[Heatercathodeshort]

Hello Colin,
Now you are almost ready to proceed with work on the frame timebase and signal circuits it might be as well to warn you that some capacitors in Ekco receivers appear to be into cross dressing. They look exactly like resistors but under their coloured frocks they are in fact low value capacitors.
They are dark brown in colour with coloured bands that read exactly as the resistor code. i.e Brown Black Red = 1000pf. They generally tend to go O/C after all these years but sometimes develop a very high resistance leak, enough to upset frame linearity. The big fat diode pictured is the frame interlace filter [D3]. Again it goes O/C giving very poor frame lock. These components were made by a company owned by Ekco named EGEN situated just down the road from their factory at Canvey Island Essex. Ekco timebases should be rock solid. It can be replaced by any small diode such as the 1N4001. Another very puzzling fault, poor contrast, odd contrast operation, contrast overload and brightness variations is often due to the video amplifiers anode load resistor [12k] going high resistance typically around 20K. Worth a check. Similar symptoms to the above are also caused by the .1uf wax capacitor INSIDE the tuner. Easy to replace once you know it's there. It decouples the AGC line and goes very leaky. The tuner bottom cover [if it's still there..] will need to be unclipped and the R.F. coil biscuits removed to gain access. I can post a pictorial explanation of this if you need it.
Can't think of anything else that will slip you up at the moment. If the AGC decoupling capacitors are leaky you may find it difficult to adjust the contrast. The AURORA output is clean and strong and the uncontrolled signal stages may overload and give a negative picture. Cheers, John.