UK Vintage Radio Repair and Restoration Discussion Forum - View Single Post - Roberts R200- Distorted Output

JoshWard · 21st Aug 2013, 1:56 pm

The distortion is present regardless of volume. I keep thinking it is a transistor fault but I have replaced the driver and output transistors with no change. It must be a bias fault but I can't seem to find it.

It works fine with the diode/transistor removed or with a silicon diode fitted, but as soon as I fit anything germanium I just can't get enough bias current.

Josh.

21st Aug 2013, 1:56 pm	#11
JoshWard Octode Join Date: Dec 2005 Location: Near Stowmarket, Suffolk, UK. Posts: 1,962	Re: Roberts R200- Distorted Output The distortion is present regardless of volume. I keep thinking it is a transistor fault but I have replaced the driver and output transistors with no change. It must be a bias fault but I can't seem to find it. It works fine with the diode/transistor removed or with a silicon diode fitted, but as soon as I fit anything germanium I just can't get enough bias current. Josh.