W7GBI 813 x 813 Transmitter

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Charlie Justinak, W7GBI, started building this AM rig a year or two  before he passed away on Feb. 12, 2008.  K7JEB purchased the various chassis and parts from his estate to continue with the construction.  It pained him to think of Charlie's work being "parted-out" on E-Bay, or worse, making a one-way trip to the landfill.  Bob, NA7RH bought the parts from Jim two years later and is actively finishing the rig.

The rig runs a pair of 813's in the final, modulated by a pair of triode-connected 813's, and is based on the K1JJ design.  Charlie originally planned for the transmitter to cover 160 and 80 meters.  However, it would be beneficial to extend that coverage to 40 if at all possible.  The rf and audio drive will be provided by a Johnson Ranger II that Charlie procured for the purpose.

The most incomplete part of the rig is the power supply.  There are several options available.  One is to use an existing chassis (pictured) that contains a fairly hefty transformer that supplies 2000 VAC CT with a full-wave bridge.  The other is to start from scratch with what K7JEB calls the 'submarine transformer' that is rated at 1470 VAC @ 1.2 amps in a capacitor-input filter setup.

More notes to come later....

Rig Photos and Schematics:

K1JJ 813x813 Transmitter Schematic (128K)

K1JJ Power Supply Schematic (for Xmtr) (148K)
RF Deck, Front View (300K)
RF Deck, Top View (377K)
RF Deck, Bottom View (447K)
Modulator, Front View (384K)
Modulator, Top View (333K)
High-Voltage Power Supply, Top View (300K)
Alternate Power Transformer, 1450VAC @ 1.2A  (260K)
Screen/Bias Power Supply, Top View (280K)
Screen/Bias Power Supply, Front View (333K)
Screen/Bias Power Supply, Bottom View (406K)