[Lowfer] BCY

[Lyle Koehler]

As Dale points out, the CD4024 part is relatively low speed and may not work
if your crystal frequency is too high. With a 5 volt supply, the typical
maximum clock frequency is 5 MHz, but the guaranteed spec is much lower than
that.

I haven't had any problems with the 74HC4060 oscillator/divider circuit as
used in the "simple LowFER transmitter" at
http://www.computerpro.com/~lyle/lftx.htm. If the oscillator circuit is
located in a reasonably constant temperature environment, the drift
shouldn't be much of a problem. It's primarily the crystal itself that
determines the frequency stability, rather than the rest of the circuit. If
necessary, a PTC thermistor can be attached to the crystal to serve as a
combination heater and temperature controller, as described in my "all in
one" transmitter article at
http://www.computerpro.com/~lyle/all-in-one/all-in-1.htm This simple and
effective stabilization technique was "stolen" from the VHF and microwave
guys.

Lyle, K0LR