[ARC5] Cold filament protection

[Tim]

I used a 2 watt, 1 Meg resistor as a "coil form" and wound about 5 feet of
30 Ga. magnet wire around it for a resistor (electrically in parallel).
Shrink-wrapped.  Cheap insurance for tube filament protection in my
PRC-25.  Works great, no tube problems with my periodic use after 30 years
or so.  I don't notice any performance loss in use, although I didn't
measure the RF output with/without.

I use 2 alkaline D Cells in series plus 2 rechargeable 6 volt, 6.5 A-H SLA
batteries in series for 12 volts and it all works fine.  Fits in the
battery box nicely.  I recharge the SLA batteries via the front panel
connector; the D Cells seem to last forever.

(Required ARC-5 content:  Did a PRC-25 ever fly in an aircraft equipped
with an ARC-5 set?)

Thanks for your great website Brooke - very valuable!

Tim
N6CC
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mailman.qth.net/pipermail/arc5/attachments/20180315/f75d55b8/attachment.html>