Do you have GloBar resistors in the UK? These are high cold and go lo
with current. they used to be very popular in TVs over here.

--
Thanks & 73
Hank WD5JFR
"Highland Ham" wrote in message
...
The only big iron guys I know are now retired or dead.
And the companies I've dealt with that make that stuff
tend to have very little engineering staff, not much new
going on, (other than some efficiency improvements from
amorphous cores) they just crank out the product in cook
book fashion. I think nuances of it may soon be a lost.

Yes lams are going the way of the dinosuars. Maybe that's why they
cost so much looky the price of a good audio output transformer for a
tube audio amplifier and they go up to at least 20Khz.

Your other option is to figure out some clamping arrangement so that
the
laminations are held close and tight.

Yes I think I will put together a vise of sorts. Custom made to fit
the transformer.
==============
Followed this thread with great interest .
Reason : I have an Astron RS-50A , 13.8V -50 Amperes unit for
220V-AC input which is buzzing heavily. Upon switch-on the group
circuit breaker in the house sometimes trips due to the high switch-on
current surge . This can be overcome by adding a soft start circuit
which initially puts a say 25 Ohms-50Watts resistor in series with the
primary transformer winding ,shorting this resistor after a second or
so.

However I fear that the main reason for the buzzing is that the
transformer (of US origin) was designed for 60 Hz ,whereas here in the
UK (like in all European countries ) the supply frequency is 50 Hz.
Can someone on this NG please confirm/reject my suspicion.

Another possible reason could be that the cabinet sheet metal which is
very close to the transformer is vibrating (transducer effect) .


TIA for any constructive advice/opinion

Frank GM0CSZ / KN6WH