In case some of you did not know:
15.219 Operation in the band 510-1705 kHz.
I find the section pertaining to the out of band measurements interesting because of the two techniques provided for making such a measurement since they provide different results.
For example, my latest adventure into building a vacuum tube transmitter presented the opportunity to make this measurement. I have an oscilloscope which does a FFT analysis of the signal. Since my transmitter has a binding post connection for the antenna following the rule means attaching the scope probe to this terminal which is how I interpret "at the intentional radiator's antenna output terminal". Doing so presents the transmitter with a 12 pF capacitive load which requires retuning the transmitter. Under these conditions the harmonics and out of band signals are down 34 dBc.
The measurement done by measuring the radiated emissions which does not require retuning shows the out of band emissions are down 42 dBc.
In this case it is moot which method is used since both give results greatly better than required but I find it interesting that for the case of direct attachment to the antenna terminal the technique alters the loading on the transmitter and does not give a true reading for the actual radiated signal without such loading. I wonder why they wrote this this way.
Neil
Just so you know. The FCC has been doing research on the use of multiple transmitters for Part 15. That could be a good thing or a bad thing.