> At 1 mW or less on its operating frequency, this is unlikely to cause > any problems. The 2nd harmonic and higher order even harmonics are over > 30 dB down from that, and the odd harmonics are 7-10 dB down. It > certainly shouldn't cause any issues at VHF.
> That said, you can always add a simple in-line LPF to roll off the > harmonics the additional amount desired. > 73, Eric You may be right, Eric. FCC Part 97.307(e) states: "The mean power of any spurious emission from a station transmitter or external RF power amplifier transmitting on a frequency between 30-225 MHz must be at least 60 dB below the mean power of the fundamental. For a transmitter having a mean power of 25 W or less, the mean power of any spurious emission supplied to the antenna transmission line must not exceed 25 uW and must be at least 40 dB below the mean power of the fundamental emission, but need not be reduced below the power of 10 uW. A transmitter built before April 15, 1977, or first marketed before January 1, 1978, is exempt from this requirement. " If one is operating with the Fundamental at 1mW, then the spurii only need to be down a bit over 20 dB to be below 10uW. This would imply from Eric's figures above, that one might need an additional 10-13 dB of attenuation at the 3rd harmonic to be compliant. Bruce, N1RX ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
