I was sort of intrigued to follow a group of Hams at the CVARC club to build an amplifier. There was a choice of building a Solid State devide that put out approximately 140watts on 180-10m, OR a tube based amplifier, and depending on the Final Tubes anywhere from 150w – 2KW.
My original intention was to build the 140 watt Solid State amp, but I already had a lower power out (45w) amp still in a bag with all the loose parts ready to build, so making another that replaced this one that I haven’t built yet seemed unnecessary.
On to a tube amplifier !
Never built a linear amplifier (tube based) and thought it was a good idea. (hmmmm)…
So with the help of Rod Blocksome K0DAS as our mentor, I embarked on a rather strenuous task of making one from scratch…
Lots of decisions to making an amplifier, starting with How much power out? What bands? What Tubes to use in the final???ALC, T/R, Meters etc…etc…etc..
So my initial thought was just a 500w single 3-500z (because Rod had one lying about not being used…So that was a start..for a hunt for about 50 other pieces needed. Initially a Power Supply..that means Honking big transformer…So before I go any further and with a ton of suggestions from ROD,(we) decided to make it a full Kil0watt !!!I can always start off with a Single 3-500 and add the second tube…
Ok that changes things, now i really need a power supply that can provide 3KV at about 1/2 amp !!..So off to the hamfests..
Got a sweet deal on a supply almost totally perfect for my needs..sort of…EXCEPT.
Had to build the chassis from scratch to be able to hold this honking big transformer that has 3600v secondary, 3000v secondary, and a 1400v secondary. 8 – 100Uf 450v caps couple of smoothing caps a bridge rectifier and some healthy wire Dual Circuit Breaker and Voltmeter.
So how do i mount those caps? WALMART Cutting boards @ $ 0.88 each !!and some RTV to secure. Ok so after spending about 25 hours on making a chassis and 20 dollars for the rest of this supply….Not bad!…so far.