GS-35b HF Amplifier
by
KB9DB
Bottom View
Click on picture for zoom

Bottom view shows Penta-Labs air socket modified for the GS-35b. The filament choke is a B&W 30Amp, 40uH, #10 AWG wound on a 7 1/2" x 1/2" ferrite rod. Purchased from Surplus Sales of Nebraska, comes complete with mounting hardware. Their part # is (ICH)FC25A. A large ceramic feed-thru insulator carries the B+ to the upper deck. Just below and left is a 50 Watt 36 Volt stud mounted Zener diode for tube biasing. Left of it is a 24VDC relay which switches the biasing zener in on transmit and out on standby to cut off the tube when not in use. The Zener connects to the C.T. of the 12.6VAC filament transformer. Just below is the relays' 24VDC power supply consisting of a Stancor 24VAC transformer and full wave bridge rectifier. The positive (+) lead from the rectifier goes directly to the relay coil, a chassis mounted transistor is in series with the negative (-) lead and acts as a switch on its way to the relay coil. This makes a much cleaner PTT connection to the transceiver. Does the Reflective Orange with Black Letters look familiar? It should...The 1/8 aluminum used in much of this project is a recycled, never used, "MEN WORKING" sign!


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Last Updated: 27 May 2001
Feedback: Paul S. Goble, III, ND2X
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