04-21-2024, 08:38 PM
Mike;
Thanks for reminding me of your Telefunken thread, I had almost forgotten about that. One thing I will do is check the tubes and see if the UY41 is any good, if not then double silicon diodes it is. I was mostly thinking of using it as it will offer a controlled rise in the B+ voltage rather then an instant on before the rest of the heaters have a chance to warm up. The UY41 only consumes 31 volts at 100 ma, I'm not sure how close I could get with a capacitive dropper, should I chose to eliminate it but maybe? You bring up a good point about the ground reference, I've heard this is also a reason NOT to retrofit a bridge rectifier into an AC/DC set that had a half wave selenium rectifier in it originally, and I think your thread confirms this, at least with regard to that Telefunken.
Regards
Arran
Thanks for reminding me of your Telefunken thread, I had almost forgotten about that. One thing I will do is check the tubes and see if the UY41 is any good, if not then double silicon diodes it is. I was mostly thinking of using it as it will offer a controlled rise in the B+ voltage rather then an instant on before the rest of the heaters have a chance to warm up. The UY41 only consumes 31 volts at 100 ma, I'm not sure how close I could get with a capacitive dropper, should I chose to eliminate it but maybe? You bring up a good point about the ground reference, I've heard this is also a reason NOT to retrofit a bridge rectifier into an AC/DC set that had a half wave selenium rectifier in it originally, and I think your thread confirms this, at least with regard to that Telefunken.
Regards
Arran
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