"Kim W5TIT" wrote

Hmmm, wouldn't Part 5 of Title 47 be the governing body for this? And, in
Part 5, there is the following:

PART 5--EXPERIMENTAL RADIO SERVICE (OTHER THAN BROADCAST)--Table of Contents
Subpart B--Applications and Licenses
Sec. 5.77 Change in equipment and emission characteristics.
(a) A change may be made in a licensed transmitter without specific
authorization from the Commission provided that the change does not
result in operations inconsistent with any term of the outstanding
authorization for the station involved.

Along with the above, this section goes on to define certain emission
standards, etc. I was just now trying to find the spec on emission
standards (rules?) as they apply to bandwidth. Correct me if I'm wrong--the
topic and rules of experimentation are way outta my league...no pun
intended. Would the above pertain to experimentation in the amateur bands?

Part 5 licenses are not "hobbiest" licenses, so the above does not
apply. These licenses are issued to manufacturers, inventors,
researchers, and students to experiment with new radio technologies,
new equipment designs, characteristics of radio wave propagation, or
new service concepts related to the use of the radio spectrum. Special
call signs (which look like amateur calls) are from the block K(or
W)x2Xyy. For example, KA2XYZ or WB2XYZ. The "call area" numeral is
always "2" and the letter following the 2 is always "X". My company
has 4 of these licenses related to 4 different products in
development. Rules regarding their use are very strict.

73, de Hans, K0HB