GS-35B Amplifier For 160 Meters
Built By Bob Briggs, VK3ZL
 
First licenced in 1978, my primary interest in ham radio has always been home brewing and 160 meters. I recently got the opportunity to put together this desk top amplifier using the GS-35B triode. The design is not original although I have included a few ideas of my own. I contacted Tony W4ZT after viewing his page on GS-35B amplifiers (http://gs35b.com) and the success of the project is largely due to his expert advice and encouragement for which I am grateful. My aim was to have a compact but reasonably efficient desk top amplifier which would produce around 1200 watts output. This unit easily fills that aim.The unit weighs over 75 pounds and measures 18 1/2 inches wide by 7 inches high by 18 inches back. I encourage others to try home brewing. It is a rewarding and pleasant pastime. Robert Briggs.......VK3ZL
 

(click the small pictures below to see a large picture in another browser window)

1
Transformer. 1500 Watt CCS core. 1250 VAC.

2
Gathering likely components.

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Setting components out.

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See how they fit into box.

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HT compartment.

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Looks about right.

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Box has been dismantled, panels etched in caustic and reassembled.

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Papst blower and tube in place.

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Coming together.

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Coming together.

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Pi network hardware.

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Cathode compartment with filament choke and B minus line choke.

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Another view of the cathode and filament.

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Filament transformer.

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Getting the hardware in place.

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Selectable zener diodes for bias.

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160 metres tuned Pi network.

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Cathode compartment.

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Grid protection circuit board.

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Completed board for relay trip and indicator leds.

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Front panel, raw state, sprayed with etch primer.

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Front panel lettered and controls mounted.

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Hole for future bandswitch.

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My pet hate, wiring. Front panel to main chassis

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HV supply and grid trip relay

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Step start relay supply and grid trip relay.

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Over all view

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Business end

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Finished front view

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another front view

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Back view showing exhaust

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Front showing air inlets
June 10, 2006 Hamfest      

33
Amp on display at the convention and home brew contest

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First place certificate and new soldering station and driver set prizes

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Closeup of first place certificate

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Restored AR7 at the fest.

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Replica working crystal set built from a book article circa 1906.All the brasswork and the case is home made.For effort I would have judged it the winner.

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Some of the tables

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Some of the tables

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Some of the tables

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Alan

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A few friends at the front door
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June 8, 2006
All images and text used with permission of VK3ZL.
Tony W4ZT
http://gs35b.com
http://w4zt.com