[Niechcial,Steve]

I got so far with working on the second receiver/decoder chassis I have. Having done a blanket replacement of the usual suspects, plus several transistors with a rotted through leg, I finished up with a good monochrome picture and sound, with just a trace of the red colour bar. At this point I ran into a totally exasperating problem. The first chroma amp stage was showing very little gain, and the gain didn't change with the saturation or preset saturation controls. It's a very simple one transistor circuit which sits on a board of its own under the IF strip. Several of the resistors in the base bias circuit were well out and so replaced. Transistor (BC108) checked OK but replaced .I checked for signal at the base, DC voltages (ok) and for cracks in the board etc. The Collector load is just an air cored coil shunted by a 1K damping resistor. Presumably the coil is designed to resonate around 4.43 MHz. I'm wondering if the prolonged exposure to damp has damaged the response curve. Feels unlikely as it's wound with DCC rather than enamel wire. I can't think what else it could possibly be though. Anyway, I've had enough for the moment. All suggestions welcome.
I have re-assembled the set with the original chassis and the picture is excellent. I attach photos. The horizontal lines are entirely camera artefacts. That funny colour smearing on both b/w and colour pictures was entirely due to the preset contrast being set too high. I was able to replicate it on chassis number 2. Once set up as per the manual the streaking vanished.