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

adibrook · 29th Jun 2006, 10:14 am

I'v managed to get a service sheet for my marconi radio.

I'v kind of poked about in a few places. The main 8uf smoother cap reformed, but the 4nd HT smoothing cap is very leaky. So now i think it's time to change some caps.

However...i'm pretty puzzled by the PSU. I'v looked at the schematic, and from that i could make out that the psu looks like this.

http://img.photobucket.com/albums/v4...ok/qmrkpsu.gif

This is really strange. I dont understand why there is a choke between shassis earth and the center tap on the transformer.

Before starting to take the radio appart and replacing caps, i would like to at least understand abit how it works. Can anyone explain the psu?

29th Jun 2006, 10:14 am	#1
adibrook Retired Dormant Member Join Date: Dec 2004 Location: Weymouth, Dorset, UK. Posts: 377	marconi 264 caps and PSU I'v managed to get a service sheet for my marconi radio. I'v kind of poked about in a few places. The main 8uf smoother cap reformed, but the 4nd HT smoothing cap is very leaky. So now i think it's time to change some caps. However...i'm pretty puzzled by the PSU. I'v looked at the schematic, and from that i could make out that the psu looks like this. http://img.photobucket.com/albums/v4...ok/qmrkpsu.gif This is really strange. I dont understand why there is a choke between shassis earth and the center tap on the transformer. Before starting to take the radio appart and replacing caps, i would like to at least understand abit how it works. Can anyone explain the psu?