Any 9- pin rectifier tubes with separate cathodes?

[Lingwendil]

Are there any rectifier tubes in noval base with separate cathodes? Even individual diodes would work. I'm going to build a full-wave vaccuum rectified psu, and was looking for tubes suitable for this use.

[Arnulf]

You don't need separate cathodes for FW rectifier unless your transformer lacks central tap. Normal FW rectifiers such as EZ80/81 have common cathode and two separate anodes which connect to both ends of the secondary while cathode connects to CT.

But if you insist, there are quite some diodes avaliable in noval version with top caps (check out EY8x/PY8x types).

[Bandersnatch]

hey-Hey!!!,
WE 412 has two independant diodes. As pointed out, a single cathode is fine; consider the octal directly heated types like 5U4...no separating that cathode between two diodes. In any case, with your full wave( or even a hybrid bridge ), the tube diodes are fine sharing the cathode...look at the schematic; even with SS the banded end are together at the positive output.
cheers,
Douglas

[Ciscokid]

Hi,

Hope I understand your question correctly, have a look at the 6CA4/EZ81.

Regards,
ck

[Tom Bavis]

A quick look at the tube data at NJ7P 's site shows 6853, 12DF5, 26Z5. For the last one, you'll have to fight the radio collectors, as it's used in the military R-390 receiver. If you can use an octal, the obvious choice is 6BY5 - cheap and plentiful.

[Bandersnatch]

hey-Hey!!!,
The Bendix Hy-G-300 series also has a 412 equivalent, type 6754. True +30 second warm-up to conduction time, and not too damn expensive. Given the use, I'd go with 6CA4/EZ81, as I don't think individual cathodes are really needed for the full wave, grounded CT operation.
cheers,
Douglas

[Lingwendil]

This would be for a 280vac 2A transformer without a center tap, but it has two 6.3v 3A, and one 12.6v 1.5A winding. It's an older custom job that was given to me. I'd like to stick with noval, as it's for an el84 design, and I have plenty of the proper sockets. The 6754 and 26z5 look promising, and not terribly expensive for the 26z5. Any places online that carry the 6754? AES only shows a cross reference.

[Wavebourn]

A noval rectifier for 560 VA?

[Lingwendil]

Steady state current will maybe be around 425mA. It's for an AB1 push-pull el84 design with ecc82 concertina phase splitter. Basically like a bevois valley.

[Bandersnatch]

Originally posted by Lingwendil
This would be for a 280vac 2A transformer without a center tap, but it has two 6.3v 3A, and one 12.6v 1.5A winding. It's an older custom job that was given to me. I'd like to stick with noval, as it's for an el84 design, and I have plenty of the proper sockets. The 6754 and 26z5 look promising, and not terribly expensive for the 26z5. Any places online that carry the 6754? AES only shows a cross reference.

You'll need two SS diodes to complete the bridge; 5A/600V Cree SiC Schottky types would be at the top of my list for this app...and it would allow the use of the 6CA4, a high performance IDH twin diode rectifier.

I've found it easier to source the WE 412 than the 6754.
cheers,
Douglas