View Single Post
Old 28th Apr 2017, 7:48 pm   #10
turretslug
Dekatron
 
turretslug's Avatar
 
Join Date: Nov 2011
Location: Surrey, UK.
Posts: 4,385
Default Re: GEC BRT402D Receiver.

Ken, there are no electrolytics in the set- as a (rather expensive!) professional receiver of its time, they were avoided as suspect components. Just as well really, as they would quickly have been broiled to extinction. If it's the 3x 2uF paper blocks under the chassis with 22k composition resistors strung between them that you mean, these are for the c. -100V AGC amplifier supply- only around 2mA is drawn from this rail but it does need to be a smooth 2mA. It uses 2 rather bulky metal rectifiers and these are unlikely to be as good as they were nearly 70 years ago... The HT smoothing capacitors are 4uF and 2uF paper blocks above chassis next to the mains transformer- as the off-load HT is only around 400V, you could get away with electrolytics here, but it goes without saying that 105 degree types would be wise!,

Colin
turretslug is offline