50MHz Frequency Meter Kit

[Terry]

There was a lot of discussion about frequency measurements in an earlier thread so this Elektor article might be of interest.

Ignore Elektor's £16 price tag (they're out of stock anyway) as it is available direct from Banggood for only £7.13!

If you want to go higher, there's a ready built 500MHz meter for £11.10 - but you'll need to build a case for it and for £15.76, complete with case, you can get all the way up to 2.4GHz!

I still find it hard to believe these low prices. The multimeter prices in the other thread were low too, but there are probably many more times the numbers sold to help keep the prices down.

[Nick]

The cheap price for these is basically because almost everything is done by a single PIC microcontroller, typically a 16F628A.

The 500MHz version is essentially the same as the 50MHz one with the addition of a prescaler.

They have been around for maybe 10 years or more, so are tried and tested. Main problem is with the reference frequency which is the PIC's clock - this is a cheap crystal with a ceramic trimmer, so don't expect huge accuracy or temperature stability...

It's excellent value for what it is.

[Refugee]

Those can be upgraded with a more expensive crystal unit for purists.

[BusyBee]

I have just bought a meter which looks like one of these. I have not tested it fully yet, but seems Ok for the price.

Tracy

[Mark Hennessy]

In fairness, given that these are only 5 digit counters, I'd expect that even a fairly pedestrian crystal would be more than adequate...