UK Vintage Radio Repair and Restoration Discussion Forum - View Single Post - Suspect Mains Transformer in 1930s Radio P.S.U.

'LIVEWIRE?' · 20th Apr 2018, 8:32 am

The Insulation Tester I use is a TMK TEM1555B, which I bought at the NVCF a couple of years ago. In the Megohm setting it applies 500v to the item under test, displaying the result on an analogue meter. As previously noted, when testing the transformer, readings show as >200Megohms (rising to almost infinity after a second or two). As this, admittedly old, instrument was designed as an insulation tester, and is in good working order, I'm inclined to accept it's readings. Regarding the lamp limiter, I built and wired it, and have re-checked my wiring. It may get re-built into a wooden or plastic box if and when I can find the time, but although it's presently on a wooden baseboard, it is correctly wired. The probes & leads are new Cat.III ones which I bought from CPC maybe a year ago. Each is fused @ 500mA. I mentioned all this in a thread about the TEM1555B a while back.

20th Apr 2018, 8:32 am	#44
'LIVEWIRE?' Rest in Peace Join Date: Mar 2006 Location: N.W. Oxfordshire(Chipping Norton) Posts: 7,306	Re: Suspect Mains Transformer in 1930s Radio P.S.U. The Insulation Tester I use is a TMK TEM1555B, which I bought at the NVCF a couple of years ago. In the Megohm setting it applies 500v to the item under test, displaying the result on an analogue meter. As previously noted, when testing the transformer, readings show as >200Megohms (rising to almost infinity after a second or two). As this, admittedly old, instrument was designed as an insulation tester, and is in good working order, I'm inclined to accept it's readings. Regarding the lamp limiter, I built and wired it, and have re-checked my wiring. It may get re-built into a wooden or plastic box if and when I can find the time, but although it's presently on a wooden baseboard, it is correctly wired. The probes & leads are new Cat.III ones which I bought from CPC maybe a year ago. Each is fused @ 500mA. I mentioned all this in a thread about the TEM1555B a while back.