Ron - Well, a little research can be a useful thing!
The FCC Part 97 rule is now 97.307. General requirement is 43 dB below "mean output power".
The last sentence is not really clear, but implies that this requirement does NOT apply to transmitters first marketed before Jan 1, 1978.
(d) For transmitters installed after January 1, 2003, the mean power of any spurious emission from a station transmitter or external RF amplifier transmitting on a frequency below 30 MHz must be at least 43 dB below the mean power of the fundamental emission. For transmissions installed on or before January 1, 2003, the mean power of any spurious emission from a station transmitter or external RF power amplifier transmitting on a frequency below 30 MHz must not exceed 50 mW and must be at least 40 dB below the mean power of the fundamental emission. For a transmitter of mean power less than 5W installed on or before January 1, 2003, the attenuation must be at least 30 dB . A transmitter built before April 15, 1977, or first marketed before January 1, 1978, is exempt from this requirement.
73, Garey - K4OAH Glen Allen, VA Drake 2-B, 4-B, C-Line & TR-4/C Service Supplement CDs <www.k4oah.com> Ron wrote:
I've often wondered why the TR series (with 3 finals) is only allowed 10 more milliamps of final plate current than the twins (with 2 tubes). That being 350 vs 340. Is it that multiple tubes in parallel are by their nature more prone to distortion and therefore harmonics? Ideas? If you are unaware, see this link. http://wb4hfn.com/DRAKE/DrakeArticles/TransmittingTuningAlt.htm 73, Ron WD8SBB
_______________________________________________ Drakelist mailing list [email protected] http://mailman.zerobeat.net/mailman/listinfo/drakelist
