There are cheaper calibration standards. I bought one that was a TCXO 10,000,000ok thanks.
So I need a rubidium clock to hook up and say the same?
The seller isn’t able to respond. Review the listing again to see if it answers your question.here is a service and user manual on disk for your unit. cheap enough for the 2.
https://www.ebay.com/itm/FLUKE-1920A-FREQUENCY-COUNTER-OPERATING-SERVICE-MANUAL-/391826016937