Technical Topics > Part 15 AM and FM Station Operation

Radio Survivor - Social Distancing Sparks Interest in Part 15 Unlicensed Broadca

(1/2) > >>

ThaDood:
Here's the full, unchopped, title:  Radio Survivor - Social Distancing Sparks Interest in Part 15 Unlicensed Broadcasting, but Caveat Emptor.  Here's the link,      http://www.radiosurvivor.com/2020/09/21/social-distancing-sparks-interest-in-part-15-unlicensed-broadcasting-but-caveat-emptor/

On Part #15 FM, there no actual RF power out limit, but just that limiting FS limit of 250uV measured at 3 Meters away. I do remember that someone in the 1990's Panaxis EBN (Experimental Broadcaster's Newsletter) calculating with the possible RF OUT would be to a 1/4-Wave GND Plane Antenna, and it was something like 600pW - 800pW. That's picowatts, 10 to the -12! That small!!! 

Kingbear Radio:
I've been hearing about this, seeing the videos in my feeds with churches and others using part 15, and thought it's good that radio is being used as a cheap and simple way to serve an audience.

Well, if that's true, picowatts, a little power goes a long way.

ThaDood:
Well, there's still AM Carrier-Current Coupling, (Loading to the power lines.), that's still totally permissible, like some schools and colleges still do. However, lack of gear, with Radio Systems and LPB, Inc., gone bye-bye, and the idea of coupling to the power lines, seems to set most folks away from that idea. You can Neutral Inject, like my AM610 is. If a mega church parking lot is big enough, where they have a dozen light poles lighting that, you can couple to those power lines and easily cover that whole lot with less than a watt carrier. Not a new idea either, since many Drive-In Movie Theatres have done that for decades, after they trashed their pull-aside window speakers. (Remember them?) The smart owners just coupled into the old speaker wiring. Can still be done.

Kingbear Radio:
Carrier-Current sounds like a good idea too. I can see at a school how they would use special wiring, to reach all of the buildings through wires branching out to them; more planning would be needed in that case.

For something simple, like at a church through the light poles, could the transmitter just broadcast through a an AC plug in the wall and transmit Carrier-Current that way? That would be even easier, with no antennas to set up!

I think churchgoers are more likely to accept AM for voice modulation to hear their pastor's voice.

chanito:
Splattering on aviation frequencies is not to be taken lightly. "I wanted to play Pixies and Concrete Blonde but some plane crashed..".

Navigation

[0] Message Index

[#] Next page