OK, so I prototyped a circuit on breadboard to sync an xtal osc to 198 kc radio 4.
Performance is well rubbish, the o/p wanders by 10 to 15 hz at the loop filter rate.
The carrier is received by a simple trf receiver mounted remotely, this goes to a cmos gate where its squared then divided down to 2 kc, a 10mc xtal is also divided down to 2kc, the pair of 2kc signals go into a 4046 pll, the type 2 phase comparator goes into a 0.01 hz lpf which then biases a 500pf varicap diode in one leg of the xtal, there is a trim cap to get the o/p smack on 10mc with the control volts in the centre of the 5v rail.
But the o/p wanders around by 10hz or more, I think the mod on the carrier is making the pll go up and down.
In an attempt to remove the modulation I replaced the gate that squares the 200mv from the receiver with a ne567 pll tone decoder, a tranny on pin 5 takes off the synthsised signal which is a exact copy of the incoming signal, only a 0.1 hz loop filter is placed in the vco loop which I thought would remove pretty much all the mod, but it doesnt the system still wanders like its been on beer.
Is there such thing as a 198kc crystal filter?, I think it will take something like this to remove the am sidebands and phase mod from the carrier, maybe I could use a pll to multiply the carrier by 18 which gets close to 3.579 mcs uk colourburst frequency and use a ladder of these.