GU-50 power amp

[W3SLK]

Hey Tolly, I do some repair work for a local music house nearby. I'm toying with the idea of building a neat guitar amp based around an 829B, (There is a Russian equivalent but the number escapes me) I figured I could get ~45-55 watts out in AB1. I may consult with you on this when I get the project up and running. BTW, Walnut Creek is my old stomping grounds. I was station at Mare Island, Vallejo when I was in the Navy.

[WA1GFZ]

Hey cut away a little of the spark plug boot and run packard 440 wire, with spark plug boots. The high voltage lead will contain the high frequency transients to the inner conductor thus improving high frequency response. I know packard 440 wire in my big rig gives me that spank second gear feeling.
There must be a marketing angle here somewhere.

[wavebourn]

Hey Tolly, I do some repair work for a local music house nearby. I'm toying with the idea of building a neat guitar amp based around an 829B, (There is a Russian equivalent but the number escapes me) I figured I could get ~45-55 watts out in AB1. I may consult with you on this when I get the project up and running. BTW, Walnut Creek is my old stomping grounds. I was station at Mare Island, Vallejo when I was in the Navy.

You are welcome Mike!

Use GU-50, it is better than GU-29 for audio frequencies!

[WU2D]

Wavebourn,

I like the old fashioned tube regulator. Variations on this circuit have been published all over including in the Handbook. I have made them with 6AU6 / 12AU6 error tubes and single 6AQ5's, 12BY7's, 6CL6's, triode connected for up to 120 mA. This is usually just the ticket for a VFO or circuit that wants a little more than what a single voltage regulator tube can do.

The filaments must be isolated (floating) because the tubes are operating quite a bit above ground. A small fill transformer works.

With a pot for R1 and R2, you can make a dandy 100 - 250 VDC supply.

Mike WU2D

[wavebourn]

Thank you Mike; I have nearly the same but cheaper (my FETs instead of your tubes), though a gas discharge regulator is still used. It serves an indicator's purpose as well,

I recently bought bunch of Russian SG-2S, SG-3s, SG-4S regulators. Some glow orange, some glow pink... Nice! 

[WU2D]

I have a few odd regulator tubes from test gear. Some of these are filled with lets just say "rare" gasses and compunds that you would not want to come in contact with. Many unusual performance enhancements could be had through lacing these tubes with radio active trace elements. 

Mike WU2D

[wavebourn]

Mine contain argon, neon, helium. Innocent neutral gases.

[The Slab Bacon]

Mike,
       that regulator circuit looks like the one from ny 1963 arrl handbook, except that they used 807's for the cathode follower / pass regulators. I have a very similar circuit for the screen regulator in my 4X1 transmitter.

                                         The Slab bacon

[WU2D]

I use one on a command transmitter where the VFO is drawing power. Add the final's screens and you really need more current than you can do with a raw VR tube. The interesting thing about the circuit is about anything can be made to work as a pass device as long as it has the current rating and you can parallel up tubes. It is lEEEENEEEAR however and they do get warm. But who goes around squeezing hot 6AQ5's anyway?

Mike WU2D