On Sat, 27 May 2017 12:55:02 -0400, wrote:

Look for something that has a built in prescaler. Something like
this:
http://www.ebay.com/itm/Blue-RF-Signal-Frequency-Counter-Cymometer-Tester-0-1-60MHz-20MHz-2400MHZ/172396798620
The basic counter goes from 100KHz to 60MHz. The other ranges use a
prescaler to divide down the input frequency so that it ends up at
less than 60MHz and can be counted.

Or, maybe one of these variations:
http://www.ebay.com/itm/Digital-6LED-1MHz-1000MHz-1GHz-RF-Signal-Frequency-Counter-Cymometer-Tester-G-/222009256193
http://www.ebay.com/itm/1MHz-1200MHz-RF-Frequency-Counter-Tester-Digital-LED-METER-Cymometer-f-Ham-Radio-/331915125484
http://www.ebay.com/itm/2016-0-91-OLED-RF-1Hz-2-4GHz-Frequency-Counter-Meter-Cymometer-Tester-/172692754650

You can also use a mixer to take a higher frequency signal, and mix it
down to something lower that the counter can handle. I have some HP
microwave counters that work like that.

--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558