This is why the K4 (and a small number of other transceivers) include "active predistortion" capability in hardware. It adapts the drive power to the response curve of the PA stage. The K4 also has an TX sample input to include an external amplifier in the correction loop. (The KPA1500 has a TX sample output for this purpose.)
We expect to post numbers significantly better than the industry's typical 3rd-order intermod performance at 100 W, which stands at about -30 dBc (ARRL method). 73, Wayne N6KR > On Nov 4, 2019, at 7:48 AM, Bill Johnson <k9...@live.com> wrote: > > Thank you, Bob. Rob, clarified to me. Seems most transmitters are in the > same boat using solid state transmitters/amplifiers, vs. tubes. > > 73, > Bill > K9YEQ > > > -----Original Message----- > From: elecraft-boun...@mailman.qth.net <elecraft-boun...@mailman.qth.net> On > Behalf Of Bob McGraw K4TAX > Sent: Sunday, November 3, 2019 7:25 PM > To: Elecraft Reflector <elecraft@mailman.qth.net> > Subject: Re: [Elecraft] [Elecraft-K3] K3S to be discontinued > > I suppose I am the "Bob" you refer to. The section in Rob's article on > Odd-Order Intermodulation he clearly explains "worse". > > Our receivers have gotten much better over the years but unfortunately our > transmitters and amplifiers have gotten worse. To quantify, the ARRL > published a compendium of distortion products of linear amplifiers in 1997. > The third order distortion was in the 40 and 50 dB PEP range. In 2019 an ARRL > review of solid state legal limit amplifiers reported the third order > distortion was only down 30 dB. This is a 10 to 20 dB degradation from 1997 > to 2019. I'd call this "worse". > > 73 > > Bob, K4TAX > > On 11/3/2019 6:56 PM, Bill K9YEQ wrote: >> >> “worse” seems a bit much when looking at the actual levels. Bob, did >> you mean something else? I know this is semantics…. >> >> 73, >> >> Bill >> >> K9YEQ ______________________________________________________________ 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 Message delivered to arch...@mail-archive.com
