Nigel Goodwin said:
The CMOS 4046 is probably the simplest and easiest PLL to use, building one from discrete devices is likely to be a LOT more complicated.
Not sure I really agree with that ... I suppose it depends on how wide a 'lock range' you want and wierd stuff like that but I have built a variant of
The Poor Man's Caesium Clock, using an XOR detector and bandgap-tuned crystal oscillator, nice and simple and works OK (after some tweaking of monostables in the TV line seperator ??).