"N_Cook" wrote in message ...

Owner decided to power up on full 240V mains after being in an English
garage for many years. Worked perfectly before "storage" and well for a
few minutes and then arcing and sparking crackling noise so he switched off.
3 amp mains fuse ok but at half mains on a variac taking about 1 amp
with all valves removed. I'm assuming the excess current draw does not
disappear at 100% mains, I've not tried, but about 1.2 amp at 50% and
not distressing let alone blowing 3 amp at 100% before my powering,
curious? Unusual, for these days, winding pattern,? no magnetising buzz
heard at 50% mains or other any odd noises.
With variac "mains" of 34V ac, secondaries give, multiplying by 240/34,
465V, 6.3V, 5V, ie ballpark values . "HT" is ratioed 27 to 39 V ac wrt
ground, but 27+39 multiplies to 465V .
I've not desoldered the mains Tx primary or secondaries yet, but what
could be the failing in the Tx to give otherwise good scaled outputs.
There is a lot of tar leaked out of the Tx , but that was in antiquity
presumably and normal.
HT caps and o/p tx have been replaced at some time and a dummy load/sp
attenuator added for recording





Insects? Now carbonised?



Gareth.