My understanding of current FCC regs is
* the mean power of any spurious emission from HF transmitters or external
RF power amplifiers installed after January 1, 2003, must be at least 43 dB
below the mean power of the fundamental emission.
* the mean power of any spurious emission from HF transmitters or external
RF power amplifiers installed on or before January 1, 2003, must not exceed 50
mW and must be at least 40 dB below the mean power of the fundamental emission.
If the mean power output of such as transmitter is less than 5 W, the
attenuation must be at least 30 dB.
Still exempt from the provisions of §97.307(d) are transmitters built before
April 15, 1977, or those first marketed before January 1, 1978.
I don't believe a pi net of Qo 12-15 can achieve -43 dBc suppression of the
second harmonic. The numbers I'm coming up with are an order of magnitude
worse. So, shouldn't any new amplifier design include a pi-L tank, or external
lowpass or bandpass filtering?
73,
Jim, KR1S
http://kr1s.kearman.com/
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