14-08-2015, 04:18 PM
This project is now pretty much finished. The output valve anode is now measuring around 275 volts and the series resistor is now 220 Ohms. The GB bias R13 (I think) showed a bit more voltage. The sound quality is surprisingly good. I mean, very impressive. People don't realise how good they had gotten the audio sound even by 1950.
Does anyone have an idea about safety regarding the HT wire to the Smoothing Can? What I finally did was to insulate the 220 series resistor in heat shrink. I then tied it to a thick cable so the whole thing is wrapped in a red heat shrink tube. What I wouldn't like to see happen is the HT wire ever coming off the HT smoothing can and contacting any part of the chassis. So far as I can see, if it did happen the wire would pop upwards and away from the chassis but even so..... I wonder if this ever happened to anyone? I could try taping the wire in such a way as if it did ever come off it wouldn't budge too far??
I was also thinking of a quick blow fuse. Maybe 1 amp? Possibly even modified to fit a plug?
Apart from that it seems O.K. I find it sounds better if there's some earth connection to the earth wire.
Does anyone have an idea about safety regarding the HT wire to the Smoothing Can? What I finally did was to insulate the 220 series resistor in heat shrink. I then tied it to a thick cable so the whole thing is wrapped in a red heat shrink tube. What I wouldn't like to see happen is the HT wire ever coming off the HT smoothing can and contacting any part of the chassis. So far as I can see, if it did happen the wire would pop upwards and away from the chassis but even so..... I wonder if this ever happened to anyone? I could try taping the wire in such a way as if it did ever come off it wouldn't budge too far??
I was also thinking of a quick blow fuse. Maybe 1 amp? Possibly even modified to fit a plug?
Apart from that it seems O.K. I find it sounds better if there's some earth connection to the earth wire.
