[Boatanchors] FS: Skywalker 500 HF Amplifier AND a 50 Amp power supply

Bry Carling AF4K bcarling at cfl.rr.com
Thu Dec 17 07:41:13 EST 2015

FOR SALE:  Skywalker 500 HF Amplifier

This is their later model amplifier...

 * 500W output 160-10M 12 VDC power required - but really likes 13.8 V DC
* Power output: SSB 500W PEP
* CW/FM 500W (at 50% duty cycle)
* Drive power for rated output: 20-40 W typical, 35 watts is the sweet spot.
* Frequency range: 1.6-30 MHz continuous
* Max. input current: 75A
* Efficiency: 50-55% avg
* Duty cycle:SSB Continuous voice modulation; CW/RTTY 50%
* Keying: PTT line, 10 mA sinking to ground via RCA jack, RF sensing. Works FB with all 
adjustable 100 watt class rigs.
* T/R switching time: 20 mS
* Operating class: AB with separate regulated bias circuits for each module
* Modes supported: SSB/CW/RTTY/AM/FM
* Thermal protection: 130 F limit switch, auto reset
* Cooling: Two 120 mm muffin fans on heatsink and one 60mm muffin fan internal
* Metering: Collector current for each module.
* Transistors: 4-2SC2879
* Input/Output Impedance: 50 ohm unbalanced, VSWR 2:1 max
* RF connections: SO-239 sockets on rear
* Power connections: 3/8" Dia. bolts for + and -
* Dimensions: 6.5"H x 12"W x 7"D

Looks to be new and unused, but will sell as used. Covers the HF amateur bands in two 
switchable ranges. The circuit is the same as AN-762 from Motorola and is very similar to the 
500 watt amp by MFJ using the same 2SC2879 transistors. New price was around $600.00 
for this powerful amplifier. Used ones have sold in the range of $385.00 - $550.00 - this one 
is far less.

I know this is not for everyone, and it could use some extra RF filtering, but it does work and 
is a nice heavy duty 500 watt ouput HF amlifier at a great price.

Available for $250.00 FIRM plus shipping. 

ALSO available - ASTRON RS50M power spply in excellent working condition. 13.8V DC at 
50 amps! Ideal for this amplifier. Will sell for $189.00 FIRM plus shipping.

Pictures and details available at:


73 - Bry Carling, AF4K

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