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View Full Version : FCC amends rules to remove some restrictions on spread-spectrum transmissions


NQ6U
03-04-2011, 12:18 PM
The FCC has amended Part 97 to "eliminate the requirement that an amateur station use automatic
power control (APC) to reduce transmitter power when the station transmits a SS emission" but
"reduce the maximum allowed transmitter output power for an amateur station transmitting a SS emission."

Full text in a PDF here:

http://hraunfoss.fcc.gov/edocs_public/attachmatch/FCC-11-22A1.pdf
ab1ga
03-04-2011, 05:09 PM
A good thing overall, I think. This decision will make it easier to experiment by removing the APC requirement, while at the same time reducing the potential of interference to other stations. It will be important for SS users to make sure their activities don't raise the noise floor for other weak-signal enthusiasts by keeping the edges of their emissions away from those slices of spectrum. Wishful thinking, I know.
NQ6U
03-04-2011, 05:16 PM
Experimenters will have to reduce their power levels so that might be a plus when it comes to other weak-signal work. And as far as I know, SS transmissions in the U.S. are still required to be made only at 220 MHz and above. Is there a lot of weak-signal work done on those frequencies?
ab1ga
03-04-2011, 05:27 PM
Experimenters will have to reduce their power levels so that might be a plus when it comes to other weak-signal work. And as far as I know, SS transmissions in the U.S. are still required to be made only at 220 MHz and above. Is there a lot of weak-signal work done on those frequencies?

Yes, there is. In fact, as you go higher in frequency, natural background noise goes down, so any man-made sources will raise the noise floor. There isn't a lot of activity, at least not compared to repeaters, etc., but the spectrum slice is small, 100kHz wide or so, near the low end of the band. It's where the DX windows, EME, etc. folk hang out.

73,