KX2 Antenna Curiosity
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Is there any modern-day equivalent to the old Johnson Matchbox? I use
several different MFJ tuners with good results. My favorite is the "Differential-T" 986 which tunes everything with very little effort. I don't actually know how efficient it is but it tunes my 132' doublet fed with 450 ohm ladder line very well. I use the antenna mostly on 160-80-60-40-30 where it seems to perform well. The ladder-line comes to a 1:1 high power balun just outside the shack and 10' of rg213 comes inside to the tuner. The only interesting observation is that it seems noisier than my multi-band trapped dipole - as much as 1-2 s units sometimes. Otherwise, if I only had one antenna it would be the doublet. Very versatile. The tuner gives the rig a good under 1.5:1 match 160 through 6. 73, Doug -- KJØF On 10/10/2019 11:59 PM, Vic Rosenthal wrote: > You bet. The Johnson Matchbox is as good as any expensive band pass filter. > > Victor 4X6GP > >> On 11 Oct 2019, at 2:57, Joe Subich, W4TV <[hidden email]> wrote: >> >> >> The one "multiband" antenna one can use in a multi-transmitter >> configuration is the flat-top with open wire feeders and a >> *Link coupled* tuner. The link coupled tuner is a bandpass filter >> that significantly reduces harmonic/broadband noise just like the >> "Q" of a single band antenna. >> >> 73, >> >> ... Joe, W4TV >> >> >>> On 2019-10-10 7:44 PM, Don Wilhelm wrote: >>> Bob, >>> Bandpass filters at each station will help a lot, but they do not have infinite out of band rejection. >>> There is still a huge benefit with single band antennas. My club uses both. >>> Last Field Day (3F operation) one station got on the air with a multiband vertical, and all other operators jumped on that operator to shut him down quickly! The multi-band antenna radiated harmonics of the radio. Even though the transmitter met the -43 dB harmonic required by the FCC, the proximity of the multiband antenna to other antennas caused problems (that station was not using a bandpass filter). >>> So for Field Day multi-station operation, single band antennas, bandpass filters and transmitters with low phase noise are important. We were not able to orient the antennas end to end due to space considerations at the EOC site, so we had to compromise on that, which makes the other factors very important. >>> I need to point out that as an experiment, a 2nd station used an antenna on 20 meters separated from the main 20 meters, and we were able to operate one on CW (K3) at the same time as the other station (Icom) used digital and SSB modes. We had some mutual interference, but it was minimal. The K3 did not interfere much with the Icom due to the K3's low phase noise, but the Icom did raise the background noise level on the K3. >>> 73, >>> Don W3FPR >> ______________________________________________________________ >> Elecraft mailing list >> Home: http://mailman.qth.net/mailman/listinfo/elecraft >> Help: http://mailman.qth.net/mmfaq.htm >> Post: mailto:[hidden email] >> >> This list hosted by: http://www.qsl.net >> Please help support this email list: http://www.qsl.net/donate.html >> Message delivered to [hidden email] > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:[hidden email] > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > Message delivered to [hidden email] > 73 de Doug -- KJ0F ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] |
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Might I suggest a Common Mode Filter, such as that sold my myantennas.com?
My standby antenna is an endfed half-wave from the same source. It hangs from the eve corner and is noisy - the kind of noise that comes from today's modern household. I put a CMC Filter on it right at the bulkhead here in the shack. The antenna is now as quiet as my NVIS a hundred feet from the house - which is no local noise at all. I have used the coax through the wall to a balun and 4" feeder with excellent success with a PalStar AT2KD (very similar to the MFJ tuner you mentioned). ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] |
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In reply to this post by Doug Person-5
On 2019-10-11 3:19 PM, Doug Person wrote: > > My favorite is the "Differential-T" 986 which tunes everything with > very little effort. Any of the many "T" (single shunt coil, multiple series capacitors) network tuners are high pass networks. They do very little to suppress harmonics and/or phase noise above the transmit frequency. 73, ... Joe, W4TV On 2019-10-11 3:19 PM, Doug Person wrote: > Is there any modern-day equivalent to the old Johnson Matchbox? I use > several different MFJ tuners with good results. My favorite is the > "Differential-T" 986 which tunes everything with very little effort. I > don't actually know how efficient it is but it tunes my 132' doublet fed > with 450 ohm ladder line very well. I use the antenna mostly on > 160-80-60-40-30 where it seems to perform well. The ladder-line comes to > a 1:1 high power balun just outside the shack and 10' of rg213 comes > inside to the tuner. The only interesting observation is that it seems > noisier than my multi-band trapped dipole - as much as 1-2 s units > sometimes. Otherwise, if I only had one antenna it would be the doublet. > Very versatile. The tuner gives the rig a good under 1.5:1 match 160 > through 6. > 73, Doug -- KJØF > ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] |
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In reply to this post by Bill-3
On 10/11/2019 2:00 PM, Bill wrote:
> Might I suggest a Common Mode Filter, such as that sold my myantennas.com All the mumbo-jumbo on that site tells me that they selling snake oil. FAR better, and much less expensive, wind your own using these guidelines. k9yc.com/2018Cookbook.pdf 73, Jim K9YC ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] |
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Of course you do! I was only reporting what I have found to be effective
in my particular circumstance. Further, not everyone has the manual dexterity or prowess to build things themselves - hence, they purchase as needed. Hopefully, without recrimination. Bill W2BLC on the air for over 60 years! ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] |
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Without context you are not making any sense. Quoted material would be considerate.
Sent from my iPhone > On Oct 12, 2019, at 08:45, Bill <[hidden email]> wrote: > > Of course you do! I was only reporting what I have found to be effective in my particular circumstance. > > Further, not everyone has the manual dexterity or prowess to build things themselves - hence, they purchase as needed. Hopefully, without recrimination. > > Bill W2BLC on the air for over 60 years! > > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:[hidden email] > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > Message delivered to [hidden email] ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] |
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