01-05-2016, 05:45 PM
Refitted the mains transformer, wired it correctly! Screen left O/C.
Run up and it works, good reception on all 3 bands so its not that bad.
Checked the audio coupling cap, only +1 volt on the output valve grid, not bad. Shorting the anode of the last IF valve put the HT up by 4 volts so changed the cap to be on the safe side. It tested out OK at low voltage on the DVM at over 200M Ohm but on the Chinese magic box it was reading 11.76nf instead of 10nf so it is probably slightly leaky. All the rest of the Sprague caps check OK on a quick test and the set is working well so time to quit looking for problems. They are 1000v rated, best bit of the set probably!
Alignment seems to be OK, leave it alone. Run for a few hours with workshop output transformer and speaker lashed in and all seems to be good.
Will need to refit into the cabinet to check the Radiospares output transformer and speaker. In view of the lack of problems with the output valve current, it is a puzzle as to why this was changed. I think I will fit another spare transformer and save the Radiospares one as it is multi tapped and will do a push pull output too.
I will need to find one with the correct ratio if I can find out what that may be for a PEN45 valve, no doubt someone will tell me soon!
Boater Sam.
