Bush DAC90A output transformer. - Page 2 - UK Vintage Radio Repair and Restoration Discussion Forum

Ed_Dinning · 22nd Sep 2009, 7:57 pm

Hi Gents, the transformer will run a lot cooler so no risk of damage/ discolouration on white cabinets. There is also a 6.3V heater tap so that pilot lamps operate. There are 2 heater taps for the 90 & 90a, also a tap at approx 200V for the HT.

If you examine the chassis of these sets you will find that some of them were already drilled where the dropper fits to take an autotansformer, which was fitted as standard on the AC 91 I believe.
There would be no space for a double wound transformer on this chassis; the autotransformer fits neatly and looks the part, possibly more attractive than a capacitive dropper.
So if the dropper fails and there is no replacement available, it will slot in without calculations.
It could also be used on sets with similar valve line-ups

22nd Sep 2009, 7:57 pm	#21
Ed_Dinning Dekatron Join Date: Jan 2004 Location: Newcastle upon Tyne, Tyne & Wear, UK. Posts: 8,195	Re: Bush DAC90A output transformer. Hi Gents, the transformer will run a lot cooler so no risk of damage/ discolouration on white cabinets. There is also a 6.3V heater tap so that pilot lamps operate. There are 2 heater taps for the 90 & 90a, also a tap at approx 200V for the HT. If you examine the chassis of these sets you will find that some of them were already drilled where the dropper fits to take an autotansformer, which was fitted as standard on the AC 91 I believe. There would be no space for a double wound transformer on this chassis; the autotransformer fits neatly and looks the part, possibly more attractive than a capacitive dropper. So if the dropper fails and there is no replacement available, it will slot in without calculations. It could also be used on sets with similar valve line-ups