As some of you will know I am have been repairing an old 1950s valved radio set.
I had a bit of a shock today, and before you asked I did not touch “B+ (HT)”, I had bought the radio even while the sellers at the shop said that it was broken.
The prejudice relates to the on off switch, I had thought that the switch was broken as I had needed to bypass it to power the radio up. These days most on off switches on audio gear are part of the volume control. A person turns the volume control clockwise to operate a switch.
I tried in vain to turn on the radio this way, while I was taking the radio out of the wooden case to do some work to improve the electrical safety on it (replacing a very old power lead and some other pre PVC mains wiring) I found that the power switch is a push / pull button on the same shaft as the volume control.
I checked the switch with a ohm meter and found it still worked, so I wired the new mains lead via the switch to the mains transformer of the radio. I then found to be delight that the radio worked, I have already been able to tune into some broadcast stations.
It is important to avoid being blinded by our past experiences to something which is different, I am quite glad that the shop wrongly labeled the radio as broken. I have enjoyed working on the radio (wireless) set. I will post photographs of the radio soon.