I'm thinking of building a HF amp using something with either a Russian 4cx400 or 4cx800 equivalent. But I'm not sure on the best way to do a tuned input. Any suggestions or good links I should read up on?
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Tuned input for Tetrode
- Thread starter Crusher
- Start date
http://www.wb8erj.com/813mainsch.htm
Crusher you can lookat this and see what you think.
the GU5B amp build turned out great thanks for the links on the dayton blowers.
Crusher you can lookat this and see what you think.
the GU5B amp build turned out great thanks for the links on the dayton blowers.
Sweet. Interesting info, thanks for the link. I may try something like that. Man 7.5 turns with 1" I.D. That's a decent amount of inductance. I'm thinking 1.5-2uH.
Nice. Sounds like ya got her purring like a kitten. I'm hoping to put this together over winter. Slowly piecing and picking up parts along the way.
The amp seems to be doing ok, uses a Pole Pig for a B+ tr. huge heavy darn thing but al the amps the amp will ever need for the B+.
I know what you mean by parts and pieces. I dug DEEP into the junk box to finish this russian tube build.
Price of new parts and pieces makes building an amp more expensive than buying a commercial made.
Sure is fun putting those parts and pieces together and watching it work.
I know what you mean by parts and pieces. I dug DEEP into the junk box to finish this russian tube build.
Price of new parts and pieces makes building an amp more expensive than buying a commercial made.
Sure is fun putting those parts and pieces together and watching it work.
BJ radionut
Supporting Member and 6m addict
That transformer will make a hernia quick. PITA to pick up.
It may look like the blower motor is installed wrong but the GU5B hangs upside down as most Russian tubes do.
The heat from that tube is tremendous. I was concerned about plate and grid meters and the plastic melting or warping. No metering on the RF deck.
I just protected the B+ voltage at 2 amps. tube specs are 2.5 amp. at 5000 VDC.
Plate current is fuse protected similar to the DRAKE L4B cathode fuse mod.
OFF topic for the thread but BJ did ask for pics.
It may look like the blower motor is installed wrong but the GU5B hangs upside down as most Russian tubes do.
The heat from that tube is tremendous. I was concerned about plate and grid meters and the plastic melting or warping. No metering on the RF deck.
I just protected the B+ voltage at 2 amps. tube specs are 2.5 amp. at 5000 VDC.
Plate current is fuse protected similar to the DRAKE L4B cathode fuse mod.
OFF topic for the thread but BJ did ask for pics.
Last edited:
BJ radionut
Supporting Member and 6m addict
HOLY ARC-SHIELD BATMEN
FIRE IN THE HOLE!
Sorry for off topic BUT...inquiring minds had to know
All the Best
gary
FIRE IN THE HOLE!
Sorry for off topic BUT...inquiring minds had to know
All the Best
gary
I am assuming that when you say an HF amp you mean the entire HF range 160-10m. You can make a simple Pi section using solenoid inductors or toroids and switch one in for each band either with a DPDT switch or separate relays. that what is usually done and is what I plan to do WHEN I build my amplifier.....which I may get a start on this winter.
Ummmmm.......not quite what I would like to see for wiring a high voltage supply however I do have only one thing to say. For Christ's sake don't shove that thing back against the wall and keep your hands, children, small pets, and large dust bunnies away from there!
Here is a Google link to a lot of ideas
https://www.google.ca/search?q=ampl...=L9E1VOPREoPC8QH_zoGQBg&ved=0CCMQsAQ#imgdii=_
and here is one specific.
http://gs35b.com/input/
https://www.google.ca/search?q=ampl...=L9E1VOPREoPC8QH_zoGQBg&ved=0CCMQsAQ#imgdii=_
and here is one specific.
http://gs35b.com/input/
Shields/ cabinet covers were removed for pictures.
The op wanted the PS to be able to supply B+ to other decks in the future.
The plan is to re locate the PS permanently in his shack as a stand alone HV PS.
SO this is a temporary cabinet to allow me to move that beast around using the casters of the cabinet.
The op wanted the PS to be able to supply B+ to other decks in the future.
The plan is to re locate the PS permanently in his shack as a stand alone HV PS.
SO this is a temporary cabinet to allow me to move that beast around using the casters of the cabinet.