WOW, I do not understand the distinction - there must be some harmonic suppression circuits that reduce the 2nd harmonic emissions from an amplifier (40 dBc if I recall), so whether that is done using a fixed tune output circuit, or whether that is achieved by the use of an external antenna tuner is a moot point. The bottom line is that somewhere in the path between the PA tubes (transistors, MOSFETs), there must be a path from the grid(, base, plate) to ground that will afford a transition to 50 ohms (and X - j0) solution that will yield greater than 5 watts on all bands (or in the case of the K3, 6 meters).
So use whatever tuner matching section between the amplifier and the antenna is a good and prudent challenge. The inductance at the highest frequency will be greater than 3 times the 'oscilloscope oscilloscope and probe - 73, Don W3FPR On 2/20/2012 11:34 PM, Hank Garretson wrote: > On Mon, Feb 20, 2012 at 8:18 PM, Ron D'Eau Claire<[email protected]> wrote: > > Note that "No Tune" means, simply, "Fixed Tuned", set for a 50 ohm >> non-reactive load on each band. If we don't have an antenna reasonably flat >> across the whole band we add an "Antenna Tuner" to the output which is >> simply moving the tuning we used to do on the xmtr output to an outboard >> box! >> > Not exactly. My "No Tune" ACOM 2000A will automatically handle up to 3:1 > SWR on all bands except 160 where the limit is 2:1. Sometimes output power > is reduced, and sometimes an external tuner is helpful. but for the ACOM at > least, "No Tune" does not mean "Fixed Tune." > > 73, > > Hank, W6SX > > Mammoth Lakes, California > > Elevation 8083 feet in John Muir's Range of Light > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:[email protected] > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
