The manual and associated schematic indicate no tubes in the power supply.
Anode rectification is from a half-wave rectifier (typical in those days for low current application)
SNIPPET FROM THE SERVICE MANUAL
Anode rectification is from a half-wave rectifier (typical in those days for low current application)
SNIPPET FROM THE SERVICE MANUAL
I once bought some small piece of test equipment at a yard sale. Inside was a bumblebee cap of just the right values, er, stripes - I think it was the correct one for the tone control on a certain Gibson guitar. I sold it on ebay for $50. For a cap. Easiest pack for shipment $50 sale yet.
(I can see WOT now, digging through his old component stashes... If the market will bear such price for the genuine article, why let them just sit in the coffee can? Maybe some thinks they can hear the difference in such an application and is willing to pay for it. Or to claim fully restored to original)
I once disassembled an organ. I had a bunch of these "FastCaps" from the guts of it. With a little lightning zap as part of the logo. I always wondered what they were - construction wise - then I sold 'em all. You can guess where...
LOL!
Matter of fact, I just yanked out a 0.047u bumblebee cap out of an old AM tube radio. (1954 Motorola 53X)
This cap was between the AC line (after the switch) and chassis ground.
Once removed, it went STRAIGHT into the trash can. 😉
I don't save crap like that, nor would I even sell it to someone.
in the full schematic you posted there is a bridge rectifier in the heater supply circuit, but the hv circuit is half-wave.
The separate one is full wave tube rectified. Not sure what its from.
A friend actually called Sid Smith,
on the phone.
Talked to him for a few hours.
Designed his own amplifier, after that.
on the phone.
Talked to him for a few hours.
Designed his own amplifier, after that.
it may be my preference together with specs, which should be considered on time in each team.
If you give me the details of what you want to dock, I will tell you.
You mean this ?
It is just a sketch of a full wave rectification with two vacuum diodes.
Attachments
I thought that sketch belonged to the Fisher KX200 because you attached it below, post 99, cleared up, thanks.
That's exactly what I meant!
It seemed to me that a cathode was missing ..... there would be a double triode, right?
This memory of mine, I will have to send it to review .....
😀
It seemed to me that a cathode was missing ..... there would be a double triode, right?
This memory of mine, I will have to send it to review .....
😀
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regarding emulating Z of old power supply electrolytic capacitors, I was told by S. Bench to use a 100uH choke with dcr 5-10 ohms.
- will assume say a 1A hash choke with 5 - 10 ohms series resistor would meet that criteria with a tube power amp.
This technique probably could be most useful with vintage guitar amplifiers which are recapped with today's lower ESR capacitors - but might be something to try if one were trying to replicate a vintage Hi-Fi circuit's "tone"
What would be a safe current rating for the choke in preamp use? -how about power amplifier such as 4X EL34?
- will assume say a 1A hash choke with 5 - 10 ohms series resistor would meet that criteria with a tube power amp.
This technique probably could be most useful with vintage guitar amplifiers which are recapped with today's lower ESR capacitors - but might be something to try if one were trying to replicate a vintage Hi-Fi circuit's "tone"
What would be a safe current rating for the choke in preamp use? -how about power amplifier such as 4X EL34?
It is possible to use a (double) triode as a rectifier for B+, but the cathode has to be (one of) the electrode(s) of which the unfiltered B+ is taken because it's the only electrode that is heated (enough), and has its surface treated in a way that it is able to release a substantial amount of electrons to create a meaningfull current.
An example of the use of two 300B's as a full wave rectifier (grid connected to plate):
PCL200
I've been looking at it, it's incredible how many good projects they do (did?) In Japan, thanks for the link .....!
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With OT permission, I don't think this is that off hook anyway .....😉
This was the first HI FI amplifier that I assembled (after assembling several radios, one of them with the famous "Magic Eye", that was fine tuning! I don't remember the code for that tube, could it be 6J5?) I sold it to a friend along with two huge Karlson speakers. Then I went "modern" the transistor!
How much I missed that team, a classic, I know, nothing to write home about, but what a sound next to all the SS trash that even exists today .....🙄
This was the first HI FI amplifier that I assembled (after assembling several radios, one of them with the famous "Magic Eye", that was fine tuning! I don't remember the code for that tube, could it be 6J5?) I sold it to a friend along with two huge Karlson speakers. Then I went "modern" the transistor!
How much I missed that team, a classic, I know, nothing to write home about, but what a sound next to all the SS trash that even exists today .....🙄
