Hey Folks,
Is anyone aware of a rectifier tube that can run off the same supply as other tubes in a circuit? I've got a few surplus transformers with no 5V taps. Thanks...
Is anyone aware of a rectifier tube that can run off the same supply as other tubes in a circuit? I've got a few surplus transformers with no 5V taps. Thanks...
How much B+ current do you need? The Locktal based 7Z4 and the 9 Noval (9 pin mini) based 6CA4/EZ81 are both good for 100 mA. DC and they have respectable PIV ratings.
Damper diodes. Though they eat alot of current.
Another option would be to burn it down with resistors.
There may H-K considerations mandating they get their own winding.
Another option would be to burn it down with resistors.
There may H-K considerations mandating they get their own winding.
i'm going to use some 6ay3's in my amp. they have annoying and hard to get "novar" sockets but fortunately triodeelectronics stocks the sockets for reasonable prices. you're bound to find some 6ay3's on ebay, and those are just a few that could work. triode also stocks (the last time i checked) the oddball 6v3 rectifier tube, good for like 850mA and its single cathode is in a top cap 🙂. magnoval socket for that one. i got four for a buck each, hopefully triode hasn't realized the potential and raised the price.
astouffer said:
I didn't think anybody else had discovered those 😉
The 6BY5GA is rated for both damper and rectifier duty, when you look at the Sylvania datasheets.
Best regards,
Mikkel C. Simonsen
I have a few of these. I tried one once, and it blew up. Maybe it was just bad, I'll have to try another. Maybe they just don't like a 47uF input cap.
I KNOW that an 0Z4 doesn't like a 47uF cap. They are picky about the load current. 30 mA minimum, and 100 to 120 maximum, depending upon the version. The glass ones have a cool purple glow.
I have a few zillion 6AX4's. They are old damper tubes with octal sockets. They seem to take all of the abuse that I throw at them, including a 47uf input cap and 480 volts worth of transformer (B+ of 600V with hybrid bridge).
Thats nothing 😉 I used to use two photo flash caps in series as the first cap after a 5U4 or even 5Y3. Those caps were 160uf at 330v. Even had a large bank of them in a SE 211 amp until one blew up. It left quite a mess of paper and funny white smoke. The only tubes that ever arced over were those flat top 5R4s, but of course now I know better.
tubelab.com said:
The datasheet mentions a small value (around 8µF) as typical, so it probably won't like 47µF. I use the 6BY5GA in a choke-input supply, so I don't have that problem...
Best regards,
Mikkel C. Simonsen
I got a few of those surplus. They are supposed to be rugged enough for a B52 bomber. They looked like Chinese fireworks in my 845SE. After the caps charged up and the sparks subsided, the 5R4's had more voltage drop than any 5AR4. Shuguang and Sovtek 5AR4's work fine in that amp.
The only data I have is in a 1963 vintage RCA tube manual. There is no mention of cap value.
The "potato masher" 5R4 used in B52 bombers can take 20 muF. filter caps. All the other 5R4 variants can take only 4 muF. filter caps.
The 5R4 and 5AR4 are at opposite ends of the forward drop spectrum. With the full 250 mA. draw, the forward drop in a 5R4 is 67 V.
TDSL 5R4 page here.
5R4GYB data sheet here.
5R4GY data sheet here.
The 5R4 and 5AR4 are at opposite ends of the forward drop spectrum. With the full 250 mA. draw, the forward drop in a 5R4 is 67 V.
TDSL 5R4 page here.
5R4GYB data sheet here.
5R4GY data sheet here.
tubelab.com said:
The Tung-sol datasheet also mentions 8µF, but no maximum.
http://frank.pocnet.net/sheets/127/6/6BY5G.pdf
Best regards,
Mikkel C. Simonsen
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