[1000mp] ARRL Lab transmit IMD test-result reporting

[lhlousek]

Hi Tom,

Can't argue that cleaner signals would be better and that the two tone test is probably a good one for comparing the
relative performance of rigs but applying those results to calculate actual IMD caused interference seems somewhat
tricky to me. The worst possible situation for generating IMD products is two equal pure tones that sum up to the rated
power of the transmitter but actual SSB transmission consist of an envelope of frequencies over the transmitted
bandwidth with no pair of frequency getting close to the levels used in the test.  Since intermod products vary with
higher powers of the applied signals would not the IMD products be much lower (more than proportionately lower) with
respect to PEP (or average power) in this case?

Your point about an ops responsibility to not cause QRM is well taken.  There is a lot of QRP and QRPp  going on these
days (I worked 500mW LZ2RS while I was at 2W on three separate occasions last week)  so it's getting a lot easier to QRM
somebody with out of band emissions from a QRO station.

Lou W7DZN.