If you are really interested in 40M only, why on earth don't you simplify your life and get rid of the tuners, the ladderline and the BL2. Run coax from the antenna spigot on the radio to the antenna. Coil up a few turns of it at the feed point if you insist on a balun (I don't necessarily), trim the length of the wire for minimum SWR at your frequency of interest and get on and operate.
Wes N7WS --- On Sat, 1/16/10, djmd <d...@fuse.net> wrote: > From: djmd <d...@fuse.net> > Subject: Re: [Elecraft] [OT] High SWR on 20 and 40 > To: elecraft@mailman.qth.net > Date: Saturday, January 16, 2010, 3:05 PM > > Hi James, > > Thanks so much for the extremely informative reply! I will > dig deep into a > lot of your suggestions later tonight. I think I may have > overcomplicated > the issue, so let me see if I can give it a shakedown. > > First off, lets forget everything besides 40m. That's > really the band I am > concerned with first and foremost. > > Before Elecraft came into my life, I was using a Yaesu > FT840 with an MFJ941E > tuner. Coax (10' or so) out of the tuner, through the > floor, into a barrel > that goes through cementboard to the outside. From there, > short coax up to a > W2DU 4:1 current balun. Then 16' or so of windowline, and > the dipole up > about 20', about 67' long. I have a very restricted yard > for antennas and > just wanted to get on the air. > > Anyway, after some poking and prodding I was able to > consistently tune up on > 40m fairly well, 1.5 or less. I made several CW contacts > across the country > as well as Canada and South America. > > Then I built the KX1 with the autotuner, and was not able > to get under 5:1 > from the same point with all the same components in place. > No big deal, I > didn't intend on using the KX1 in the 'shack' anyway. But > then I built the > K2/KAT2, and was getting pretty much the same result. As it > stands right > now, I cannot break below 9.9:1 on the KAT2 on 40m from the > shack. I've > tried different coax types and lengths on each side of the > barrel and have > seen no improvement. Also, it doesn't matter which balun I > use, or whether I > select 1:1 or 4:1 on the BL2. Results are the same. > > Now, when I attach the K2 directly to the balun (now an > Elecraft BL2) I can > get a great match on 40m. As I can add a very short piece > between the K2 and > the balun with no ill effect, but once the coax is longer > than about 5', the > SWR shoots up. > > I picked up an analyzer today (259B). It's my first one, > and I hardly know > what I'm doing, but I can tell you right off the bat that > whether I attach > it to the coax in the shack, or directly to the balun, it's > appearing to be > resonant at the same 3 places. Around 10mhz, 20mhz, and > 26mhz. If there is > any other information you would like to know from the > analyzer at any > specific frequency and connnection point, please let me > know. > > I hope this helps... I sincerely appreciate everyone's > assistance. I'm still > learning and it's nice to have a place to get good info and > not made to feel > like I'm an idiot. > :drunk::confused: > > > > > -- > View this message in context: > http://n2.nabble.com/High-SWR-on-20-and-40-tp4403006p4406096.html > Sent from the [OT] mailing list archive at Nabble.com. > ______________________________________________________________ > 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
