Valve Radio Restoration

	Bush DAC90A The radio as it arrived. A little marked and scratched but nothing that couldn't be polished out. This set works directly off 230 volt mains so make sure the chassis is not connected to live! Both live and neutral go through the on/off switch on the back of the volume control. Neutral is not connected directly to chassis but goes via a 75 Ohm resistor which has two series-connected bulbs in parallel with it. These bulbs, rated at 3.5 volts, 150mA, illuminate the panel.
	Rear view with cover removed. The main fault was "hum on audio" even with the volume control set at zero. My valve tester soon showed the culprit to be the UL41 output valve which had a cathode-heater short when hot. A replacement from Wilson Valves cured that symptom. The other fault was that the waveband change knob rotated through 360 degrees. It shouldn't! Someone had turned it with too much force and had sheared off the central bronze wiper which normally is located between two small pegs. I used tin plated steel to make another and soldered it in place.
	AVO C.T.160 valve tester This is my own. The serial number is AVO2386 and it's a little beauty. I've had the AVO Valve Data Manual for the last 20 years - I inherited it from my Father. So, when I heard that Veta at Colomor (Electronics) Ltd. had the actual tester for sale, I posted my cheque for £150 immediately. You can contact Veta at: giacomelli@colomor.demon.co.uk

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