UK Vintage Radio Repair and Restoration Discussion Forum - View Single Post

kalee20 · 2nd Jan 2008, 6:30 pm

I have a Soundmirror tape recorder from 1952 which is still on its original EM34.

The HT is switched off, when set to 'Play' - it is only active on 'Record'. I guess this has helped prolong its life. The wear-out mechanism appears to be poisoning of the phosphor material so it doesn't emit light, as opposed to declining cathode emission.

I'm guessing that reducing the HT would alter the deflection sensitivity, but try it! Otherwise, is it possible to add a timer with push-button which connects the HT via a relay, for a short time (say 2 minutes) when a button is pressed? It means add-on circuitry and a hole for a button - but if the cabinet is a bit ropey then you may not mind.

2nd Jan 2008, 6:30 pm	#2
kalee20 Dekatron Join Date: Feb 2007 Location: Lynton, N. Devon, UK. Posts: 7,088	Re: Magic eye life I have a Soundmirror tape recorder from 1952 which is still on its original EM34. The HT is switched off, when set to 'Play' - it is only active on 'Record'. I guess this has helped prolong its life. The wear-out mechanism appears to be poisoning of the phosphor material so it doesn't emit light, as opposed to declining cathode emission. I'm guessing that reducing the HT would alter the deflection sensitivity, but try it! Otherwise, is it possible to add a timer with push-button which connects the HT via a relay, for a short time (say 2 minutes) when a button is pressed? It means add-on circuitry and a hole for a button - but if the cabinet is a bit ropey then you may not mind.