It obviously wouldn't be of use for Part 15, but I still wonder what exactly is it?
DeVale Inc Systems Range Analyzer vintage Radio HAM AM FM CB electronics kit https://www.ebay.com/itm/157736215168
Looks like something for CB and HAM radios and even covers FM or AM frequencies according to the description but not sure about that, that measures the power and estimates the distance it could be received with a receiver at certain sensitivities.
Looks like something useful to us if it actually does AM and FM. I don't know if it actually measures a signal or how if by direct input or off the air. May just calculate based on input info. Just a calculator of some kind.
@mark Well, I don't know, but just from looking a the pictures, the adjustments knobs entail the receiver sensitivity (.01-12.0 microvolts), transmitter power (1-640 watts), tower height (15-1,000 feet), antenna gain or cable loss db (40, 160, or 450), and finally the meter indicating "Range-Miles".
That's why I said it probably wouldn't be much use for part 15, but I'm still curious about it.