[sdiy] A Frequency Standard for Poor People?

[Czech Martin]

Depends very much on what you are doing.

If you want to do absolute measurment, a good counter is a must.
If you use an old Intersil CMOS IC, you can build one
for 50 EUR on a weekend. Did that 20 years ago.
The accuracy depends on the on chip quartz oscillator,
but much more on the signal! Low frequency sine waves
can make the triggering very uncertain, thus the period reading
can be very uncertain. I.e. most analog wide band oscillators
have terrible phase noise! 

There are reciprocal counters available as kit, they do the
reciproce of the period for you, so you can measure audio
frequency signals without 10s gate time or using the pocket
calculator.

Sometimes absolute values are needed, I need now absolute frequencies
for T/S parameters.

In most musical applications only relative accuracy is interesting.
In those cases you can live with a cheap quartz oscillator and a :2
divider chain, giving a lot of octaves. The tuning to this by beating
is more accurate then the counter reading, if real world noise
is considered.

m.c.