RE: What to do with 412 volts

Posted by Eli Duttman (A) on March 8, 2017 at 18:32:57

In Reply to: What to do with 412 volts posted by BofService on March 8, 2017 at 17:28:26:

I'm inclined to agree with the choke I/P assessment.

A stereo amp is possible, if you go SE. "Fixed" bias, UL mode, KT88 "finals" will get you a fair amount of O/P power. While a little "shorter" primary impedance would be nice, Edcor's CXSE25-2.5K O/P trafo seems to be a possibility.

Use a 5R4 to rectify the 500-0-500 winding and a 5AR4 to rectify the 235-0-235 winding. I'm very dubious about those 5 VAC windings feeding 300Bs. IMO, it's $ to donuts that the vintage trafo was intended for multi-grid O/P tubes. Notice that both suggested vacuum rectifiers draw 2 A. of filament current, which will be safe. Increase the final reservoir capacitance in the LCLC filter.

Phasing up and connecting the 2 6.3 VAC windings in parallel could give you enough current for the KT88 heaters. Get something low cost from AnTek for small signal tube heating.

Eli D.

Edcor CXSE25-2.5K Transformer (Open in New Window)

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Follow Ups Full Thread

Topic - What to do with 412 volts - BofService 17:28:26 03/08/17 (20)

RE: The lack of a heater CT is not much of a problem - DAK 19:37:03 03/09/17 (0)

RE: What to do with 412 volts - megasat16 11:53:09 03/09/17 (0)

RE: Are these military potted trannys? - DAK 08:45:49 03/09/17 (10)

RE: Are these military potted trannys? - BofService 11:01:23 03/11/17 (3)

RE: Does it have military markings - DAK 11:05:37 03/12/17 (2)

RE: Does it have military markings - BofService 12:40:44 03/12/17 (1)

RE: Does it have military markings - DAK 14:39:24 03/12/17 (0)

RE: Are these military potted trannys? - BofService 15:30:49 03/10/17 (0)

RE: Are these military potted trannys? - Eli Duttman 18:40:26 03/09/17 (2)

RE: Are these military potted trannys? - BofService 16:05:21 03/10/17 (1)

RE: Are these military potted trannys? - Eli Duttman 17:41:03 03/10/17 (0)

RE: Are these military potted trannys? - Tre' 18:13:53 03/09/17 (1)

Unfortunately, i never collected them - DAK 18:41:53 03/09/17 (0)

Cart before the horse - drlowmu 19:53:33 03/08/17 (0)

RE: What to do with 412 volts - Eli Duttman 18:32:57 03/08/17 (0)

RE: What to do with 412 volts - hifipaul 18:17:44 03/08/17 (1)

RE: What to do with 412 volts - BofService 18:22:46 03/08/17 (0)

125mA will get you one channel - Chip647 17:46:02 03/08/17 (2)

RE: 125mA will get you one channel - BofService 18:13:57 03/08/17 (1)

RE: 125mA will get you one channel - drlowmu 19:58:35 03/08/17 (0)

Follow Ups

RE: What to do with 412 volts - Eli Duttman 18:32:57 03/08/17 (0)

RE: What to do with 412 volts

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