🚀 go-pugleaf

In article <1426@umd5>, cgs@umd5 (Chris Sylvain) writes:
> In article <1438@nicmad.UUCP> brown@nicmad.UUCP (Mr. Video) writes:
> >In article <4484@watmath.UUCP> mwtilden@watmath.UUCP (M.W. Tilden, Hardware) writes:
> >>Anybody know of any circuits or modules that can transmit NTSC black/white
> >>put real-time vision on a radio-controlled plane.  Any magazine referances 
> >>or books would be helpful.  Please respond via E-mail and I'll post a summary
> >Before anybody says anything else:  Any tv transmitter that can transmit for
> >at least 2 miles will require FCC approval.  In other words, forget it.  Not
> >only that, you probably couldn't get it to fit in the plane.
> >
> >Mr. Video
> 
> Not true! The FCC has allocated bands in which one does not need a license
> of any kind to use the frequencies with any kind of modulation desired.
> The only restriction is the field strength measured at a specified distance
> from the transmitting antenna. One may use any amount of RF power as long

No, no, no, no. The operation being contemplated by the original poster
does NOT fall under 47 CFR 15 anyway (part 15 of the FCC Rules and Regs).
Nevertheless, these would be the power maximums for "low power communications
devices":

    47CFR15.112(a) - 160 to 190 kHz - one watt input power 
    47CFR15.113(a) - 510 to 1600 kHz - 0.1 watt input power
    47CFR15.114(a) - cordless telephone - 50 mV/m at 3 meters at carrier F
    47CFR15.115    - device illegal to operate from 26.97 to 27.27 mHz
                     (operations cease Sept 18, 1983) as 
    47CFR15.116    - 26.99 to 27.26 - voice and data prohibited (A3,F3,A1)
                     10 mV/m at 3 meters at carrier F 
    47CFR15.117    - 49.82 to 49.90 - 10 mV/m at 3 meters at carrier F
                     Emissions not wider than 20 kHz
    47CFR15.119    - Home built device (5 or less)
                     Not marketed
                     49.82 to 49.90
                     (b) "the power input to the device at the batter
                          or power line terminals shall not exceed 100
                          milliwatts under any condition of modulation
    47CFR15.122    - (above 70 mHz) - transmission duration not greater
                     than one second and silent period of at least 
                     30 times the transmitting duration. 500 uV/m at 3 m

     Nevertheless, I would challenge anyone to make a radiofrequency power
amplifier with 1 kw RF output and sufficiently shield it to limit radiation
to 50 mV/m at 3 meters.  

     Generally speaking, the FCC frowns big-time on homebuilt devices which
have a DC input power to the final radiofrequency amplifier of 0.1 watts
or more. While this has not been set in stone as a rule, it is certainly
something which the local EIC (Engineer in Charge) could insist on if 
pushed.  Furthermore, there is this business of self-certification which
have been prosecuted.

     None of the part 15 frequencies would be suitable for television,
anyway.

David Anthony
DataSpan, Inc.