[Milsurplus] [Boatanchors] 19 Set Power Supply

[Bruce MacMillan]

I think technically the circuit is sound however the unit uses 4 6X5-GT 
valves. Two are used for the receiver B+ at 265v, below the 450v choke 
input filter rating. The HT2 (xmtr) is 540vdc but is divided between two 
cascaded 6X5 full wave rectifiers so each valve handles 270v. The 
heater/cathode rating is 450vdc, above the actual applied voltage. I 
think the main problem is using a 6X5 in the first place. It has a 
reputation of shorting internally and converting solid copper into 
copper ions inside the xfrmr housing.

I bring it up on a variac just to prevent any surge. It hums loud but 
not as noisy as the dynamotor spooling up and there's no delay going 
from rcve/xmit/rcve.

Bruce   ve7mt

J. Forster wrote:
> Mine are not to hand so I can't tell you the S/Ns.
>
> I'm not so sure bringing it up on a Variac is the issue. One of the tubes
> in the HT2 supply has about 300 V, heater to cathode. IMO, that's asking
> for trouble. Silly design.
>
> The main failure mode seems to be arcover in the HT windings of the
> transformer also. I have one mostly reverse engineered and will get one
> rewound eventually.
>
> Best,
> -John