[TR] TR4 radio

[tr3driver at ca.rr.com]

> Is the drop in overall voltage causing this problem?

Seems fairly clear the (normal) drop in voltage is causing the loss of sound.  But it shouldn't do that.

> Is there a fix other than adjusting the idle to over 1000 RPM?

I would be looking for any reason the radio is not getting full battery voltage, like maybe it's not well grounded or has a bad connection somewhere.  If possible, measure voltage both at the battery and right at the radio, with the engine not running.  The radio should work fine down to at least 10 volts (usually even lower than that) with only a very minor drop in volume.  If it's losing a lot of volume at 12 volts (which is about the minimum you should see), then the radio itself has a problem.

Randall