1930s Crystal Oscillator Transmitter #1

Gil Johnson, W1DZ, designed Crystal Controlled CW transmitter from the 1930s.

This is the Ca. 1930s Crystal Controlled CW Transmitter in the NEWSM collection.

This Crystal Controlled Transmitter is designed to have a more stable frequency control than the TPTG and TNT transmitters in the NEWSM collection. Instead of using a variable capacitor to adjust the transmit frequency, it uses a crystal controlled oscillator. This one has an UX-210 tube (8V Filament, 425Vmax 425V@ 22mA, 1540mW Max Power) for the RF oscillator, and an RCA-247 pentode tube (2.5V Filament, 250V Plate Voltage Maximum, 22mA Plate Current Maximum, 3100mW Max Power) for the Crystal oscillator.

The crystal for the oscillator was made from a quartz eyeglass lens. We need to reverse-engineer the schematic for this transmitter to determine what power supply is needed.

Click on an image to see a larger view.

References for TNT (Tuned plate Not Tuned grid) transmitter