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Author Topic: New Project Itch, seeking opinions...  (Read 2445 times)
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W7SOE
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« on: January 26, 2009, 01:37:17 PM »
I would like to start gathering parts for a true HB project, I have never done one from scratch.  I have sold my HB 813 transmitter, not built by me but it is/was beautiful.  I regret selling it and I think I need to built something as therapy.

First I was thinking of building a full transmitter, also based on 813's but now, given my experience level and time available, I think a linear amplifier is the ticket.  That way the need to build a modulator and modulator PS is eliminated.  It is also a lot smaller.

I have decided to build a grounded grid amplifier based on two 813's.  I chose grounded grid because it doesn't require the more complicated tuned input circuit.  I plan on driving it with my JVII.

I plan on gathering parts over the next months, so far I have a filament choke, filament transformer, and one 813.  I plan on building a PS with SS rectifiers to save space and have the HV controllable with variac..

I have several articles on GG 813 amps.

I would be interested in opinions on these amps in general.  I would also appreciate sources for:

Plate transformer (voltage and current rating desirable?)
Tank coils and cap
bandswitch
antenna load cap

Thanks all.

Rich

W7SOE
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KL7OF
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« Reply #1 on: January 26, 2009, 02:25:43 PM »
Rich.....Winterfest is being held in Mineral, WA the last weekend of this month...All AM  and lots of parts available.   Check out w7jhs website for the info...If you can go ....just post your needs here and someone may have what you need and bring it ...Sorry I will miss winterfest this year..  good luck..Steve
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KL7OF
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« Reply #2 on: January 26, 2009, 02:40:26 PM »
My recommendations......
plate transformer....3-3.5 kv 500 ma. is good but smaller will work   813's like 2400-3000 volts...
tank coil...hand wound of #12-#10 copper wire for low bands ----tubing 3/16-1/4" for high bands
Band switch. as big as you can get..stay away from small wafer types
Antenna loadcap....can be a close spaced receiving type but as with all things bigger is better..
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W7SOE
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« Reply #3 on: January 27, 2009, 03:04:10 PM »
Quote from: KL7OF on January 26, 2009, 02:25:43 PM
Rich.....Winterfest is being held in Mineral, WA the last weekend of this month...All AM  and lots of parts available.   Check out w7jhs website for the info...If you can go ....just post your needs here and someone may have what you need and bring it ...Sorry I will miss winterfest this year..  good luck..Steve

I just got the go ahead to head up to Winterfest this Saturday!   Amazing...

Rich
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KA7WOC
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« Reply #4 on: January 27, 2009, 03:45:15 PM »
Rich,
Get there as early as you can!
Bob
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Bob (aka Boatyard)
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