Score of the Year! Free Multi-kW HF Linear Amplifier!

Ahhhh how I love attending a college with active research labs decades older than me!

Where else could I score a free Multi-kW HF Linear Amplifier!?!?!?!

Anyway, this find is most definitely my find of the year. This SERVER RACK SIZED amp was a CW (continuous wave) RF source for a Sputtering System in one of the materials labs at my university. Every once in a while these old research labs get some money and decide to renovate. When they do this they discard old equipment in certain areas for recycling. Many times this equipment is in perfect shape and very valuable if you happen to know what your looking for… and when and where to find it.

This is where I come in. Over the past 10 or so years that I’ve been hanging around my college I’ve become an expert in dumpster diving this electronic junk. This amplifier is simply my most recent find and possibly my most valuable one to date.

So why am I excited about this specific piece of equipment?

  1. It’s a MASSIVE AMPLIFIER! It can boost an RF signal 15 to 17 times with an output of several kW!
  2. It can be easily modified to work on Ham Radio Frequencies! (I’m a Ham!)
  3. It’s worth A LOT in parts alone! (similar Ham Amps are several $1000’s)
  4. Nearly everything to make it run is present and intact

Now for the nitty gritty…

This Amp consists of 4 main components all housed in a convienient rack with wheels.

  1. The power supply (High voltage system, tube filament transformers, etc…)
  2. Control system (relays, metering circuitry, etc…)
  3. RF exciter (100w Sine Wave Generator @ 13? Mhz ISM)
  4. Main RF Deck

The RF Deck is the most important component. This is the heart of the amplifier. It uses a 3cx3000a7 Triode Vacuum Tube with a rated plate dissipation of 4000 watts. The Amp is in a common zero-bias grounded grid configuration with a tuned input network and a Pi-L output network. If the 3cx3000a7 tube is good, it alone is worth almost $1k.

Here is a hand drawn schematic of the Main RF Deck…because I’m awesome



Getting this Amp up and running is now one of my primary projects.

The Goal: Turn this Amplifier into a legal limit (will easily go above ๐Ÿ™‚ Ham Radio amplifier for the HF bands.

Here are some more pictures until I finish writing this post:






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