The AM Forum

Hi all

I have a Henry 2k linear amp with a pair of 3-500Z and it appears the power transformer is history. Here's the issues. I have nothing connected to the secondary windings. When I power it up, all is fine. The primary fuse's don't blow. As soon as I connect the secondary center tap only to it proper connection which goes to the plate current meter it blows the fuse. The center tap is grounded thru the plate meter. I checked the secondary for resistance to ground and it shows about 5K of resistance. I know thats a bad sign and it should have Zero conductivity to ground or the body of the transformer. So.......... it looks like need a new transformer. It's a really weird shape one and I have no idea were to get one?? How about getting it rewound ??  Who can do this for me??


Thanks
john KI4NR

John,

If possible, isolate the transformer from the chassis and see if the problem persists. CAUTION!  DO NOT TOUCH THE TRANSFORMER AT ALL WHEN IT'S ISOLATED FROM THE CHASSIS!  If you want to have it tested thoroughly and rewound if needed contact Gary, WZ1M, he's the man for the job.

Are you sure you don't have a shorted filter cap or rectifier diode?

Rick/K5IAR

sounds like a primary to secondary short. Be careful you might have AC on the chassis. Float the chassis and I bet it comes up. Don't touch it as you may do the INR dance to the floor

there is a resistor in series with the plate meter.
it was fried on mine.

on the 2KD that I have, the power xfrmr is definitely shorted, fried.
I think that it would be fairly easy to hacksaw off one side of the turns and count the turns of the primary and seconday windings, and hand wind it. But since it also has a filament winding it's far simpler to put in a filament transformer and not wind it back onto the new windings - it's harder to get that right than get the B+ +/- 10% compared to the original, imho.

               _-_-bear

Thanks for all your help. The transformer is heading up to Gary WZ1M for a rewind.

73 john KI4NR