Hi all.
Thank you for the very kind comments, although most of them belong to the kind folks who helped me sort the bloddy thing out.
For anyone interested in the circuit diagram (or something similar at least), here is a link to a work-in-progress scan for the original 21KX100A. I'm afraid I don't have a diagram specifically for the 21KX102A although I have got different circuits for the 21KX105A and other odds-and-ends enough to work out the general circuit. (It's a case of having to work out which circuit fits any particular section.)
http://www.oldtechnology.net/misc/21...n_Progress.png
Interesting things to look out for are the unusual configuration of the anode and cathode of B302P, the strange audio circuit using a pair of high-impedance speakers in series, the direct / flywheel sync switch for the line oscillator / phase discriminator circuit and the flywheel-a-like frame circuit (which I never quite understood). If anyone would like any more info or diagrams then I'll happily post them.
Maarten, I'll find out the details when I get back to Solihull and let you know. I think there are a few of these sets kicking around in the UK.
One odd thing about this set is that although it has a combined VHF / UHF tuner similar to that used in many continental Philips sets, there is no way of knowing what channel you are on when switched to UHF. The 21KX100A had a display window indicating the channel number but had no motorised control buttons. The place where the window might otherwise have been on the '102A is taken up by a small button to choose between UHF and VHF - The same function button on the '100A was with the On-Off / Speech-Music / Colour Off switches at the bottom of the set.
Graham - Re a remote-control option, the set does indeed have a B9A plug on the back for adjusting the controls but I've never seen (or even heard mention of) a remote control for the set. It seems a little bit of a strange thing where you could change the volume, brightness, contrast and colour but there was no facility to switch the set on or off or change the channel.
Neil - The underside of the set was incredibly intimidating when first viewed but it all kind-of "sinks in" after a bit and it doesn't seem as bad. The biggest problem with it is trying to access the components - You need to lay on the floor on your front - and then you end up with a cricked neck. I've had to ask my neighbour to help me lift the set onto a very sturdy table for the last couple of fixing sessions.
Just as an aside, I think (hope) this set will be impressively reliable as all the resistors I measured seemed to be very high stability and had not changed by hardly as much as an ohm. The caps are mostly all mustards and I have yet to find a faulty one. The only things I've had to change really (apart from those two low-value caps in the line oscillator) have been the occasional valve, the VDR which had physically broken and the lopty. (I suspect I've contradicted myself somewhere there - but the point is that apart from those components mentioned there has hardly been a single component changed in the set's 54 year life.)*
Thanks again all.
Kind regards.
From Mike.
*Actually, I just spotted a few electrolytics and a couple of black pitch caps in the photo of the chassis that I changed along the way.