Okay, suppose I make a colorburst CW oscillator and shunt it with a 50
ohm resistor.
I'd put a random wire at the top of the resistor.

So from basic equations P = (EE)/R, with a power limit of 1.7 nanovolt
this gives a voltage limit of 0.6 microvolt.

I'm afraid I don't have a voltmeter or scope that goes that low.

The Eternal Squire

On Jan 25, 9:44 pm, "John" wrote:
wrote in oglegroups.com...

My question is this: so long as final output to the antenna is within
the requirement of part 15 unlicensed operation, is part 15 unlicensed
operation allowed within a band normally governed under part 97?
Part 15 operation would easily cover a 30 mile radius on 80M. http://www.access.gpo.gov/nara/cfr/w...7cfr15_06.html

Part 15.223 says in part...

"Subpart C_Intentional Radiators
Sec. 15.223 Operation in the band 1.705-10 MHz.

(a) The field strength of any emission within the band 1.705-10.0
MHz shall not exceed 100 microvolts/meter at a distance of 30 meters.
However, if the bandwidth of the emission is less than 10% of the center
frequency, the field strength shall not exceed 15 microvolts/meter or
(the bandwidth of the device in kHz) divided by (the center frequency of
the device in MHz) microvolts/meter at a distance of 30 meters,
whichever is the higher level."

For CW operation, your bandwidth is zero for all practical purposes. You
will therefore be allowed 15 uV/m at 30 meters.

From this I made a very crude estimate of your allowed transmitter output
power. Assuming your transmitter antenna is 100% efficient and radiates
hemispherically, your transmitter output power is allowed to be no more than
about 1.7 nanowatts (1.7e-9 watts). For ideal circumstances (0 dB receiver
antenna gain, 100% efficient receiver antenna), you would get less than 5 uV
at a receiver 400 meters away. I stress that this is for ideal
circumstances. If your transmitting antenna is less efficient, you can run
more power, but less of your power gets launched. How efficient is that
antenna, anyway? On the other hand, your antenna may have some directivity
which would further limit your power.

This is making my head hurt.

All that can really be said about this estimate is that, to be safe, you
should not have much more than about 2 nanowatts output power unless you
have the ability to measure the field strength according to regulations.

Good luck with your project.

73,
John