If its any help, I have an HP 4284A precision LCR meter with a basic uncertainty of 0.05%. It has a little over 8000 frequency points, that are VERY poorly spaced in the range of 20 Hz to 1 MHz. (There is 20 Hz, and 20.01 Hz, but nothing between 750 kHz and 1 MHz). After I attempted to set the frequency to 137 kHz, the display indicating 136.986 kHz. So if you want some components measured at very close to 137 kHz, I have an instrument able to do it. You can either send them to me or come here if it's convenient.

I don't have any spectrum analyzer or VNA that will work at those frequencies though.

G8WRB

Dr David Kirkby Ph.D C.Eng MIET
Kirkby Microwave Ltd
Registered office: Stokes Hall Lodge, Burnham Rd, Althorne, CHELMSFORD, Essex, CM3 6DT, United Kingdom.
Registered in England and Wales as company number 08914892
https://www.kirkbymicrowave.co.uk/
Tel 01621-680100 / +44 1621-680100