Posted by Tnuctipun [ 64.12.116.14 ] on February 16, 2005 at 17:44:55:
In Reply to: Re: Silver Lining posted by colinhester on February 16, 2005 at 13:08:31:
Well, I think it is a requirement to have a seperate 2.5 volt TX for the 2A3's. If you are careful with the rest of the filament demand, like using a GZ34/5AR4 rectifier and not too much of the 6.3 for the front end...It ought to run PP 2A3's in fixed bias w/o any trouble.
The core is good for ~70 VA. With 10VA for the rctifier, and 5 VA for the front end, there ought to be plenty left for the plates through the 325 plate taps. I ran a sim with PSUDii with 325vac into an LC filter and got 260V. 50VA at 260V leaves something like 190 mA. We'd only have to worry about copper losses, and these things are rated for operation to 100C/212F ( FWIW, ~140F is enough to cause you apin fairly quickly ). It oughtn't to get that hot.
I took another of their PTX's and ran it over its rating into a cap input filter and it got fairly hot, but not to burn quickly. These guys are conservative enough IMO to run PP 2A3's without smoking.
regards,
Douglas
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