Robert Smith (right) and a Partner in Crime, “Dr. Ty.”
Robert Smith, W0VMC, saw Radio World’s recent posting of a picture of his customized refurbed Collins 20V2 transmitter in “Ham Rods.” The transmitter was displayed at the recent Hamvention in Dayton, Ohio.
He sent us additional information on the transmitter.
This custom transmitter with a classic Art Deco look started out as a Collins 20V2 transmitter. It originally used 4-400A tubes, in a two modulating two configuration, but I’ve modified it to use 4-1000A tubes in their place. It now broadcasts on the 10–160M bands.
The RF and modulator deck are fabricated to sit horizontal in the cabinet compared to the vertical mounting of the original decks.
The tank circuit incorporates diode controlled vacuum relay switching that create a constant shorting tank coil and all the power supplies have all been upgraded to support the 4-1000A tube requirements. The new iron now being used was recycled from the “old Coke Machine,” a McMartin BA-2.5K transmitter.
More information on this and other transmitter revival projects can be found at his website.
Some Inside Work
