I have a HY-Gain VB-66DX and 1.4 is the normal case basically across the whole band. I must be messing up somewhere, even the KPA1500 likes it. I have never run it over 1200 Watts on 6 meters and never requires over 30 watts drive to obtain 1200 out. I have three feet of 213U from amp to Palstar HF-AUTO (Bypass Mode), 70ft. of 9913 from the Palstar to a DX-Engineering 8 position Antenna switch, to my lightening protection and the final trip of 40ft of 213U to the antenna. The antenna is actually 10ft. above my HY-GAIN TH11 which also does not require a tuner. The Palstar is my antenna switch essentially but I do need it on my HY-GAIN HY-TOWER only on 160 and 80 meters when needed.
That's the end of my good luck story. LOL Ed..AB4IQ -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Bob McGraw K4TAX Sent: Tuesday, June 2, 2020 10:27 AM To: Mark Goldberg <[email protected]> Cc: Elecraft Mailing List <[email protected]> Subject: Re: [Elecraft] NOT the feedline As a rule, if one needs a tuner to get a good match on 6M, I'd say they need to look carefully at their antenna system. My 6M yagi shows less than 1.5:1 over the lower 2 MHz of the band, 50.0 - 52.0 MHz. The lowest SWR occurs at 50.2 with a Z value of 42 ohms and an X value of 0.0. Of course higher gain antennas typically have a bit less bandwidth, but still, the lower 1 MHz should be totally usable without a tuner. Besides, tuners only make the transmitter happy and the added feed line loss due to SWR still remains. 73 Bob, K4TAX On 6/2/2020 1:09 AM, Mark Goldberg wrote: > I want to mention that my LDG AT-600Pro has a minimum capacitance that > is too high for a good match to my antenna on 6 meters. Certainly > seems like removing the Ten Tec tuner would be a good thing to try. > Can you open the Ten Tec tuner and use an IR thermometer to monitor > the components? I don't know anything about it's construction. You > could see them heating up. > > Just running medium power of maybe 500W would slow things down and let > you see the SWR increasing before the amp trips. That would confirm > that something is heating up vs arcing. > > 73, > > Mark > W7MLG > > On Mon, Jun 1, 2020 at 9:01 PM Bob McGraw K4TAX <[email protected] > <mailto:[email protected]>> wrote: > > Plus there is L1 which is 0.3uH in the circuit and C7 and C8 in the > circuit when in the bypass position. This does not allow the tuner, > even in bypass mode, to work well as an antenna switch on 6M. > > The capacitors in question are not rated for the RF current > experienced under certain load Z conditions. They heat, change > value, > and the SWR creeps up. Allow them to cool and the SWR is back to the > starting point. I usually tweaked mine such that the SWR > started off > a bit high, came down as I transmitted and if transmitting a bit > longer > the SWR increased. Later I got tired of this and changed the > group of > disk ceramic caps to 470 pf Russian doorknob caps. Problem solved. > > 73 > > Bob, K4TAX > > > On 6/1/2020 10:08 PM, Jim Brown wrote: > > his might be it, Peter. ! I've used (and loved) the Ten Tec 229 and > > 238 tuners, but some of their fixed capacitors are under-rated for > > power. This is fairly well known among Ten Tec users, so I read > about > > it somewhere and replaced those in my tuners with caps having > higher > > power ratings. > > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:[email protected] > <mailto:[email protected]> > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > Message delivered to [email protected] > <mailto:[email protected]> > ______________________________________________________________ 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 Message delivered to [email protected] ______________________________________________________________ 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 Message delivered to [email protected]
