, that I'm just now getting around to futzing with.  When connected to 24 VDC it powers up, lights come on, and signals can be heard, but the audio is extremely low, even with the volume knob all the way up.  I'm using 2x 35 AH 12-volt batteries in series to generate power, and they're both well charged.  Is this a serious problem, or something that can be user-kludged?    


Thanks!

     -Scott, KC8KBK