On 20 Oct 2008 18:30:57 GMT, elaich wrote:

"Henry Kolesnik" wrote in news:qK0Lk.5910
:

An HRO 7 will tune down to 50 Kc with the proper coil set and I'd guess
that some of the other HROs will too!

Jeez, if I had an HRO 7, I wouldn't need to do this to begin with! LOL!

I'm going to use the Lear tuning head to feed the 85 kc IF of the R-11a. My
big problem will be voltages. The R-11 uses 14 volt tubes, wired in series
pairs. That was for the plane's 28 volt system. I'll have to rewire them in
parallel and feed them 12 volts. I haven't looked at the Lear yet, but it
probably uses the same idea.

While you're rewiring the heaters consider replacing the metal-cased
caps under the chassis. They will have to be removed to access the
tube socket bases.

An alternative to rewiring the filaments is to build a power supply
using a 24 V transformer. My Q5-er supply uses back-to-back 25.2V
transformers to feed the rectifier/filter circuit. The filament
voltage is taken from between the two transformers. A 6.3-0-6.3V
transformer supplies 6 & 12 volts.