14-04-2017, 07:14 PM
Hi Sam, an interesting unit, I have similar ones but not quite like this. There should be stuff about it on the web.
GB was not normally on this units as batteries lasted a long time and did not give the hum the unit would. Batteries were also adjustable in 1.5v taps.
12 or 18mA max perhaps on the HT.
Rectifier would be copper oxide, usually pretty reliable and could be in a voltage doubler configuration.
Normally a single output voltage and a series of resistors to give the different voltages at the sockets, pretty hit and miss as it depended what was being drawn from the socket. Check with DVM will probably show it way too high.
These often used an LF choke, looks like that HF one has been bodged in.
It should restore OK, but bake the transformer in an airing cupboard for a week or 2, then Megger it. I have a few of these that I've restored and the seem to work quite well.
Ed
GB was not normally on this units as batteries lasted a long time and did not give the hum the unit would. Batteries were also adjustable in 1.5v taps.
12 or 18mA max perhaps on the HT.
Rectifier would be copper oxide, usually pretty reliable and could be in a voltage doubler configuration.
Normally a single output voltage and a series of resistors to give the different voltages at the sockets, pretty hit and miss as it depended what was being drawn from the socket. Check with DVM will probably show it way too high.
These often used an LF choke, looks like that HF one has been bodged in.
It should restore OK, but bake the transformer in an airing cupboard for a week or 2, then Megger it. I have a few of these that I've restored and the seem to work quite well.
Ed
