VA3TO version of the W6PO 2m amplifier.
1.5 KW output @ 144 MHz.

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The Star of the show

Front Drawing | Front Mock-up

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Cut Material | Plate Lines | Plate Clamp | Tuning Parts

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Left View | Top View | Back View | Bottom View | Right View

The desire to hear my radio echoes off the moon inspired me to build this full legal limit "QRO" amplifier for 2 meters. So far my modestly successful moonbounce endeavours have been accomplished using a 275 watt solid state amplifier but physics and math dictate that I need more power to hear my own echoes. I chose to build an 8877 triode tube amplifier based on the proven W6PO design. A reprint of the original construction article is posted here.

My version deviates from the typical 19" wide rack-mount form factor because I wanted a desktop amplifier. I was able to scale down the width but not the height due to the inherent design of the RF compartment. This amplifier is 14" wide x 10.25" high x 10.25" deep (excluding protrusions).

A G3SEK Triode Control Board was employed for Grid supply & Grid/Plate/HV protection. The board kit is a bit pricey but worth it in my opinion. I may never know that one of the times a fault trip occurs might have resulted in fatal damage to the tube had the protection board not been used. Cheap insurance for a $500 tube !

The front panel was designed in AutoCad(TM). The artwork was given to an aquaintence who runs an engraving business. The raw material is clear 1/16" plastic that comes painted on the back side. The Acad file was masaged then loaded into his computer operated X-Y engraving machine which reverse engraved the lettering on the painted side and milled the through-holes and cut-outs. The lettering was opaque after engraving so I used some Testors model paint to colour it to my liking. I'm happy with the result and because it's done from the back side, the lettering will never wear.

The trial version of "Meter" by Tonne Software was used to produce new meter scales. I printed them onto white label material using a colour laser printer then applied them to the meter faces. The meters look like they were made to order from the factory !

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