Topband: OX/OZ1LXJ QSL
Has anybody received a QSL for OZ1LXJ's operation from Greenland during Sep-Oct, 2013? He made 505 top band contacts. Thanks Udo NI0G _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: Low band noise
Hi Bruce et al Radiated noise from a new wind farm eventually forced us to close down and exit the ZL6QH contest station. A detailed report on the noise levels is available at http://www.zl6qh.com/rf-noise-measurements-quartz-hill-2009-v3.pdf . The ZL6QH wind farm used Siemens 2.3 MW variable speed turbines. We believe the noise was generated by the water cooled electronic power converter technology that was used to convert the variable output of each turbine to the fixed voltage and frequency of the national grid. Our observations suggested that an HF contest station would have be located at least several km from the wind farm to reduce the interference to an acceptable level on the low frequency bands. 73 Brian VK3MI ZL1AZE -- Message: 1 Date: Thu, 20 Feb 2014 13:09:51 -0500 From: Bruce k...@myfairpoint.net To: topband@contesting.com Subject: Topband: Low band noise Message-ID: A683AF2F3AEA44CE9BF4F857A9034DDC@k1fzPC Content-Type: text/plain; charset=iso-8859-1 Thank you for those who emailed information. They basically thought the larger windmill arrays did not generate much noise. One test, checking all bands, was from a mobile K3 with a 9 foot whip antenna. Unless the whip was loaded to 1.8 Mhz it may not pick up much noise at one mile. The most probable windmill installation noise source is the inverter. Smaller home/farm 1 phase type may give off more wideband noise. Some are using transformer-less inverters. Noise is ever increasing in many areas. There is a need to monitor noise sources, and installing more directive receiving antennas. http://www.solacity.com/connections.htm Watch the inverter video for more info. Highly informative. http://www.power-one.com/renewable-energy/products/solar/string-inverters/aurora-uno-single-phase/pvi-30363842-north-america/series _ Topband Reflector Archives - http://www.contesting.com/_topband
Topband: Shunt feeding the Skyneedle - new developments
All Topband list If you've followed my efforts to shunt feed my Skyneedle tower you'll know that I settled with a tap point of 67' and 30 or so of spacing with my feed point reading 42 + j0 ohms. This reading was taken at the interior of my 20 x 30 x 8 steel Hoffman enclosure with the variable cap located outside the enclosure sitting on a plastic 5 gal jug. The output of the variable cap fed into a ceramic feed thru insulator thru the panel to a copper L bracket that mounts the SO 239 connector that I hooked my coax cable to. 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? The other strange situation I'm experiencing is when I connect my Array Solutions static bleed choke to the feed thru insulator at the outside of the panel to ground the resonant frequency jumps to 2.014 MHz at 25 +j0 ohms...remove it entirely and I'm back to my 45 - j11 ohms. I use 1 meg ohm from the feed point to ground on my other verticals with NO change in MFJ analyzer readings. Any comments from the list on these problems? Thanks Carl AG6X _ Topband Reflector Archives - http://www.contesting.com/_topband
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 other strange situation I'm experiencing is when I connect my Array Solutions static bleed choke to the feed thru insulator at the outside of the panel to ground the resonant frequency jumps to 2.014 MHz at 25 +j0 ohms...remove it entirely and I'm back to my 45 - j11 ohms. 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
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-boun...@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 other strange situation I'm experiencing is when I connect my Array Solutions static bleed choke to the feed thru insulator at the outside of the panel to ground the resonant frequency jumps to 2.014 MHz at 25 +j0 ohms...remove it entirely and I'm back to my 45 - j11 ohms. 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
Re: Topband: Shunt feeding the Skyneedle - new developments BTW
BTW. Carl I agree completely with Tom that there's no point in having a static-bleed choke on a grounded shunt fed tower! 73, Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@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 other strange situation I'm experiencing is when I connect my Array Solutions static bleed choke to the feed thru insulator at the outside of the panel to ground the resonant frequency jumps to 2.014 MHz at 25 +j0 ohms...remove it entirely and I'm back to my 45 - j11 ohms. 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
Re: Topband: Low band noise
Hi Brian, Thank you for your input and sorry to find that the windmill farm noise caused ZL6QH to close down. It will become evident that each country will need enforce RF noise limits on windmills, or start rule making if none exist. In the USA complaints to the ARRL should bring guidance in this matter. Some of the low band reflector DXers may wish to ask questions, if that is all right with you. Thanks again, 73 Bruce-K1FZ - Original Message - From: Brian Miller brianmil...@xtra.co.nz To: topband@contesting.com Sent: Friday, February 21, 2014 5:46 PM Subject: Re: Topband: Low band noise Hi Bruce et al Radiated noise from a new wind farm eventually forced us to close down and exit the ZL6QH contest station. A detailed report on the noise levels is available at http://www.zl6qh.com/rf-noise-measurements-quartz-hill-2009-v3.pdf . The ZL6QH wind farm used Siemens 2.3 MW variable speed turbines. We believe the noise was generated by the water cooled electronic power converter technology that was used to convert the variable output of each turbine to the fixed voltage and frequency of the national grid. Our observations suggested that an HF contest station would have be located at least several km from the wind farm to reduce the interference to an acceptable level on the low frequency bands. 73 Brian VK3MI ZL1AZE -- Message: 1 Date: Thu, 20 Feb 2014 13:09:51 -0500 From: Bruce k...@myfairpoint.net To: topband@contesting.com Subject: Topband: Low band noise Message-ID: A683AF2F3AEA44CE9BF4F857A9034DDC@k1fzPC Content-Type: text/plain; charset=iso-8859-1 Thank you for those who emailed information. They basically thought the larger windmill arrays did not generate much noise. One test, checking all bands, was from a mobile K3 with a 9 foot whip antenna. Unless the whip was loaded to 1.8 Mhz it may not pick up much noise at one mile. The most probable windmill installation noise source is the inverter. Smaller home/farm 1 phase type may give off more wideband noise. Some are using transformer-less inverters. Noise is ever increasing in many areas. There is a need to monitor noise sources, and installing more directive receiving antennas. http://www.solacity.com/connections.htm Watch the inverter video for more info. Highly informative. http://www.power-one.com/renewable-energy/products/solar/string-inverters/aurora-uno-single-phase/pvi-30363842-north-america/series _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband
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-cunning...@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-boun...@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 other strange situation I'm experiencing is when I connect my Array Solutions static bleed choke to the feed thru insulator at the outside of the panel to ground the resonant frequency jumps to 2.014 MHz at 25 +j0 ohms...remove it entirely and I'm back to my 45 - j11 ohms. 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
Re: Topband: Shunt feeding the Skyneedle - new developments BTW-P.S.
By the way, Carl. it sounds like you might have eliminated a bit of series inductance when you moved the variable capacitor into the enclosure and you may have picked up a bit of shunt-C by moving it into the metallic enclosure, but you are so close to dead-flat 1:1, that it really doesn't matter. You could just tweak the variable C to minimize the reactance at the load, but -j11 is just fine! As I said earlier your 45-j11 resides near the origin of the chart on a 1.3:1 VSWR circle! Enjoy and have fun! 73, Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Charlie Cunningham Sent: Friday, February 21, 2014 8:30 PM To: 'Tom W8JI'; 'Carl Braun'; '160' Subject: Re: Topband: Shunt feeding the Skyneedle - new developments BTW BTW. Carl I agree completely with Tom that there's no point in having a static-bleed choke on a grounded shunt fed tower! 73, Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@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 other strange situation I'm experiencing is when I connect my Array Solutions static bleed choke to the feed thru insulator at the outside of the panel to ground the resonant frequency jumps to 2.014 MHz at 25 +j0 ohms...remove it entirely and I'm back to my 45 - j11 ohms. 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
Re: Topband: Shunt feeding the Skyneedle - new developments
I'd think your Henry would match that just fine WITHOUT the Nye Viking tuner!! 73, Charlie. K4OTV -Original Message- From: Carl Braun [mailto:carl.br...@lairdtech.com] 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-cunning...@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-boun...@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 other strange situation I'm experiencing is when I connect my Array Solutions static bleed choke to the feed thru insulator at the outside of the panel to ground the resonant frequency jumps to 2.014 MHz at 25 +j0 ohms...remove it entirely and I'm back to my 45 - j11 ohms. 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
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-boun...@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-cunning...@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-boun...@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 other strange situation I'm experiencing is when I connect my Array Solutions static bleed choke to the feed thru insulator at the outside of the panel to ground the resonant frequency jumps to 2.014 MHz at 25 +j0 ohms...remove it entirely and I'm back to my 45 - j11 ohms. 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
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-boun...@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-boun...@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-cunning...@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-boun...@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 other strange situation I'm experiencing is when I connect my Array Solutions static bleed choke to the feed thru insulator at the outside of the panel to ground the resonant frequency jumps to
Re: Topband: Shunt feeding the Skyneedle - new developments
Charlie The cap is no where near maxed out. I'm using approx 150pf of a 1050pf variable cap. Carl -Original Message- From: Charlie Cunningham [mailto:charlie-cunning...@nc.rr.com] Sent: Friday, February 21, 2014 6:37 PM To: Carl Braun; 'Tom W8JI'; '160' 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-boun...@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-cunning...@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-boun...@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 other strange situation I'm experiencing is when I connect my Array Solutions static bleed choke to the feed thru insulator at the outside of the panel to ground the resonant frequency jumps to 2.014 MHz at 25 +j0 ohms...remove it entirely and I'm back to my 45 - j11 ohms. 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
Re: Topband: Shunt feeding the Skyneedle - new developments
Well, Carl, you might pick up a littie less shunt C with the vacuum variable, and if it will provide more capacitance, it will probably allow you to get to j0. I guess if you don't have some other need for the high voltage capability of the vacuum variable, It should surely do the job! If you are at -j11, that means you have tken out enough inductance from the gamma line that you now need a larger capacitor to resonate it. Have fun! 73, Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Carl Braun Sent: Friday, February 21, 2014 10:31 PM To: ZR Cc: Charlie Cunningham; 160 Subject: Re: Topband: Shunt feeding the Skyneedle - new developments Thanks guys The j11 ohms is the best I can get period. I was able to get j0 when the cap was outside of the steel enclosure with a better bandwidth. Maybe I should throw my $400 enclosure and find a fibergla$$ enclosure. But as others have indicated I should probably just live with it. Do you think a smaller (physically) vacuum cap would have less interaction with the steel enclosure. The one I have is only 3 round and 6 long. The air variable I'm using is 13 long and 7 round at mesh Carl AG6X Sent from my iPhone On Feb 21, 2014, at 7:11 PM, ZR z...@jeremy.mv.com wrote: 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-boun...@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-cunning...@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-boun...@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
Re: Topband: Shunt feeding the Skyneedle - new developments
Well, that would surely suggest that you should be able to reach j0, by increasing the series capacitance, Carl, unless there's a shunt-C term that has entered the picture after mouning that big variable capacitor in the metallic enclosure. But, again, why bother! 73, Charlie, K4OTV -Original Message- From: Carl Braun [mailto:carl.br...@lairdtech.com] Sent: Friday, February 21, 2014 10:39 PM To: Charlie Cunningham; 'Tom W8JI'; '160' Subject: RE: Topband: Shunt feeding the Skyneedle - new developments Charlie The cap is no where near maxed out. I'm using approx 150pf of a 1050pf variable cap. Carl -Original Message- From: Charlie Cunningham [mailto:charlie-cunning...@nc.rr.com] Sent: Friday, February 21, 2014 6:37 PM To: Carl Braun; 'Tom W8JI'; '160' 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-boun...@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-cunning...@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-boun...@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 other strange situation I'm experiencing is when I connect my Array Solutions static bleed choke to the feed thru insulator at the outside of the panel to ground the resonant frequency jumps to 2.014 MHz at 25 +j0 ohms...remove it entirely and I'm back to my 45 - j11 ohms. The choke is completely unnecessary with a shunt feed
Re: Topband: Shunt feeding the Skyneedle - new developments
I'm working on the radial field weekly. Here is a theoretical question that results from my particular QTH. The Skyneedle is situated near a secondary blacktop driveway that is in the back of my property. I have to run radials over the blacktop to the rest of the property and, in order to keep things kind of neat, I'm using multi-conductor rotor cable as radials that travel over the blacktop. I have both 6 conductor and 3 conductor control cable that I'm using. I strip back the jacket at the radial ring...fan out the wires 3 apart and attach them to the 1 1/2 copper pipe I'm using as a radial ring around the base of the 'Needle'. Then the radial wires converge back into the cable jacket then travel across the 10' blacktop driveway and then they are removed from the cable jacket where they fan out into the dirt and are buried. Most of these radial wires are 60' to 100' once they leave the jacket. Any problem with what I'm doing here? I understand that it would be better if they fanned out directly from the base but I can have 50+ wires traveling over the blacktop. I was even considering getting an asphalt blade and cutting some channels into the blacktop...burying the jacketed cable into the asphalt and then sealing then in so I'm not running over them or tripping over them when playing Frisbee with the hound. My Guatemalan yard worker has been burying radial wires for the last month and thinks that I'm LOCO but he likes getting paid at the end of the day. As we speak I have a total of 34 radials with the shortest being 30' with the longest at 100'. Most of them are 60-70'. Four of them are tied into my 40m phased array radial field comprised of 90-100 radials under each antenna ranging from 40' to 80'. I can change the height of these verticals from 33' for 40m to 66' for 80m. 1/2 wl spacing on 40 and 1/4 wl spacing on 80. Carl AG6X -Original Message- From: Charlie Cunningham [mailto:charlie-cunning...@nc.rr.com] Sent: Friday, February 21, 2014 7:36 PM To: 'ZR'; Carl Braun; '160' 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-boun...@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-boun...@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.
Re: Topband: Shunt feeding the Skyneedle - new developments
Hi, Carl Well, I think that what you are doing with your radials should be OK. I guess I'd rather get them under the asphalt if I could where they wouldn't get torn up or b a trip hazard. BTW I I was playing with your match on the Smith Chart and if you'll add about 1 uHy inductance in series with the connector (SO-239?) where you feedline leaves the enclosure, that will take you to 45 +j0, but I'd be concerned about incurring more losses in the inductor than any tiny mismatch loss from the -j11 term. I probably wouldn't do it. 73, Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Carl Braun Sent: Friday, February 21, 2014 10:56 PM To: Charlie Cunningham; 'ZR'; '160' Subject: Re: Topband: Shunt feeding the Skyneedle - new developments I'm working on the radial field weekly. Here is a theoretical question that results from my particular QTH. The Skyneedle is situated near a secondary blacktop driveway that is in the back of my property. I have to run radials over the blacktop to the rest of the property and, in order to keep things kind of neat, I'm using multi-conductor rotor cable as radials that travel over the blacktop. I have both 6 conductor and 3 conductor control cable that I'm using. I strip back the jacket at the radial ring...fan out the wires 3 apart and attach them to the 1 1/2 copper pipe I'm using as a radial ring around the base of the 'Needle'. Then the radial wires converge back into the cable jacket then travel across the 10' blacktop driveway and then they are removed from the cable jacket where they fan out into the dirt and are buried. Most of these radial wires are 60' to 100' once they leave the jacket. Any problem with what I'm doing here? I understand that it would be better if they fanned out directly from the base but I can have 50+ wires traveling over the blacktop. I was even considering getting an asphalt blade and cutting some channels into the blacktop...burying the jacketed cable into the asphalt and then sealing then in so I'm not running over them or tripping over them when playing Frisbee with the hound. My Guatemalan yard worker has been burying radial wires for the last month and thinks that I'm LOCO but he likes getting paid at the end of the day. As we speak I have a total of 34 radials with the shortest being 30' with the longest at 100'. Most of them are 60-70'. Four of them are tied into my 40m phased array radial field comprised of 90-100 radials under each antenna ranging from 40' to 80'. I can change the height of these verticals from 33' for 40m to 66' for 80m. 1/2 wl spacing on 40 and 1/4 wl spacing on 80. Carl AG6X -Original Message- From: Charlie Cunningham [mailto:charlie-cunning...@nc.rr.com] Sent: Friday, February 21, 2014 7:36 PM To: 'ZR'; Carl Braun; '160' 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-boun...@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-boun...@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
