Parasitic Chokes

[wavebourn]

Tolly, 12AU7s can be wired for 6.3 volts. There are 3 heater pins someone
correct me it has been a lot of years.  This allows you to put both heaters in parallel. good luck!

However I know Frank that the 9'th pin is the middle betwen 4 and 5 pins, but I won't resolder  anything in the radio. It is still original Collins made peace of history.

[WA1GFZ]

I understand now.
I once considered building a power supply inside the case. I thought about removing the power connector and install a plate over the hole. Then a power cord could come through the plate. Maybe a little switch would also fit on the plate or the spare fuse holder could be removed and a switch
could go there.
The radio took about 28 volts at 3.5 amps with most of the power used by the audio output. I have heard the radio works better with a little higher plate voltage.

[wavebourn]

I have heard the radio works better with a little higher plate voltage.

Especially in terms of intermodulations.
It is exactly what I am going to do!

[WA1GFZ]

I always thought the best thing to do would be rip out all the tubes
and use transistors running class A but AGC would be a problem.
1 module at a time starting from the speaker to the RF input is the path I would have taken. It becomes a big science project.  

BTW I notice you use the term crapstal. This is a good sign you will be using "strap" soon.  welcome!

[wavebourn]

I prefer to use tubes in RF and 1'st IF.

However, before I saw a schematics, I considered to rewire filaments, because I did not know that B+ and filaments are powered from different pins of sockets. In such case they could be rewired to any voltage. But when I discovered that filaments and plates are powered separately I decided lo leave all wires on place, may be to convert from 26 to 12 volts, since 12 volt versions of the same tubes are much cheaper and widely available.