[Milsurplus] LM21 Freq Meter - In use until?

[Greg Werstiuk]

I'm finally getting around to tidying up a variety of items I've collected
over the last 5 years or so.

Considering the significant improvement in frequency standards and frequency
counter time bases since WWII, I was quite surprised to find the Navy Cal
sticker on my stock AC Powered LM21 showed last/next cal dates of 1968.

Anybody know how long the government used the BC221 and LM21 frequeny
meters?


- Greg