Am receiver frequency readout

[Nick]

I thought there was a Link on here somewhere to a Chinese (?) Counter and Display PCB which allowed the IF Offset to be entered. However, I'm damned if I can find it

These are very simple to do with a uP and normally limited to 40MHz as that's all CMOS handles - you still need the prescaler and the OP wants an analogue display.

What you need is, instead of driving an character LCD, for the uP to produce a PWM output proportional to the frequency range of interest - a simple RC integrator followed by a unity gain buffer & analogue meter would then be all that's needed.

The SAB6456T can divide by 64 or 256 and is designed to be driven directly from a local oscillator - 10mV sensitivity and accepts sine wave input - all the pulse shaping is done for you - the output of this could be fed directly into a uP which would then produce the adjusted PWM output. 2 chips only and a handful (maybe 10) other passive components, No CMOS divider, pots or 555 needed... you don't even need an xtal for the uP as its clock rate and stability is unimportant - you can use the internal oscillator so long as its fast enough to detect the edge trigger from the output of the prescaler.

EDIT: RATS! The SAB6456T seems to be discontinued - I loved this chip... However, there will be others out there that do the same...