Philips-Fluke PM6665 Frequency Counter with Oven Controlled Crystal Oscillator

Wed, 23 Dec 2015 00:00:00 +0000

Upgrading a Philips-Fluke PM6665 Frequency Counter with an Oven Controlled Crystal Oscillator - Up and Running!

I needed a frequency counter for my little lab at home. Naturally, I wanted an HP Agilent 53132A or similar, but it’s way too expensive for my modest use. So I browsed around eBay and found an old Philips-Fluke PM6665 frequency counter with the optional 1.3GHz add-on board. With a 10 second gate time, I can get down to 0.1 Hz at 10 MHz, so that’s more than I need. It didn’t have the option of a better crystal, unfortunately. When I tested the PM6665 against my Trimble 10 MHz GPSDO reference, the unit was off by 200.1 Hz. Without a calibration sticker on the instrument, I’d say that’s pretty good for a device manufactured in the late 80s. I tried to trim it, but it uses an adjustable capacitor, and you only needed to look at it for it to change settings.

Counter on Jackenhack

Philips-Fluke PM6665 Frequency Counter with Oven Controlled Crystal Oscillator

Upgrading a Philips-Fluke PM6665 Frequency Counter with an Oven Controlled Crystal Oscillator - Up and Running!