old clocks

To me, those are 2 differnet things -- a radio-controlled clock is one that receives a standard time signal (which is almost certainly based on an atomic clock). An atomic clock implies to me that the beam stnadard is 'local' - -that is that you are running it yourself. Making a time signal receiver to run a slave clock shouldn't be too hard. You don't need to decode the time data in the signal (I asusme you are not going to try to se the hands automatically, since that would require significant modifications to the slave clock so the control system can determine where the hands are, or at least to be able to detect when they're at 12 o'clock) so you can have a known reference point). What you nwed to be able to do is recognise the 'minute marker' (which in the xase of MSF is a sequence of long and short pulses sent one per second before the minute time whichcann occur nowhere else in the signal (since the time data, also encoded by long nad short pulses is sent in BCD). One you have the minute marker decoded, you essentially have one pulse per minute. You then need to turn that into suitable pulses for your slave clock. The things you need ot knw are the voltage/current required, the pulse length required and whether you have to invert the pulse on every other minute (see my description of the system we had at school). I beelvie you can now buy receiver modules for the standard time signals that output a nice logic-level signal. This takes all the fun out of it -- I had to build and align my own receiver when I did it. It's not that hard to do, the frequencies involved are pretty low which helps a lot. -tony