Larry Jaques wrote:

Winston wrote:

Also beware that HF digital calipers tend to be very
susceptible to RFI. If I put my cheapo plastic
calipers next to a fluorescent fixture, they go all
wonky until placed well away.

Prolly the plastic conducting sunspot activity.



Sigh. 'Prolly' the comment of a know it all.

The RFI is caused by the circuitry rectifying the RF, and injecting
noise into the analog portions on the equipment. At RF levels high
enough to affect the digital portion can destroy the equipment. A
fluorescent light generates noise well past 4 GHz. I used to use the
one on my bench to test C-band LNAs, LNBs & LNCs before I got a
calibrated C-band signal generator. Simply holding one end of a signal
diode and connecting a voltmeter between the other end and earth (Safety
ground) will show you how much energy is wasted as RF in fluorescent
lights. I made a test fixture to sort thousands of small signal diodes
by output voltage about 40 years ago. The ones with the highest output
gave the highest sensitivity as a detector. I tossed the worst, and used
the rest for diode logic circuits.


--
You can't have a sense of humor, if you have no sense.