Tracor 900A VLF/LF Rx experience

[wd5jfr]

Just picked one up at a hamfest and never have seen or heard of one.  Seems to be in pretty good physical condition so I'll have to try it out once I get my bench cleaned up and organized. It'll  track 100 KHz or 1 MHz standard drift compared to whatever VLF/LF stations you can receive.  Most of my stuff has 5 or 10 MHz standards, so I wonder if anyone has tried with 5 or 10.
Thanks
Hank

here's link to manual https://www.glkinst.com/test-equipment/manuals/Tracor900A.pdf

[5065AGuru]

I've worked on a few of these and they work very well. unfortunately since the modulation change it wont work on WWVB! 

The main problem I found was bad switches! They need to work or you can't select the correct frequency!

Cheers,
Corby