Welcome • User Guide
ToS • Privacy • Canary
Donate • Bugs • License

©2024 Poal.co

391

This is a 1960s external power supply that was very common. It supplied +830 Vdc, +300/+250 Vdc switchable, -130 Vdc bias, adjustable ~50 Vdc bias, +6 Vac filament, +12 Vac filament via a crazy 11-socket plug. It featured external on/off, a "circuit breaker", and could optionally fit inside the company's speaker enclosure.

Older poaler bears (@Owlchemy) will recall fondly the Heathkit phenomenon, whereby inexpensive (relative to others on the market) kits were made for adults and older children to put together themselves! Think of it... soldering, deadly voltage... could never do it today.

As with any old electronics, as @sporkulon can attest to, capacitors will probably be bad, and given the price to replace, worth doing. In the case of this power supply, it was so common that a couple folks have made printed circuit board replacements for the direct point-soldering method of circuit construction, and everything fits in a smaller space (while still using the transformer, choke (inductor), switches, and mounting points.

  1. Comparison of my grandfather's work vs. mine (picinfinity.co) (he had lead solder probably!) soldered all diodes, resistors, capacitors to the PCB
  2. Old unit didn't have the cover that came with it; wasn't a big deal before but now there would be exposed 800 Vdc so good idea to get a cover off eBay (picinfinity.co) and spruce it up (picinfinity.co) with some matching paint.
  3. Hardest part was doing the point-soldering of old wires to the underside of the PCB; several needed extensions. OLD (picinfinity.co) NEW (picinfinity.co)
  4. Outside view, OLD (picinfinity.co) NEW (picinfinity.co)
  5. Finished, with cover (picinfinity.co)

I hereby declare this as the coolest thing any of us faggots did today

This is a 1960s external power supply that was very common. It supplied +830 Vdc, +300/+250 Vdc switchable, -130 Vdc bias, adjustable ~50 Vdc bias, +6 Vac filament, +12 Vac filament via a crazy 11-socket plug. It featured external on/off, a "circuit breaker", and could optionally fit inside the company's speaker enclosure. Older poaler bears (@Owlchemy) will recall fondly the Heathkit phenomenon, whereby inexpensive (relative to others on the market) kits were made for adults and older children to put together themselves! Think of it... soldering, deadly voltage... could never do it today. As with any old electronics, as @sporkulon can attest to, capacitors will probably be bad, and given the price to replace, worth doing. In the case of this power supply, it was so common that a couple folks have made printed circuit board replacements for the direct point-soldering method of circuit construction, and everything fits in a smaller space (while still using the transformer, choke (inductor), switches, and mounting points. 1. [Comparison of my grandfather's work vs. mine](http://picinfinity.co/d/c4247ab5-e3e9-4ff7-855a-07bb4ccd231f.jpg) (he had lead solder probably!) soldered all diodes, resistors, capacitors to the PCB 2. Old unit didn't have the cover that came with it; wasn't a big deal before but now there would be exposed 800 Vdc so good idea to get a [cover off eBay](http://picinfinity.co/d/6baf1c5a-14d9-43c5-b89e-3d4d5018f1f5.jpg) and [spruce it up](http://picinfinity.co/d/32a46305-5c04-4384-a717-361d85a2f602.jpg) with some matching paint. 3. Hardest part was doing the point-soldering of old wires to the underside of the PCB; several needed extensions. [OLD](http://picinfinity.co/d/773d32d2-e4d2-45c0-9f52-70577a5f49a7.jpg) [NEW](http://picinfinity.co/d/d8267eec-c9bd-4615-bad6-b6ce873a42ae.jpg) 4. Outside view, [OLD](http://picinfinity.co/d/fe9df325-40ee-4d5a-89cb-e8756f522906.jpg) [NEW](http://picinfinity.co/d/38211039-a7a4-44ed-80c4-7d3462c2687f.jpg) 5. [Finished, with cover](http://picinfinity.co/d/11591e15-c161-4b25-8fd8-444629886522.jpg) I hereby declare this as the coolest thing any of us faggots did today

(post is archived)

[–] • 2 pts

That's awesome man. I didn't know your grandpa was into that too. Family tradition

[–] • 2 pts

I figured since I inherited the stuff, it only stood to reason to at least learn enough to get his old callsign and keep it in the family

[–] • 1 pt

Very cool, quite a respectable rebuild you've done. Looks very professional. Also glad to see you dumped those ancient caps ... as they age they leak some nasty PCB (polychlorinated biphenyl) stuff. The new circuitry looks awesome ... you deserve a big pat on the back, your Grandpa would be proud!

[–] • 1 pt

You could try resurrecting those old caps with the saline solution low voltage trick. They don't look leaky or bulging and they don't make them like they used to. Love the point soldering with old parts. Are you going to do that crossword and sudoku?

[–] • 1 pt

I definitely am not getting rid of them. There was a safety reason to replace; the old style had the anode directly on the shell (thus the black cardboard).

I love words, but can't stand crosswords.

Sudoku - I solved a couple once, and then it got repetitive. lol

[–] • 1 pt

Another thought. You could try and source switching power transformers and go all out. Those old linear types suck the juice and make heat like no tomorrow. Just replaced a 16 volt transformer in a 1955 GE tube radio and it went down to 72 degrees operation @ 69 degrees ambient from 147 degrees, the thing ran so hot it had dried up the vent holes carved in the wood.

[–] • 1 pt

Interestingly, a lot of the old radio equipment with crystal oscillators are designed to operate hot, to avoid temperature variations from affecting the frequency stability & noise. The oscillator is built into a purposely hot "oven" part of the radio. Idea is if it's ALL really hot, then variations in ambient don't affect measurably affect the signal