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## Re: Topband: Shunt feeding the Skyneedle - new developments

 To: "'Carl'" , "'Carl Braun'" , "'160'" Re: Topband: Shunt feeding the Skyneedle - new developments "Charlie Cunningham" Sat, 22 Feb 2014 11:03:36 -0500 mailto:topband@contesting.com>
 ```Well, I agree with all that, Carl. But Carl Braun, was reading "dead-flat" 1:1 at the transmitter end of his cable. I believe he is done!! The antenna Q is what it is! As for "improving his 2:1 VSWR bandwidth" he could reduce his radial field and increase his ground losses to improve his 2:1 "BW" - but I believe that to be self-defeating!! I'm not "missing your point" - I just don't see what you'd change to improve on a "flat" line! Carl is well past the point of "diminishing returns"! The math doesn't "lie"! Charlie, K4OTV -----Original Message----- From: Topband [mailto:topband-bounces@contesting.com] On Behalf Of Carl Sent: Saturday, February 22, 2014 10:41 AM To: Charlie Cunningham; 'Carl Braun'; '160' Subject: Re: Topband: Shunt feeding the Skyneedle - new developments Charlie youre continually missing the point; ignore cable loss period. The only issue is what impedance does the amp see from lets say 1800 to 1900 KHz? AND can the amp load into it without a problem at full power? This is a system issue, not just what is measured at the antenna and needs to be addressed that way. Put all that info into your program and post the results. Saying that a 1.3 VSWR at reasonance at the antenna is sufficient is too simplistic. Compute the VSWR at the amp with whatever length of coax is actually used over the lower 100 KHz with a range of " at resonance" VSWR's. Carl KM1H ----- Original Message ----- From: "Charlie Cunningham" To: "'Carl'" ; "'Carl Braun'" ; "'160'" Sent: Saturday, February 22, 2014 9:57 AM Subject: RE: Topband: Shunt feeding the Skyneedle - new developments Well, Carl the looses in 70' or even 200' of LMR-400 are so low at 1.8 MHz, even at 2.0:1 or 3.0 :1, if he can match it at the transmitter end of the line, it really doesn't matter! Charlie, K4OTV -----Original Message----- From: Topband [mailto:topband-bounces@contesting.com] On Behalf Of Carl Sent: Saturday, February 22, 2014 9:46 AM To: Charlie Cunningham; 'Carl Braun'; '160' Subject: Re: Topband: Shunt feeding the Skyneedle - new developments That 1.3 is only at ONE frequency Charlie, he is not crystal controlled. What is the 2:1 bandwidth at the amp? Carl KM1H ----- Original Message ----- From: "Charlie Cunningham" To: "'Carl'" ; "'Carl Braun'" ; "'160'" Sent: Saturday, February 22, 2014 9:23 AM Subject: RE: Topband: Shunt feeding the Skyneedle - new developments I don't expect that ANY of those are valid concerns at 1.3:1 VSWR!! -----Original Message----- From: Topband [mailto:topband-bounces@contesting.com] On Behalf Of Carl Sent: Saturday, February 22, 2014 9:14 AM To: Charlie Cunningham; 'Carl Braun'; '160' Subject: Re: Topband: Shunt feeding the Skyneedle - new developments Im not concerned by what is measured at the matching unit or a miniscule cable loss; just what is transformed back to the amp and its ability to load at full power without arcing, running out of or having too much fixed padder C during QSY's. Contests do not stay just in the narrow CW 50 KHz "window" and not having to use an external tuner is a big plus. Ive always modified my amps to work with my antennas on 160 and 80/75. Carl KM1H ----- Original Message ----- From: "Charlie Cunningham" To: "'ZR'" ; "'Carl Braun'" ; "'160'" Sent: Friday, February 21, 2014 10:35 PM Subject: Re: Topband: Shunt feeding the Skyneedle - new developments Well, if I recall correctly, Carl, Carl said his feedline was about 70' of LMR-400, so even at 2 2:1 or 2.5:1 VSWR, the excess losses in 70' of LMR-400 at 1.8 MHz are almost 0, so if he can match it OK at the transmitter end of the line- no real point in making heroic efforts to achieve a "perfect" match! He'd gain more by working on his radial field, and he really should do that before doing any more tuning because improving the radials WILL affect the antenna impedance. 73, Charlie, K4OTV -----Original Message----- From: Topband [mailto:topband-bounces@contesting.com] On Behalf Of ZR Sent: Friday, February 21, 2014 10:11 PM To: Charlie Cunningham; 'Carl Braun'; '160' Subject: Re: Topband: Shunt feeding the Skyneedle - new developments The only benefit of getting it better would be a bit more 2:1 VSWR bandwidth to keep the amp happy but even then there is sometimes a gotcha when tuning an antenna. Carl KM1H Subject: Re: Topband: Shunt feeding the Skyneedle - new developments Well, you can do all that, Carl But if your series variable capacitor is not maxed out (fully meshed) if you can increase the capacitance enough to get to j0, you would be at 45 +j0 and on a 1.1:1 VSWR circle. No point int trying to do better than that!! Otherwise, just increase the series capacitance to bring that -j11 as close to j0 as possible and take that! You'd be so near perfect that there would be no real point in going further! Your time and efforts might be better spent working on your radial field! 73, Charlie, K4OTV -----Original Message----- From: Topband [mailto:topband-bounces@contesting.com] On Behalf Of Carl Braun Sent: Friday, February 21, 2014 8:46 PM To: Charlie Cunningham; 'Tom W8JI'; '160' Subject: Re: Topband: Shunt feeding the Skyneedle - new developments Thanks to all who replied Tom W8JI, your comments on the metallic panel and the static bleed choke make sense. I was so pleased with the FLAT SWR reading with the variable cap outside the panel but I guess I can live with the slight SWR. (Thanks Charlie K4OTV). I have a Nye Viking monster tuner but I hate to use it as my Henry amp seems to load strangely when I have it inline so I think I'll just live without it. Can I add some coax (coiled) to bring the X down on the -j11 reading? I did this with the old Telrex and brought the X right down and out of the pic. I'm sure Ill need much more than I would on 14MHz but I think I'd like to try anyway. I'm still going to drop the tower down and add two more gamma wires to create a cage and I still have the option of pulling the gamma wire(s) away from the tower another 8-10 inches to add a few more ohms to the equation. I'm having fun with the experiment. Right now I'm hearing the beginnings of the SSB contest with N7GP, WD5COV, W6YI with the big signals so far. XE is the only DX I've heard. Lots of stateside calling stateside Carl AG6X -----Original Message----- From: Charlie Cunningham [mailto:charlie-cunningham@nc.rr.com] Sent: Friday, February 21, 2014 5:21 PM To: 'Tom W8JI'; Carl Braun; '160' Subject: RE: Topband: Shunt feeding the Skyneedle - new developments Well, Carl I plotted your 45-j11 load on a Smith Chart (normalized to 50 ohms) and it's very near the origin on a 1.3:1 VSWR circle. Since you have a relatively short feedline of LMR-400, You should be able to just tune it out at the transmitter end of the line, and the LMR-400 line will be operating at such a very low SWR (around 1.3:1 that the excess loss from a 1.3:1 VSWR at 160 is completely trivial and negligible! It may not be completely "intellectually satisfying to have -j11 of reactance at the load, but it should match easily and the antenna should work very well! Enjoy! Sounds like that Array solutions static bleed is not as high in impedance as we might wish! A large resistance might give you more satisfactory results! GL! Enjoy! 73, Charlie, K4OTV -----Original Message----- From: Topband [mailto:topband-bounces@contesting.com] On Behalf Of Tom W8JI Sent: Friday, February 21, 2014 8:02 PM To: Carl Braun; '160' Subject: Re: Topband: Shunt feeding the Skyneedle - new developments Since then I've moved the variable capacitor inside the panel and mounted it to a ¾" think Plexiglas sheet mounted to the back plane with nylon bolts and washers. There is a 1" air gap between the Plexiglas and the backplane. I now have seen the 42+j0 ohms change to 45 - j11 ohms...that's the lowest reactance I can tune the capacitor for. Not really sure if its +j11 ohms or - j11 ohms but I assume if the reading was + j11 I could continue to tune it out with the capacitor but I cant. Does the capacitor not play well with a steel enclosure?>>>> Any enclosure will change things, especially a metallic enclosure. Just readjust the cap. <<<>> The choke is completely unnecessary with a shunt feed tower. It won't help a thing, so leave it out. 73 Tom _________________ Topband Reflector Archives - http://www.contesting.com/_topband _________________ Topband Reflector Archives - http://www.contesting.com/_topband _________________ Topband Reflector Archives - http://www.contesting.com/_topband ----- No virus found in this message. Checked by AVG - www.avg.com Version: 2014.0.4335 / Virus Database: 3705/7115 - Release Date: 02/21/14 _________________ Topband Reflector Archives - http://www.contesting.com/_topband _________________ Topband Reflector Archives - http://www.contesting.com/_topband ----- No virus found in this message. Checked by AVG - www.avg.com Version: 2014.0.4335 / Virus Database: 3705/7115 - Release Date: 02/21/14 _________________ Topband Reflector Archives - http://www.contesting.com/_topband ----- No virus found in this message. Checked by AVG - www.avg.com Version: 2014.0.4335 / Virus Database: 3705/7116 - Release Date: 02/22/14 _________________ Topband Reflector Archives - http://www.contesting.com/_topband ----- No virus found in this message. Checked by AVG - www.avg.com Version: 2014.0.4335 / Virus Database: 3705/7116 - Release Date: 02/22/14 _________________ Topband Reflector Archives - http://www.contesting.com/_topband _________________ Topband Reflector Archives - http://www.contesting.com/_topband ```
 Current Thread Re: Topband: Shunt feeding the Skyneedle - new developments, (continued) Re: Topband: Shunt feeding the Skyneedle - new developments, Charlie Cunningham Re: Topband: Shunt feeding the Skyneedle - new developments, Carl Braun Re: Topband: Shunt feeding the Skyneedle - new developments, Charlie Cunningham Re: Topband: Shunt feeding the Skyneedle - new developments, Tom W8JI Re: Topband: Shunt feeding the Skyneedle - new developments, Charlie Cunningham Re: Topband: Shunt feeding the Skyneedle - new developments, Carl Re: Topband: Shunt feeding the Skyneedle - new developments, Charlie Cunningham Re: Topband: Shunt feeding the Skyneedle - new developments, Carl Re: Topband: Shunt feeding the Skyneedle - new developments, Charlie Cunningham Re: Topband: Shunt feeding the Skyneedle - new developments, Carl Re: Topband: Shunt feeding the Skyneedle - new developments, Charlie Cunningham <= Re: Topband: Shunt feeding the Skyneedle - new developments, Roger D Johnson Re: Topband: Shunt feeding the Skyneedle - new developments, Charlie Cunningham Re: Topband: Shunt feeding the Skyneedle - new developments, Carl Re: Topband: Shunt feeding the Skyneedle - new developments, Carl Braun Message not availableRe: Topband: Shunt feeding the Skyneedle - new developments, Carl Braun Re: Topband: Shunt feeding the Skyneedle - new developments, Richard (Rick) Karlquist Re: Topband: Shunt feeding the Skyneedle - new developments, JC N4IS Re: Topband: Shunt feeding the Skyneedle - new developments, Charlie Cunningham Re: Topband: Shunt feeding the Skyneedle - new developments, Tom W8JI Re: Topband: Shunt feeding the Skyneedle - new developments, Charlie Cunningham