[VHFcontesting] FS: 50MHz Amp and 144MHz Amp

Phil Theis phil at k3tuf.com
Fri Sep 23 09:47:03 EDT 2005


Updated and with Pictures

Commercial Motorola Amplifier Rack System: 50/144MHz

Fully metered Single supply dual RF deck Motorola system each using a pair of 8560AS conduction cooled tubes.  This system is fully solid state switched, and ready to go.  Has been in operation for 2/1 years at K3TUF station.  Power Supply has been modified for class AB operation.  50 MHz deck required no modifications, 144 deck only required one modification to be brought to amateur frequencies.
This is a very rugged system that has been extensively used on WSJT as well.  Metering includes separate meters for grid voltage, high voltage, plate current, and forward and reverse power output for both bands.
The system occupies a 6 feet tall rack that is on wheels.  Included is a complete working 50 MHz RF deck and a partial 144 MHz deck as well as six, working spare tubes along with complete schematics for the 50 MHz System.
The 50 MHz requires only one watt to drive to over 400 watts, I have run the amp up to 500 watts.  The 144 MHz Amplifier requires only two watts of drive for 350 watts of output power, I have run the amp up to 425 watts.  The amplifiers are spectrally pure and checked with a spectrum analyzer.  They have also passed the test of locally demanding hams under contest conditions for spectral purity.
This is being sold to make way for a new full power amplifier.
I am asking 750 dollars for the complete system.
Here are some Pictures of the amplifier:

k3tuf.com/motoamp/50FrontCloseup.jpg

k3tuf.com/motoamp/144FrontCloseup.jpg

k3tuf.com/motoamp/FrontClosedRack.jpg

k3tuf.com/motoamp/FrontOpenRack.jpg

k3tuf.com/motoamp/MeterCloseup.jpg

k3tuf.com/motoamp/PSFrontCloseup.jpg

k3tuf.com/motoamp/PSRear.jpg

k3tuf.com/motoamp/RearOpen.jpg




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