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Published in QST magazine (December 2004). Also see ARRL web files.
The 23 cm amplifier pictured here delivers more than 300 watts with 10 watts drive. I've actually driven it to 400w+. It's water-cooled, thermally stable, and very smooth-tuning. It includes a TR switch, relay sequencer, and all controls necessary to operate the amplifier safely and reliably.
click any of the thumbnails below for enlargements or explanations
| The Completed Amplifier | The Performance Test | The modified GS-15B Tetrode | Why Water Cooling? |
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At it's heart is a Russian tetrode, the GS-15B, modified for water cooling. It runs in a well-made cavity I purchased from Mats Bengtsson, KD5FZX. Complete information on the cavity itself can be viewed here, courtesy of Mats and Paul Goble, ND2X.
Featured below are construction details on the complete amplifier and power supply I built for this cavity. Click here for the complete schematics.
| Simplified Schematic | Power Supply 101 | +28 and +12 volt supplies | Bias and Metering |
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| Relay Sequencer | Mounting the Cavity | Coolant Connector Parts | RF Relays |
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| Some Other Parts | PCB Mounting | Cavity and 2nd Fan Mount | Ventilation |
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| RF Cabling | PCB Wiring | PCB Component Side | Wiring View (top) |
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| Another Top View | HV and Disconnects | Other Disconnects | Rear Panel Lettering |
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| Power Supply | Tuneup | ||
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