My primary interest in amateur radio is 160 meters cw dx. I enjoy home brewing radio gear,amplifiers having taken up much of my time over these past few years.I always have a new project or two on the workbench most of the time. I live on a small rural property near Merino,about 250 miles west of Melbourne.My wife Jeannie and myself enjoy a quiet comfortable life here and welcome the odd traveling ham passing through.

Picture is a duel band 40/20 meter water cooled 2 x GI-6B Russian triodesWater cooling amplifier tubes is very efficientThis amplifier runs all day under heavy load at 40C.The added advantage is no blower noise in the radio shackThis unit is nearly completely silent.The Russian triodes, GI-7B and GS-35B lend themselves nicely to water cooling having screw off Anode coolers.I have made several water cooling manifolds for these tubesWater flow through the two manifolds in this particular amplifier is 2 liters per minuteI have a larger 160 meter GS-35B amplifier water cooled which has a water flow rate of 4 liters per minute.

The band switching in this 40/20 meter amplifier is accomplished using vacuum relays in the Pi output network and simple cradle relays in the cathode input networks.

I am currently working on a 2 meter 2 x GI-7BT water cooled amplifier.

BobVK3ZL