UK Vintage Radio Repair and Restoration Discussion Forum - View Single Post - Hi From Cathy Lissen/Eveready Kenilworth??

cathy_vintage · 7th Sep 2016, 10:49 am

Thanks for recent replies. Yes I have a mains 1kVA isolation transformer and various 'Variacs', so that I can gradually 'wind up' the voltage, after I have isolated the secondaries. I am surprised that the Trader Sheet doesn't quote AC secondary outputs. Always used to ask our 'trainees' How come you can get greater than 240 vac out of a Variac given that the input voltage is measured at 240v? Used to cause some head scratching that one, as they assumed it's just a simple potential divider (which it isn't) ! If I add power resistors to 'load' the output windings, then what is a realistic current to draw to give the Tx a 'bench soak' before proceeding any further ? Adding up the anode currents I was thinking 60 mA for the HT winding or is this too simplistic or excessive? I won't do anything without the blessing of you guys.

BTW my old pal Les, a radio amateur, who sadly passed away a couple of years back, and gave me that NOS audio Tx, used to call transistors 'three-legged-fuses'. He would have been in his element with this radio. He used to go into a shop on Hedon road in Hull as a boy to get his valves tested & in the '70's I remember a lady in that same shop still carried out valve testing as I gather her husband was no longer around.

7th Sep 2016, 10:49 am	#42
cathy_vintage Pentode Join Date: Sep 2016 Location: Willerby, East Yorkshire, UK. Posts: 191	Re: Hi From Cathy Lissen/Eveready Kenilworth?? Thanks for recent replies. Yes I have a mains 1kVA isolation transformer and various 'Variacs', so that I can gradually 'wind up' the voltage, after I have isolated the secondaries. I am surprised that the Trader Sheet doesn't quote AC secondary outputs. Always used to ask our 'trainees' How come you can get greater than 240 vac out of a Variac given that the input voltage is measured at 240v? Used to cause some head scratching that one, as they assumed it's just a simple potential divider (which it isn't) ! If I add power resistors to 'load' the output windings, then what is a realistic current to draw to give the Tx a 'bench soak' before proceeding any further ? Adding up the anode currents I was thinking 60 mA for the HT winding or is this too simplistic or excessive? I won't do anything without the blessing of you guys. BTW my old pal Les, a radio amateur, who sadly passed away a couple of years back, and gave me that NOS audio Tx, used to call transistors 'three-legged-fuses'. He would have been in his element with this radio. He used to go into a shop on Hedon road in Hull as a boy to get his valves tested & in the '70's I remember a lady in that same shop still carried out valve testing as I gather her husband was no longer around.