Yaesu FL-2100Z Conversion

 This is another Yaesu FL-2100Z that I converted to Russian GI-7B triodes. This is a straight forward conversion... Remove the old tubes and tube sockets (horizontally mounted), remove the bottom mounted fans, install new sockets in place of the fans, power supply mods, install a bias control circuit, installed two fans to cool the filament connections, two additional fans to cool the anode connections, mods to the tuned input, relocated the output padding caps, installation of a high voltage interrupter, etc. That's all :-) Here's a few pics and info...

This is a version of the bias circuit I used in this conversion.

A fuse was installed in the cathode circuit.

Protection installed on both panel meters.

I wired it for 110v operation.

Tube socket used in the conversion...

Sockets spaced below the chassis...

Sockets spaced carefully, to allow anode clearance between the plate choke and chassis wall. 

Relocated tank padding caps.

Plate bypass cap...

Testing the HV supply and interrupter...

Interrupter and glitch resistors installed...

Bias switching transistors...

Connections between filament choke and socket...

Fans to cool base of tube sockets...

Voltage doubler for DC control circuit...

HV interrupter (L), glitch resistors (R)...

30w drive used to test tuned input and for initial tuning...

Bias transistor...

Tuned input with capacitor changes in place...

Mod to tank circuit on 10 meters...

HV transistor for bias control. 

Cannon-Ball Headphones

 This is a set of Cannon-Ball Headphones, made in Springwater NY around 1945. They are common WW2 era headphones often used with crystal radio sets of the day. To me, these are very uncomfortable, but headphones have come a long way since that time :-) From google:

"Cannon-Ball Master" headphones from Springwater, NY, refer to vintage, often antique, headsets made by the C.F. Cannon Co.. These were typically high-quality, military-grade, and designed for radio reception, with "Master" and other model names like "Empire" indicating different versions.

About these headphones

• Manufacturer: C.F. Cannon Co.
• Location: Springwater, New York
• Era: 1920s to 1950s, with models including the "Master" and "Empire"
• Features:
  • Made in the USA
  • Often described as military-grade
  • Antique or vintage design
  • Built for crystal radio reception