WD2XSH/31
(WA1ZMS)
Homebrew 1920 MOPA (Master Oscillator, Power Amplifier) rig that would
have been vintage in the early days of real 600m amateur operation.
(See "Radio Telephony for Amateurs" by Ballentine page 124.)
Click here for .pdf of the above
Hand keyed CW with a 1917 Clapp-Eastham straight key.
The rig is running a couple of watts into a Marconi-T
antenna feed against ground.
Engraved brass tags for the front
panel will be added.
 
 
Oscillator is UV-201 and final is UV-202
 
Power supply built with all vintage parts (except for modern
bleeder resistors! Original design didn't have any back in 1920.
 
 
Present operating position. A 1920's Grebe CR-8 receiver
will be used with the MOPA transmitter for 500 KHz operating.
 

XYL helping drive ground extra rods near base or Rohn 25 tower

with VHF antennas.   All grounds are now tied to common point.

 

WA1ZMS sending CQ on 497KHz. Antique tubes and radios
can be seen on back shelves in shack.

Have to adjust that filament voltage to keep the 1920

UV-202 running and not burn it out. 

Ladder line feeing 160m dipole as the hat of the Marconi

T antenna. After improved grounding, antenna feed resistance

is now 19ohms. About 15 of that is still due to ground loss.