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[Amps] Various Amps For Sale Part II

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Subject: [Amps] Various Amps For Sale Part II
From: "John Farber" <>
Date: Sun, 17 Dec 2006 19:11:47 -0000
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Here's a bit more info on my amplifiers for sale:

I need to clean the shack (and the garage). I have several amps and 
in-progress amps I'd like to sell at very reasonable prices if there is 
interest in them.
1. Pair of 3-500 Z HF or dedicated 6 m amp. HB conversion amp I built, using 
a Hallicrafters HL-33 chassis, pair of 3-500Zs. Separate, outboard HD HV PS 
running 3.5 kV, with step-start for the HV. The amp deck has a step-start 
ckt for the filaments as well. I got 1300 W out when driving with 100 W 
exciter, 1500 W out when driving with about 150 W in (a bit less on 160 and 
10 m), or typical for a pair of 3-500Zs. I built it originally as a 160-10 m 
HF amp and used it for 15 years in that configuration. I then bought an 
Alpha 99, so I decided to convert my old HB amp to a dedicated 6 m amp. I 
got as far as removing the HF tank, winding a new filament choke, and 
started on the output circuit when I found a HB 6m amp and bought it. So now 
I have my old amp just sitting. I still have all the tank parts, so if 
you're an amp builder type you could put the tank ckt back in and have a 
nice 160-10m linear.
2. HB HF amp I bought and am no longer using. Single 4-1000A, pair of 
Jennings vac-variables in the tank. Big box chassis, very well made. 80-10, 
uses an outboard PS in a 3-ft high roll-around rack. Big Variac to adjust 
the HV. Step-start circuit. Big oil-filled filter caps, a serious amp. It 
blew the original HV xfmr and I replaced it with a Peter Dahl unit, will do 
close to 1500 W out as configured but I believe higher B+ is needed to 
really make the amp "sing". Again, if interested, we can discuss price. Both 
units are heavy, so they must be
picked up in the Santa Cruz Mtns. area near San Jose, CA.
3. 6 meter unfinished project amplifier deck. I also have an unfinished 
dedicated 6 m amp deck, using a single 4-1000A tube, with the Eimac cast 
aluminum "air system socket". I has an onboard
filament xfmr, but I used another HV supply for another amp to test it, so 
you would have to come up with the HV supply and a blower. It is still in 
rather crude "prototype form" but the input matching circuit is installed 
and works, the tank circuit is installed and works and uses a neat little 
Jennings vac variable cap. They both resonate well and provided a good match 
to my exciter and into a 50 ohm dummy load. I originally built it to be a 
tetrode amp, powered by my FT-726R (10 W output on 6m). I was able to get it 
to amplify, 8 W in gave me 800 W out, BUT I never cured the problem of
oscillation. Wired as a tetrode, it also has a +900 V screen supply, and I 
suspect that needs better regulation. The design was printed in QST and was 
from a W1 if I remember, (W1QJ or some such call) I probably still have the 
article I built it from, if not, I'm sure you could get your hands on a 
reprint. You could just convert it to g.g. triode mode and drive it with a 
100 W exciter. It's
just sitting on my shack floor, so I'm willing to part with it for a 
reasonable (low) price. It's about 1 square ft by 17 inches or so, with a 
good tube. I even have a couple meters to go with it. I never got as far as 
making the meter front panel. I can take photos if you like. I'd like to 
sell it, as I've moved on to other projects. This could be shipped in two 
boxes, the deck in one and the tube in the other.
I could take photos of some of these (the roll around 3 ft PS rack is buried 
in the garage). We can discuss price if you are interested.
Thanks, John,

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