Thanks, Scott! I'm going to change the way I do things so that ATU is always in, and the Palstar HF-Auto switches to AUTO mode rather than Manual to keep the match seen by the KPA below 1.2:1
- pjd -----Original Message----- From: K9MA <k...@sdellington.us> Sent: Tuesday, March 12, 2019 1:53 PM To: Peter Dougherty <li...@w2irt.net> Cc: Reflector Elecraft <elecraft@mailman.qth.net> Subject: Re: [Elecraft] KPA-1500 tuner questions Just a general comment on the KPA1500: My experience with it shows that the SWR has to be below 1.2:1 at the amplifier output (ATU input) to run reliably at full power. If the SWR is higher than that, the amp will often fault due to excessive current or drive power before reaching 1500 W. (And may splatter on SSB.) Elecraft recently updated the ATU firmware to consistently find a better match, and it really helps. 73, Scott K9MA ---------- Scott Ellington --- via iPad > On Mar 11, 2019, at 8:49 PM, Peter Dougherty <li...@w2irt.net> wrote: > > I have a couple of questions about the KPA1500's internal tuner. > > For the most part, I leave the tuner inline. Except for two sub-bands > (SSB on both 40 and 80m) I am well below 2:1, and maybe 2.5:1 at the > top end of 160m. The KPA does a good job throughout. > > The problems/questions arise when I need to transition between the > KPA's internal tuner on the bottom ends of both 40 and 80, and the > external Palstar HF-Auto tuner, which I need to wrangle very high SWRs > on the phone portions of those bands. Obviously I don't want both > automatic tuners inline at the same time. The situation is most acute on 40. > > The HF-Auto (external automatic tuner) is bypassed everywhere except > the range of 3650 to 4000, and 7100 to 7300. I would like to > automatically have the KPA1500's tuner go into bypass at the above > ranges, just as the Palstar auto-tuner bypasses outside of those > ranges. Is this somehow possible, or must I manually switch the tuner > in and out when I cross the appropriate thresholds? > > Second question, and I think this relates to the whole "bins" thing, > which I don't understand, relates to having different tuning solutions > on the same band segment. This could be handy for me on 80m. Unlike on > 40, for 80 I have an inverted vee, and it's easy for me to drop the > ends and change the length of the antenna, so that instead of being > resonant at 3550 I could make it 3700. I did this for the ARRL-SSB > contest and it worked pretty well. Is it possible to have two > different sets of memorized tuning solutions in the KPA-1500, in the > event I have the vee set for CW (normal) or SSB (for phone contests only)? > > > --------------------------------------------- > 73 and Good DX > Peter, W2IRT > > > > President, North Jersey DX Association > > DXCC Card Checker > Letter O Manager, ARRL Incoming 2nd District QSL bureau > > > > ______________________________________________________________ > 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 ______________________________________________________________ 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
