[Amps] LK-500Z

[Bengt A Jockert]

Hello
Tried to tune my old LK-500Z amp on a WARC-band and had a big bang. Replaced the RF choke but still having problem. Used a variac (took out the tubes) to increase HV slowly to find out where it sparkled. Up to 2,2 kV, no problem but when the primary reaches 220V the fuse blow. Cannot see any arcing but can hear something.
Anyone with experience of similar problems?
73 de Ben - SM6CKU