Re: Topband: Inverted L improvements - Part 3 (now with data)
Todd, have you been tracking your antenna system's performance using reversebeacon after your sunset? I'm guessing that your sunset is circa 0300Z. Last night (Jan 24) you were picked up at 9 western skimmers, perhaps the furthest ones from you being WB6BEE and the VE6's. Based on my experience, that this would be expected performance for a good 160M transmit antenna at 5W level on a quiet night. (I certainly don't have a TX 4-square but I've been in top 10 of several 160M contests). As a cross-comparison on Tuesday night I was CQ'ing at 5W in the NAQCC 160M Sprint from my W3 location, and I was picked up by skimmers all over the east coast and by a few in 9-land and 0-land. Now a small skimmer data set is not the best way in the world to get absolute antenna performance results. But with some caveats, A/B comparisons (using same receiver site at nearby times and frequencies) are possible between two of your own antennas, or between your station and a nearby station. http://reversebeacon.net/dxsd1/dxsd1.php?f=0=nr7rr=dx N7TUG NR7RR 1826.0 CW CQ [LoTW] 12 dB 20 wpm 0859z 24 Jan VE6WZ NR7RR 1826.0 CW CQ [LoTW] 24 dB 20 wpm 0859z 24 Jan VE6JY NR7RR 1826.0 CW CQ [LoTW] 31 dB 20 wpm 0859z 24 Jan K2PO-7 NR7RR 1826.0 CW CQ [LoTW] 18 dB 20 wpm 0859z 24 Jan WA7LNW NR7RR 1826.0 CW CQ [LoTW] 19 dB 20 wpm 0859z 24 Jan WB6BEE NR7RR 1826.0 CW CQ [LoTW] 13 dB 20 wpm 0859z 24 Jan N7TR NR7RR 1826.0 CW CQ [LoTW] 25 dB 20 wpm 0859z 24 Jan N6TV NR7RR 1817.0 CW CQ [LoTW] 6 dB 20 wpm 0856z 24 Jan N7TUG NR7RR 1816.0 CW CQ [LoTW] 11 dB 20 wpm 0706z 24 Jan N6TV NR7RR 1816.0 CW CQ [LoTW] 8 dB 20 wpm 0705z 24 Jan NC7J NR7RR 1824.0 CW CQ [LoTW] 5 dB 20 wpm 0328z 24 Jan Tim N3QE > > _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Re: Topband: Inverted L improvements - Part 3 (now with data)
How about even lay it down? Joe WB9SBD Sig The Original Rolling Ball Clock Idle Tyme Idle-Tyme.com http://www.idle-tyme.com On 1/23/2019 7:14 PM, Jeff Blaine wrote: Disconnect the other antenna. Let it float. 73/jeff/ac0c alpha-charlie-zero-charlie www.ac0c.com On 23-Jan-19 6:02 PM, Todd Goins wrote: Okay, after many requests, on and off list, I disconnected the 43' T 160m antenna at its feed point and for good measure I disconnected the coax feedline from the system too. It made a pretty substantial difference in the measurements. The 1.5 SWR range is now only about 35 kHz wide but the 2.0 SWR range is still 100 kHz which is probably still too wide. Freq SWR R X Z 1800 1.9 31.8 -18.6 36.8 1810 1.7 32.5 -14.1 35.4 1820 1.6 33.3 -9.6 34.7 1830 1.5 33.9 -5.3 34.3 1840 1.45 34.6 -0.7 34.6 1850 1.43 35.5 3.9 35.7 1860 1.47 36.1 9.0 37.2 1870 1.6 37.0 13.9 39.5 1880 1.7 37.8 18.9 42.3 1890 1.8 38.8 24.0 45.6 1900 2 39.9 29.5 49.6 1910 2.2 41.1 34.5 53.7 1920 2.4 42.6 40.5 58.8 1940 2.8 44.7 51.4 68.1 1960 3.4 47.6 63.0 78.9 I'll test it on the air tonight (using FT-8 and the RBN) with the 43' antenna disconnected. Perhaps it will be better? The numbers look better, right? Should I ground the 43' antenna instead of leaving it floating? Thanks guys. 73, Todd - NR7RR _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Re: Topband: Inverted L improvements - Part 3 (now with data)
Disconnect the other antenna. Let it float. 73/jeff/ac0c alpha-charlie-zero-charlie www.ac0c.com On 23-Jan-19 6:02 PM, Todd Goins wrote: Okay, after many requests, on and off list, I disconnected the 43' T 160m antenna at its feed point and for good measure I disconnected the coax feedline from the system too. It made a pretty substantial difference in the measurements. The 1.5 SWR range is now only about 35 kHz wide but the 2.0 SWR range is still 100 kHz which is probably still too wide. Freq SWR RX Z 1800 1.9 31.8 -18.6 36.8 1810 1.7 32.5 -14.1 35.4 1820 1.6 33.3 -9.6 34.7 1830 1.5 33.9 -5.3 34.3 1840 1.45 34.6 -0.7 34.6 1850 1.43 35.5 3.9 35.7 1860 1.47 36.1 9.0 37.2 1870 1.6 37.0 13.9 39.5 1880 1.7 37.8 18.9 42.3 1890 1.8 38.8 24.0 45.6 1900 2 39.9 29.5 49.6 1910 2.2 41.1 34.5 53.7 1920 2.4 42.6 40.5 58.8 1940 2.8 44.7 51.4 68.1 1960 3.4 47.6 63.0 78.9 I'll test it on the air tonight (using FT-8 and the RBN) with the 43' antenna disconnected. Perhaps it will be better? The numbers look better, right? Should I ground the 43' antenna instead of leaving it floating? Thanks guys. 73, Todd - NR7RR _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Re: Topband: Inverted L improvements - Part 3 (now with data)
Okay, after many requests, on and off list, I disconnected the 43' T 160m antenna at its feed point and for good measure I disconnected the coax feedline from the system too. It made a pretty substantial difference in the measurements. The 1.5 SWR range is now only about 35 kHz wide but the 2.0 SWR range is still 100 kHz which is probably still too wide. Freq SWR RX Z 1800 1.9 31.8 -18.6 36.8 1810 1.7 32.5 -14.1 35.4 1820 1.6 33.3 -9.6 34.7 1830 1.5 33.9 -5.3 34.3 1840 1.45 34.6 -0.7 34.6 1850 1.43 35.5 3.9 35.7 1860 1.47 36.1 9.0 37.2 1870 1.6 37.0 13.9 39.5 1880 1.7 37.8 18.9 42.3 1890 1.8 38.8 24.0 45.6 1900 2 39.9 29.5 49.6 1910 2.2 41.1 34.5 53.7 1920 2.4 42.6 40.5 58.8 1940 2.8 44.7 51.4 68.1 1960 3.4 47.6 63.0 78.9 I'll test it on the air tonight (using FT-8 and the RBN) with the 43' antenna disconnected. Perhaps it will be better? The numbers look better, right? Should I ground the 43' antenna instead of leaving it floating? Thanks guys. 73, Todd - NR7RR _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Re: Topband: Inverted L improvements - Part 3 (now with data)
Dont get discouraged by all this for sure What I see as fly in the ointment is another 160 antenna close by with another radial system, Anyone of you gurus ever figure what putting power into a 160 antenna does with another one within feet of it? Imagine power going out, and right back into the other one, being burned up in loss.. Its like having a parasitic element sitting there and screwing up your entire attempts. Wonder why the SWR is broad, your tuning two antennas, any one who has ever tried to tune a 4 square with all elements up knows it cannot be done actually. Take down the short 160 antenna or find a way to detune it far far from 160, and then take some measurements. Come on expurts look at the whole picture not be tunnel visioned, 73 Merv K9FD Both Merv and Guy are correct here. Perhaps this antenna doesn't ever have a chance at being any good due to the suburban area and lot size that I'm constrained by. Within a 250ft radius (huge!) there is as follows: 80m dipole, 40m dipole, 30m dipole, 20m dipole, 15m dipole, 20m yagi, and the original 43' tall T antenna for 160m and its radial system. Also, the house is easily within 250ft. Most certainly the radial systems, although not physically connected to each other, are let's say "mingling". So perhaps this tall wire was doomed from the outset? I was so encouraged that the 43' T worked so well for what it was and the small amount of effort it took to get converted to 160m that maybe a taller version would be substantially better. That's how this saga started. Maybe the real answer after time/effort/money expended and all of your advise is that it isn't going to get any better in my environment? At this point the best path forward may be to just remove the tall wire and reroute all of the new radials (over 2000ft) to the original 43' T's radial plate and with any luck make it play better as a result? Todd - NR7RR Way back some where around the original posting did he not say he had 2 160 antennas up and they are close to each other? a short vertical and this antenna? If so what is the short vertical doing, is it floating or grounded or hooked to the ground system yet, what is its status? Would make all the difference in the world if the short 160 vertical is any where around yet. 73 Merv K9FD * Have to pay attention to everything he is reporting. He added a feedpoint *>* choke per K9YC at the same time. Which may, depending on the physical *>* connections at his feedpoint, have removed the feedline shield as an *>* alternate “radial” in parallel with the increasing but still not full size *>* radial system. *>>* That indicates that his ground characteristics could be well into the *>* “poor” end of the range where ground radial deficiencies are multiplied and *>* emphasized. *>>* His SWR bandwidth narrowed slightly. Leaving a strong possibility that *>* there was an improvement in desired radiated pattern. *>>* There remains the question of every conductor in a 250 foot radius, *>* including a tower? There remains the question of large dielectric masses *>* close by. *>>* 73, Guy K2AV * -- _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Re: Topband: Inverted L improvements - Part 3 (now with data)
As always Frank makes good points. In my case my one lowly tower is 90 feet from the inverted-L and in fact supports the horizontal wire. It's much too short to exhibit any resonance near topband, but I have observed an interesting effect. The tower also supports a pair of inverted-vee dipoles, fed in parallel, one for 40 the other for 80. With a vector analyzer I can sweep the inverted-L and looking at the trace on a Smith chart and see a little discontinuity around 1.8 MHz that goes away if I lower the vee to the ground or terminate the shack end of the coax. It's a really minor effect and apparent;y not even an intellectual curiosity as I've not bothered to investigate it further. It does point out however, that "detuning" by leaving things open circuit isn't necessarily the way to go. Wes N7WS On 1/23/2019 3:45 PM, donov...@starpower.net wrote: Hi Todd, In my opinion you're giving up too easily on your tall antenna. I suggest that you focus more on evaluating its on-the-air performance , and not focus as intently its feed point impedance and VSWR bandwidth. I hope you've been measuring the impedance and bandwidth of your tall antenna with your 43 foot vertical disconnecte d from its both its 160 meter matching components and its feed line, otherwise it will interact very strongly with your tall antenna. Very few of us have the opportunity to install our 160 meter antennas a thousand feet or more from other antennas and tall towers. As a result, the feed point impedance and other characteristics of our antennas can't possibly match theoretical values. Nonetheless, we enjoy our imperfect antennas with their imperfect soil conditions. I hope you'll enjoy yours too. 73 Frank W3LPL _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Re: Topband: Inverted L improvements - Part 3 (now with data)
Hey Todd, What happens to your Inverted L's SWR curve if you short your other 160m antenna (the 43'-T) to ground, or otherwise detune it somehow?..could be you're onto something..not sure. Wide SWR's like that generally point to huge ground losses. I just can't get over how freeging wide your SWR curve *(and frankly I am a little surprised more folks haven't weighed in on this thread) Mike VE9AA NR7RR: So perhaps this tall wire was doomed from the outset? I was so encouraged that the 43' T worked so well for what it was and the small amount of effort it took to get converted to 160m that maybe a taller version would be substantially better At this point the best path forward may be to just remove the tall wire and reroute all of the new radials (over 2000ft) to the original 43' T's radial plate and with any luck make it play better as a result? Todd - NR7RR Mike, Coreen & Corey Keswick Ridge, NB _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Re: Topband: Inverted L improvements - Part 3 (now with data)
Hi Todd, In my opinion you're giving up too easily on your tall antenna. I suggest that you focus more on evaluating its on-the-air performance , and not focus as intently its feed point impedance and VSWR bandwidth. I hope you've been measuring the impedance and bandwidth of your tall antenna with your 43 foot vertical disconnecte d from its both its 160 meter matching components and its feed line, otherwise it will interact very strongly with your tall antenna. Very few of us have the opportunity to install our 160 meter antennas a thousand feet or more from other antennas and tall towers. As a result, the feed point impedance and other characteristics of our antennas can't possibly match theoretical values. Nonetheless, we enjoy our imperfect antennas with their imperfect soil conditions. I hope you'll enjoy yours too. 73 Frank W3LPL - Original Message - From: "Todd Goins" To: topband@contesting.com, 676a8e87-aec6-9ead-1297-0bdb1f0a7...@gmail.com Sent: Wednesday, January 23, 2019 9:09:19 PM Subject: Re: Topband: Inverted L improvements - Part 3 (now with data) Both Merv and Guy are correct here. Perhaps this antenna doesn't ever have a chance at being any good due to the suburban area and lot size that I'm constrained by. Within a 250ft radius (huge!) there is as follows: 80m dipole, 40m dipole, 30m dipole, 20m dipole, 15m dipole, 20m yagi, and the original 43' tall T antenna for 160m and its radial system. Also, the house is easily within 250ft. Most certainly the radial systems, although not physically connected to each other, are let's say "mingling". So perhaps this tall wire was doomed from the outset? I was so encouraged that the 43' T worked so well for what it was and the small amount of effort it took to get converted to 160m that maybe a taller version would be substantially better. That's how this saga started. Maybe the real answer after time/effort/money expended and all of your advise is that it isn't going to get any better in my environment? At this point the best path forward may be to just remove the tall wire and reroute all of the new radials (over 2000ft) to the original 43' T's radial plate and with any luck make it play better as a result? Todd - NR7RR >Way back some where around the original posting did he not say he had >2 160 antennas up and they are close to each other? a short vertical and >this antenna? If so what is the short vertical doing, is it floating or >grounded or hooked to the ground system yet, what is its status? >Would make all the difference in the world if the short 160 vertical is >any where around yet. > >73 Merv K9FD >* Have to pay attention to everything he is reporting. He added a feedpoint *>* choke per K9YC at the same time. Which may, depending on the physical *>* connections at his feedpoint, have removed the feedline shield as an *>* alternate “radial” in parallel with the increasing but still not full size *>* radial system. *>>* That indicates that his ground characteristics could be well into the *>* “poor” end of the range where ground radial deficiencies are multiplied and *>* emphasized. *>>* His SWR bandwidth narrowed slightly. Leaving a strong possibility that *>* there was an improvement in desired radiated pattern. *>>* There remains the question of every conductor in a 250 foot radius, *>* including a tower? There remains the question of large dielectric masses *>* close by. *>>* 73, Guy K2AV * -- _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Re: Topband: Inverted L improvements - Part 3 (now with data)
I worked 160m for a few years when living in a townhome. The antenna was a trap loaded attic mounted dipole that ran through holes in the ceiling and down the walls to the ground. Had a lot of 160m contest fun with that. Worked all the devices in the house as well until I was able to get enough pounds of ferrite on everything electronic. So having some kind of outdoor antenna with some kind of ground by comparison, you will do just fine. Don't worry about how you rack up to the ideal. Just do the best you can and get on the air! 73/jeff/ac0c alpha-charlie-zero-charlie www.ac0c.com On 23-Jan-19 3:21 PM, Jamie WW3S wrote: Todd, don’t get discouraged and don’t let lot size fool youI'm in a subdivision, 80x180 ft lot, with a 50ft tower, hygain hytower for 75/80m (also works as a second radio antenna), and 2L 40m phased array...my inv l is suspended off the top of the towerI never modeled it, I just know it works.DXCC on 160 with low power.now that I added an amp, I'm up to 140+ worked.the secret on 160 is receiving, which really hampers me.forgot the modeling for a minute, did you try the reverse beacon thing I mentioned a few days ago.that will tell you if you are getting out or not.btw, my L is 135 ft (at least it was when it started, I lost a few feet due to some weather related issues)..about 50 ft vertical, then the rest mostly horizontal to a tall tree in the woods -Original Message- From: Todd Goins Sent: Wednesday, January 23, 2019 4:09 PM To: topband@contesting.com ; 676a8e87-aec6-9ead-1297-0bdb1f0a7...@gmail.com Subject: Re: Topband: Inverted L improvements - Part 3 (now with data) Both Merv and Guy are correct here. Perhaps this antenna doesn't ever have a chance at being any good due to the suburban area and lot size that I'm constrained by. Within a 250ft radius (huge!) there is as follows: 80m dipole, 40m dipole, 30m dipole, 20m dipole, 15m dipole, 20m yagi, and the original 43' tall T antenna for 160m and its radial system. Also, the house is easily within 250ft. Most certainly the radial systems, although not physically connected to each other, are let's say "mingling". So perhaps this tall wire was doomed from the outset? I was so encouraged that the 43' T worked so well for what it was and the small amount of effort it took to get converted to 160m that maybe a taller version would be substantially better. That's how this saga started. Maybe the real answer after time/effort/money expended and all of your advise is that it isn't going to get any better in my environment? At this point the best path forward may be to just remove the tall wire and reroute all of the new radials (over 2000ft) to the original 43' T's radial plate and with any luck make it play better as a result? Todd - NR7RR Way back some where around the original posting did he not say he had 2 160 antennas up and they are close to each other? a short vertical and this antenna? If so what is the short vertical doing, is it floating or grounded or hooked to the ground system yet, what is its status? Would make all the difference in the world if the short 160 vertical is any where around yet. 73 Merv K9FD * Have to pay attention to everything he is reporting. He added a feedpoint *>* choke per K9YC at the same time. Which may, depending on the physical *>* connections at his feedpoint, have removed the feedline shield as an *>* alternate “radial” in parallel with the increasing but still not full size *>* radial system. *>>* That indicates that his ground characteristics could be well into the *>* “poor” end of the range where ground radial deficiencies are multiplied and *>* emphasized. *>>* His SWR bandwidth narrowed slightly. Leaving a strong possibility that *>* there was an improvement in desired radiated pattern. *>>* There remains the question of every conductor in a 250 foot radius, *>* including a tower? There remains the question of large dielectric masses *>* close by. *>>* 73, Guy K2AV * -- _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector --- This email has been checked for viruses by AVG. https://www.avg.com _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Re: Topband: Inverted L improvements - Part 3 (now with data)
Spooks! Haunted soil! ;-) That's probably not the problem. As I mentioned privately, I think uploading some more photos to a free file-sharing service website *and sharing those links here* would help us all to help you solve this. Since photo attachments to the Topband Reflector are not possible, can anyone recommend a good file sharing website that Todd (and others) could use? 73, Mike www.w0btu.com On Wed, Jan 23, 2019, 2:48 PM Todd Goins wrote: > Regarding the choke construction and implementation. Mike and I have had an > offline exchange, with pictures, and I think we have agreed that the choke > has been constructed properly per the newest K9YC specifications using a > 2.4" Type 31 Fair-Rite toroid and 18 turns of RG400. > > Also, the 150' long coax feedline has never been attached while taking any > measurements. At least not any reported here. All of the recent data (taken > with the RigExpert analyzer) I've put in tables in postings has been while > being connected to the output of a choke. The feedline was not part of the > equation. The coax stubs coming off of the choke are only a couple of > inches long on each end. The body of the RigExpert is plastic and it > doesn't seem to matter whether or not I'm holding it but I do take the > "official" measurements with it sitting on a towel on the ground. I did > also take measurements with a 4' coax jumper between the choke output and > the analyzer just to get the analyzer clear of the radial attachment area. > This made no appreciable difference in the measured values. > > At this point the "antenna erected over haunted burial ground" theory is > sounding more and more plausible. > > Hope to catch lots of you guys, hey and maybe some DX too, on the 160 > contest this weekend. > > 73, > Todd - NR7RR > _ > Searchable Archives: http://www.contesting.com/_topband - Topband > Reflector > _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Re: Topband: Inverted L improvements - Part 3 (now with data)
Todd, don’t get discouraged and don’t let lot size fool youI'm in a subdivision, 80x180 ft lot, with a 50ft tower, hygain hytower for 75/80m (also works as a second radio antenna), and 2L 40m phased array...my inv l is suspended off the top of the towerI never modeled it, I just know it works.DXCC on 160 with low power.now that I added an amp, I'm up to 140+ worked.the secret on 160 is receiving, which really hampers me.forgot the modeling for a minute, did you try the reverse beacon thing I mentioned a few days ago.that will tell you if you are getting out or not.btw, my L is 135 ft (at least it was when it started, I lost a few feet due to some weather related issues)..about 50 ft vertical, then the rest mostly horizontal to a tall tree in the woods -Original Message- From: Todd Goins Sent: Wednesday, January 23, 2019 4:09 PM To: topband@contesting.com ; 676a8e87-aec6-9ead-1297-0bdb1f0a7...@gmail.com Subject: Re: Topband: Inverted L improvements - Part 3 (now with data) Both Merv and Guy are correct here. Perhaps this antenna doesn't ever have a chance at being any good due to the suburban area and lot size that I'm constrained by. Within a 250ft radius (huge!) there is as follows: 80m dipole, 40m dipole, 30m dipole, 20m dipole, 15m dipole, 20m yagi, and the original 43' tall T antenna for 160m and its radial system. Also, the house is easily within 250ft. Most certainly the radial systems, although not physically connected to each other, are let's say "mingling". So perhaps this tall wire was doomed from the outset? I was so encouraged that the 43' T worked so well for what it was and the small amount of effort it took to get converted to 160m that maybe a taller version would be substantially better. That's how this saga started. Maybe the real answer after time/effort/money expended and all of your advise is that it isn't going to get any better in my environment? At this point the best path forward may be to just remove the tall wire and reroute all of the new radials (over 2000ft) to the original 43' T's radial plate and with any luck make it play better as a result? Todd - NR7RR Way back some where around the original posting did he not say he had 2 160 antennas up and they are close to each other? a short vertical and this antenna? If so what is the short vertical doing, is it floating or grounded or hooked to the ground system yet, what is its status? Would make all the difference in the world if the short 160 vertical is any where around yet. 73 Merv K9FD * Have to pay attention to everything he is reporting. He added a feedpoint *>* choke per K9YC at the same time. Which may, depending on the physical *>* connections at his feedpoint, have removed the feedline shield as an *>* alternate “radial” in parallel with the increasing but still not full size *>* radial system. *>>* That indicates that his ground characteristics could be well into the *>* “poor” end of the range where ground radial deficiencies are multiplied and *>* emphasized. *>>* His SWR bandwidth narrowed slightly. Leaving a strong possibility that *>* there was an improvement in desired radiated pattern. *>>* There remains the question of every conductor in a 250 foot radius, *>* including a tower? There remains the question of large dielectric masses *>* close by. *>>* 73, Guy K2AV * -- _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector --- This email has been checked for viruses by AVG. https://www.avg.com _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Re: Topband: Inverted L improvements - Part 3 (now with data)
Both Merv and Guy are correct here. Perhaps this antenna doesn't ever have a chance at being any good due to the suburban area and lot size that I'm constrained by. Within a 250ft radius (huge!) there is as follows: 80m dipole, 40m dipole, 30m dipole, 20m dipole, 15m dipole, 20m yagi, and the original 43' tall T antenna for 160m and its radial system. Also, the house is easily within 250ft. Most certainly the radial systems, although not physically connected to each other, are let's say "mingling". So perhaps this tall wire was doomed from the outset? I was so encouraged that the 43' T worked so well for what it was and the small amount of effort it took to get converted to 160m that maybe a taller version would be substantially better. That's how this saga started. Maybe the real answer after time/effort/money expended and all of your advise is that it isn't going to get any better in my environment? At this point the best path forward may be to just remove the tall wire and reroute all of the new radials (over 2000ft) to the original 43' T's radial plate and with any luck make it play better as a result? Todd - NR7RR >Way back some where around the original posting did he not say he had >2 160 antennas up and they are close to each other? a short vertical and >this antenna? If so what is the short vertical doing, is it floating or >grounded or hooked to the ground system yet, what is its status? >Would make all the difference in the world if the short 160 vertical is >any where around yet. > >73 Merv K9FD >* Have to pay attention to everything he is reporting. He added a feedpoint *>* choke per K9YC at the same time. Which may, depending on the physical *>* connections at his feedpoint, have removed the feedline shield as an *>* alternate “radial” in parallel with the increasing but still not full size *>* radial system. *>>* That indicates that his ground characteristics could be well into the *>* “poor” end of the range where ground radial deficiencies are multiplied and *>* emphasized. *>>* His SWR bandwidth narrowed slightly. Leaving a strong possibility that *>* there was an improvement in desired radiated pattern. *>>* There remains the question of every conductor in a 250 foot radius, *>* including a tower? There remains the question of large dielectric masses *>* close by. *>>* 73, Guy K2AV * -- _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Re: Topband: Inverted L improvements - Part 3 (now with data)
Regarding the choke construction and implementation. Mike and I have had an offline exchange, with pictures, and I think we have agreed that the choke has been constructed properly per the newest K9YC specifications using a 2.4" Type 31 Fair-Rite toroid and 18 turns of RG400. Also, the 150' long coax feedline has never been attached while taking any measurements. At least not any reported here. All of the recent data (taken with the RigExpert analyzer) I've put in tables in postings has been while being connected to the output of a choke. The feedline was not part of the equation. The coax stubs coming off of the choke are only a couple of inches long on each end. The body of the RigExpert is plastic and it doesn't seem to matter whether or not I'm holding it but I do take the "official" measurements with it sitting on a towel on the ground. I did also take measurements with a 4' coax jumper between the choke output and the analyzer just to get the analyzer clear of the radial attachment area. This made no appreciable difference in the measured values. At this point the "antenna erected over haunted burial ground" theory is sounding more and more plausible. Hope to catch lots of you guys, hey and maybe some DX too, on the 160 contest this weekend. 73, Todd - NR7RR _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Re: Topband: Inverted L improvements - Part 3 (now with data)
Your "apparent" and mine are different because it isn't apparent to me that I advocated that. I offered a possible explanation to what Todd is observing and provided the title of a reference source where he could explore it more fully. I mentioned what I am using and my rational for doing so. Wes N7WS On 1/22/2019 3:12 PM, Mike Smith VE9AA wrote: So, now we're (apparently) recommending he cut back his already minimal radial field..uhhh, really Wes? _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Re: Topband: Inverted L improvements - Part 3 (now with data)
It's possible that the K9YC choke was improperly wound, per my forwarded message from Jim here yesterday. Here is K9YC's updated info on choke baluns. http://k9yc.com/2018Cookbook.pdf 73, Mike www.w0btu.com On Wed, Jan 23, 2019, 1:05 AM Guy Olinger K2AV wrote: > ... > He inserted a K9YC design choke at feedpoint and his R went up, indicating > that the earlier measurement was lowered by something shunting down the > true R of the radials. > ... _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Re: Topband: Inverted L improvements - Part 3 (now with data)
What is missing from that discussion about a maximized use of a given investment, is whether that investment however well maximized, is in fact adequate for the particular ground characteristics and circumstances. Four rotten eggs will deliver a rotten omelette no matter what you mix in or how neatly it’s served up. In seriously poor ground, the total copper in the radials needs to be enough for full size, dense and uniform all around. A maximized inadequate is still inadequate. Sparse, undersized, or irregular ground radials do not do it for poor ground. His results with shorter radials suspiciously point to poor ground or perhaps a local loss issue not yet identified. He inserted a K9YC design choke at feedpoint and his R went up, indicating that the earlier measurement was lowered by something shunting down the true R of the radials. 73, Guy K2AV On Tue, Jan 22, 2019 at 10:31 PM Chortek, Robert L. < robert.chor...@berliner.com> wrote: > Exactly! > > Sent from my iPhone > > > On Jan 22, 2019, at 7:25 PM, Grant Saviers wrote: > > > > Al Christman K3LC thoroughly sliced and diced the tradeoffs of number vs > length for given total wire investment is his Mar/Apr 2004 NCJ paper. > > > > N6LF also has a lot to say. > > > > Grant KZ1W > > > >> On 1/22/2019 16:11 PM, Chortek, Robert L. wrote: > >> “Wes cut his radial length to match the vertical L section height (see > N6LF > >>> reference). He didn't reduce the number of radials.” > >> I didn’t think it was the “shortening” OF the length of the radials > that would improve performance e.g. going from 10 125’ radials to 10 55’ > radials (in the case of a 55’ vertical); rather, it was the fact that 10x > 125’ of wire could be better employed to increase the number of radials, > albeit resulting in shorter radials, that decreases the ground loss (since > most is nearer the base of the vertical). If I’m correct, then shortening > a given number of radials should decrease loss or improve performance > >> 73, > >> Bob AA6VB > >> _ > >> Searchable Archives: http://www.contesting.com/_topband - Topband > Reflector > _ > Searchable Archives: http://www.contesting.com/_topband - Topband > Reflector > -- Sent via Gmail Mobile on my iPhone _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Re: Topband: Inverted L improvements - Part 3 (now with data)
Exactly! Sent from my iPhone > On Jan 22, 2019, at 7:25 PM, Grant Saviers wrote: > > Al Christman K3LC thoroughly sliced and diced the tradeoffs of number vs > length for given total wire investment is his Mar/Apr 2004 NCJ paper. > > N6LF also has a lot to say. > > Grant KZ1W > >> On 1/22/2019 16:11 PM, Chortek, Robert L. wrote: >> “Wes cut his radial length to match the vertical L section height (see N6LF >>> reference). He didn't reduce the number of radials.” >> I didn’t think it was the “shortening” OF the length of the radials that >> would improve performance e.g. going from 10 125’ radials to 10 55’ radials >> (in the case of a 55’ vertical); rather, it was the fact that 10x 125’ of >> wire could be better employed to increase the number of radials, albeit >> resulting in shorter radials, that decreases the ground loss (since most is >> nearer the base of the vertical). If I’m correct, then shortening a given >> number of radials should decrease loss or improve performance >> 73, >> Bob AA6VB >> _ >> Searchable Archives: http://www.contesting.com/_topband - Topband Reflector _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Re: Topband: Inverted L improvements - Part 3 (now with data)
Al Christman K3LC thoroughly sliced and diced the tradeoffs of number vs length for given total wire investment is his Mar/Apr 2004 NCJ paper. N6LF also has a lot to say. Grant KZ1W On 1/22/2019 16:11 PM, Chortek, Robert L. wrote: “Wes cut his radial length to match the vertical L section height (see N6LF reference). He didn't reduce the number of radials.” I didn’t think it was the “shortening” OF the length of the radials that would improve performance e.g. going from 10 125’ radials to 10 55’ radials (in the case of a 55’ vertical); rather, it was the fact that 10x 125’ of wire could be better employed to increase the number of radials, albeit resulting in shorter radials, that decreases the ground loss (since most is nearer the base of the vertical). If I’m correct, then shortening a given number of radials should decrease loss or improve performance 73, Bob AA6VB _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Re: Topband: Inverted L improvements - Part 3 (now with data)
Meant to say “should not decrease loss ...” Sorry! Bob AA6VB Sent from my iPhone > On Jan 22, 2019, at 4:11 PM, Chortek, Robert L. > wrote: > > “Wes cut his radial length to match the vertical L section height (see N6LF >> reference). He didn't reduce the number of radials.” > > I didn’t think it was the “shortening” OF the length of the radials that > would improve performance e.g. going from 10 125’ radials to 10 55’ radials > (in the case of a 55’ vertical); rather, it was the fact that 10x 125’ of > wire could be better employed to increase the number of radials, albeit > resulting in shorter radials, that decreases the ground loss (since most is > nearer the base of the vertical). If I’m correct, then shortening a given > number of radials should decrease loss or improve performance > > 73, > > Bob AA6VB _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Re: Topband: Inverted L improvements - Part 3 (now with data)
Way back some where around the original posting did he not say he had 2 160 antennas up and they are close to each other? a short vertical and this antenna? If so what is the short vertical doing, is it floating or grounded or hooked to the ground system yet, what is its status? Would make all the difference in the world if the short 160 vertical is any where around yet. 73 Merv K9FD Have to pay attention to everything he is reporting. He added a feedpoint choke per K9YC at the same time. Which may, depending on the physical connections at his feedpoint, have removed the feedline shield as an alternate “radial” in parallel with the increasing but still not full size radial system. That indicates that his ground characteristics could be well into the “poor” end of the range where ground radial deficiencies are multiplied and emphasized. His SWR bandwidth narrowed slightly. Leaving a strong possibility that there was an improvement in desired radiated pattern. There remains the question of every conductor in a 250 foot radius, including a tower? There remains the question of large dielectric masses close by. 73, Guy K2AV _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Re: Topband: Inverted L improvements - Part 3 (now with data)
“Wes cut his radial length to match the vertical L section height (see N6LF > reference). He didn't reduce the number of radials.” I didn’t think it was the “shortening” OF the length of the radials that would improve performance e.g. going from 10 125’ radials to 10 55’ radials (in the case of a 55’ vertical); rather, it was the fact that 10x 125’ of wire could be better employed to increase the number of radials, albeit resulting in shorter radials, that decreases the ground loss (since most is nearer the base of the vertical). If I’m correct, then shortening a given number of radials should decrease loss or improve performance 73, Bob AA6VB _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Re: Topband: Inverted L improvements - Part 3 (now with data)
>So, now we're (apparently) recommending he cut back his already minimal radial field..uhhh, really Wes? I agree with Wes' assessment -- as well as him questioning why Rr would increase with an increased number of radials. If Rr is changing significantly with the increase, then something else is perturbing the measurement. Wes cut his radial length to match the vertical L section height (see N6LF reference). He didn't reduce the number of radials. Paul, W9AC _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Re: Topband: Inverted L improvements - Part 3 (now with data)
So, now we're (apparently) recommending he cut back his already minimal radial field..uhhh, really Wes? =-Mike VE9AA I started this message a day or so ago. Others have commented since with some similar thoughts, nevertheless, here is my take. Todd you're going the wrong direction. The feed point resistance should be going down. A 1/4 wave wire vertical should have a radiation resistance(Rr) of around 35 ohm. Ignoring conductor loss, over a perfect (zero ohm) ground, the feed point resistance is also ~35 ohm. The Rr of a shortened, top loaded vertical (inverted-L) will be lower than that, the shorter, the lower. Ground loss resistance (Rg) that appears in series with the Rr increases the feed point resistance to Rr + Rg, assuming resonance. Rg also lowers Q. Since your total feed point resistance is increasing, as is BW, you must have increased Rg. Although this seems counter-intuitive, experiments have shown that, on or in, the ground radials can be too long. See: "Vertical antenna ground system experiment No. 4" by N6LF. For my inverted L, I cut my insulated-on-the-ground radials to 55' because 1) that's the height of the vertical part of the L; 2) it gives me 9 radials with no waste from a 500' roll of wire and 3) that's the longest length I can use and still maintain symmetry. I recently measured the Z of one of these against the rest of the ground system with a network analyzer and by serendipity found it resonant at ~1.9 MHz. At the moment I have only 12 radials, although I plan more (see my QRZ page to see why I haven't rushed into this). Around resonance, a Smith chart display of a model of the antenna feed point Z overlays nearly identically the measured Z, if I add 13 ohm simulated ground resistance to the model. That is the apparent ground loss. Wes N7WS Mike, Coreen & Corey Keswick Ridge, NB _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Re: Topband: Inverted L improvements - Part 3 (now with data)
Have to pay attention to everything he is reporting. He added a feedpoint choke per K9YC at the same time. Which may, depending on the physical connections at his feedpoint, have removed the feedline shield as an alternate “radial” in parallel with the increasing but still not full size radial system. That indicates that his ground characteristics could be well into the “poor” end of the range where ground radial deficiencies are multiplied and emphasized. His SWR bandwidth narrowed slightly. Leaving a strong possibility that there was an improvement in desired radiated pattern. There remains the question of every conductor in a 250 foot radius, including a tower? There remains the question of large dielectric masses close by. 73, Guy K2AV -- Sent via Gmail Mobile on my iPhone _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Re: Topband: Inverted L improvements - Part 3 (now with data)
On 1/22/2019 8:03 AM, Bruce wrote: You maybe confusing "Radiation Resistance" with "Feed point Resistance". It often will lower "Feed point Resistance", but raise "radiation Resistance". Really? Why? Wes N7WS _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Re: Topband: Inverted L improvements - Part 3 (now with data)
I started this message a day or so ago. Others have commented since with some similar thoughts, nevertheless, here is my take. Todd you're going the wrong direction. The feed point resistance should be going down. A 1/4 wave wire vertical should have a radiation resistance(Rr) of around 35 ohm. Ignoring conductor loss, over a perfect (zero ohm) ground, the feed point resistance is also ~35 ohm. The Rr of a shortened, top loaded vertical (inverted-L) will be lower than that, the shorter, the lower. Ground loss resistance (Rg) that appears in series with the Rr increases the feed point resistance to Rr + Rg, assuming resonance. Rg also lowers Q. Since your total feed point resistance is increasing, as is BW, you must have increased Rg. Although this seems counter-intuitive, experiments have shown that, on or in, the ground radials can be too long. See: "Vertical antenna ground system experiment No. 4" by N6LF. For my inverted L, I cut my insulated-on-the-ground radials to 55' because 1) that's the height of the vertical part of the L; 2) it gives me 9 radials with no waste from a 500' roll of wire and 3) that's the longest length I can use and still maintain symmetry. I recently measured the Z of one of these against the rest of the ground system with a network analyzer and by serendipity found it resonant at ~1.9 MHz. At the moment I have only 12 radials, although I plan more (see my QRZ page to see why I haven't rushed into this). Around resonance, a Smith chart display of a model of the antenna feed point Z overlays nearly identically the measured Z, if I add 13 ohm simulated ground resistance to the model. That is the apparent ground loss. Wes N7WS On 1/21/2019 6:45 PM, Todd Goins wrote: Hello, Per many people's recommendations I added 800ft of radials today. That is 8 x 100ft each. It made a difference on the analyzer which I'll summarize below. It was dark when I finished but here are a few data points. I think it is better. The wide SWR curve still bothers me but the resistance is coming up. This is also using the new K9YC cookbook choke with 18 turns of RG400 around a 2.4" type 31 toroid. The values are Freq, SWR, R, X, Z 1810 1.43 42.0 -14.5 44.5 1820 1.31 43.2 -10.7 44.5 1830 1.21 44.1 -6.7 44.7 1840 1.13 45.0 -2.5 45.1 1850 1.10 45.9 1.7 45.9 1860 1.14 47.0 5.7 47.3 1870 1.23 48.0 10.1 49.1 1880 1.34 49.1 14.7 51.2 Any thoughts? The 160 CW contest is only 4 days away, I don't have a lot more time to make changes but I could run a "few" more radials... 73, Todd - NR7RR _ Searchable Archives:http://www.contesting.com/_topband - Topband Reflector _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Re: Topband: Inverted L improvements - Part 3 (now with data)
Indeed, that is what I meant to say. On Tue, Jan 22, 2019 at 10:03 AM Bruce wrote: > You maybe confusing "Radiation Resistance" with "Feed point Resistance". > It often will lower "Feed point Resistance", but raise "radiation > Resistance". 73 Bruce > > On 1/22/2019 9:45 AM, Peter Bertini wrote: > > I would think adding radials would lower the Radiation resistance. Also, > > the SWR curve should narrow as ground losses are reduced; since the > effect > > of ground loss resistance swamping the results lessens. > > > > At some point I suggest, as others, that you get on for the contest and > see > > what you can do. If you can run a bit of power, it will help. Receiving > > is indeed the tough nut to crack on 160 Meters. > > > > Elevated radials may be worth a shot. I think Mike uses two with good > > results. I went to a K2AV FCP and it works good enough for my needs. Even > > with a K9AY loop system receiving is still my weak point. > > > > Get on for the contests and have some fun. > > > > Pete > > _ > > Searchable Archives: http://www.contesting.com/_topband - Topband > Reflector > > > _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Re: Topband: Inverted L improvements - Part 3 (now with data)
Todd, The resistive component should be going down with more radials, not up. Maybe you are not measuring it the right way, or something in the radial system could be resonant (which may be a good thing). Normally, with these antennas, lower R is better (less loss). I have just measured a top loaded 57 foot tall vertical that stands in salt-water, which is an almost perfect ground. The feed point R is 8.5 Ohms. (Using an AIM-55 analyzer.) Anyway, does your antenna get out? That is the ultimate test. George, AA7JV/C6AGU On Mon, 21 Jan 2019 17:45:52 -0800 Todd Goins wrote: Hello, Per many people's recommendations I added 800ft of radials today. That is 8 x 100ft each. It made a difference on the analyzer which I'll summarize below. It was dark when I finished but here are a few data points. I think it is better. The wide SWR curve still bothers me but the resistance is coming up. This is also using the new K9YC cookbook choke with 18 turns of RG400 around a 2.4" type 31 toroid. The values are Freq, SWR, R, X, Z 1810 1.43 42.0 -14.5 44.5 1820 1.31 43.2 -10.7 44.5 1830 1.21 44.1 -6.7 44.7 1840 1.13 45.0 -2.5 45.1 1850 1.10 45.9 1.7 45.9 1860 1.14 47.0 5.7 47.3 1870 1.23 48.0 10.1 49.1 1880 1.34 49.1 14.7 51.2 Any thoughts? The 160 CW contest is only 4 days away, I don't have a lot more time to make changes but I could run a "few" more radials... 73, Todd - NR7RR _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Re: Topband: Inverted L improvements - Part 3 (now with data)
>"I would think adding radials would lower the Radiation resistance. Also, the SWR curve should narrow as ground losses are reduced; since the effect of ground loss resistance swamping the results lessens." The base resistance, not the radiation resistance is lowered by adding in radials. At resonance, the antenna's feed-point equivalent circuit is two resistors in series: Rr for the radiated component, and Rg for the loss component. By lowering Rg, efficiency increases and feed-point resistance is reduced when additional radials are added. Paul, W9AC _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Re: Topband: Inverted L improvements - Part 3 (now with data)
You maybe confusing "Radiation Resistance" with "Feed point Resistance". It often will lower "Feed point Resistance", but raise "radiation Resistance". 73 Bruce On 1/22/2019 9:45 AM, Peter Bertini wrote: I would think adding radials would lower the Radiation resistance. Also, the SWR curve should narrow as ground losses are reduced; since the effect of ground loss resistance swamping the results lessens. At some point I suggest, as others, that you get on for the contest and see what you can do. If you can run a bit of power, it will help. Receiving is indeed the tough nut to crack on 160 Meters. Elevated radials may be worth a shot. I think Mike uses two with good results. I went to a K2AV FCP and it works good enough for my needs. Even with a K9AY loop system receiving is still my weak point. Get on for the contests and have some fun. Pete _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Re: Topband: Inverted L improvements - Part 3 (now with data)
I would think adding radials would lower the Radiation resistance. Also, the SWR curve should narrow as ground losses are reduced; since the effect of ground loss resistance swamping the results lessens. At some point I suggest, as others, that you get on for the contest and see what you can do. If you can run a bit of power, it will help. Receiving is indeed the tough nut to crack on 160 Meters. Elevated radials may be worth a shot. I think Mike uses two with good results. I went to a K2AV FCP and it works good enough for my needs. Even with a K9AY loop system receiving is still my weak point. Get on for the contests and have some fun. Pete _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Re: Topband: Inverted L improvements - Part 3 (now with data)
Man, that seems awfully broad! Somewhere, you have losses, my friend. You ARE measuring directly at the feedpoint, aren't you? And with the antenna analyzer FLOATING (not touching you, the earth, or anything else)? FWIW, the K9YC choke I used was about 6 turns of RG-6 wound through 4 or 5 *stacked* 2.4" Type 31 Fair-rite cores, *directly at the feedpoint*. Photos linked to partway down the page at http://www.w0btu.com/160_meters.html. As you'll see, I'm an elevated radials man. Saves a lot of $ in radials lying directly on the earth. Also, please see w0btu.com/Optimum_number_of_ground_radials_vs_radial_length.html 73, Mike www.w0btu.com On Mon, Jan 21, 2019, 7:46 PM Todd Goins wrote: > Hello, > > Per many people's recommendations I added 800ft of radials today. That is 8 > x 100ft each. It made a difference on the analyzer which I'll summarize > below. It was dark when I finished but here are a few data points. I think > it is better. The wide SWR curve still bothers me but the resistance is > coming up. > > This is also using the new K9YC cookbook choke with 18 turns of RG400 > around a 2.4" type 31 toroid. > > The values are Freq, SWR, R, X, Z > > 1810 1.43 42.0 -14.5 44.5 > 1820 1.31 43.2 -10.7 44.5 > 1830 1.21 44.1 -6.7 44.7 > 1840 1.13 45.0 -2.5 45.1 > 1850 1.10 45.9 1.7 45.9 > 1860 1.14 47.0 5.7 47.3 > 1870 1.23 48.0 10.1 49.1 > 1880 1.34 49.1 14.7 51.2 > > Any thoughts? The 160 CW contest is only 4 days away, I don't have a lot > more time to make changes but I could run a "few" more radials... > > 73, > Todd - NR7RR > > _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Re: Topband: Inverted L improvements - Part 3 (now with data)
Todd, get on the contest and rock and roll. I don't know of anyone on 160m who has not given their antennas an iterative workout over time. Bet you will do just fine. RX is the tougher nut anyway. Good luck 73/jeff/ac0c alpha-charlie-zero-charlie www.ac0c.com On 21-Jan-19 7:47 PM, Jamie WW3S wrote: did you try transmitting with it, and see if any skimmers pick you up? just try sending test de urcall and check the RBN network, see how you are getting out -Original Message- From: Todd Goins Sent: Monday, January 21, 2019 8:45 PM To: topband@contesting.com Subject: Re: Topband: Inverted L improvements - Part 3 (now with data) Hello, Per many people's recommendations I added 800ft of radials today. That is 8 x 100ft each. It made a difference on the analyzer which I'll summarize below. It was dark when I finished but here are a few data points. I think it is better. The wide SWR curve still bothers me but the resistance is coming up. This is also using the new K9YC cookbook choke with 18 turns of RG400 around a 2.4" type 31 toroid. The values are Freq, SWR, R, X, Z 1810 1.43 42.0 -14.5 44.5 1820 1.31 43.2 -10.7 44.5 1830 1.21 44.1 -6.7 44.7 1840 1.13 45.0 -2.5 45.1 1850 1.10 45.9 1.7 45.9 1860 1.14 47.0 5.7 47.3 1870 1.23 48.0 10.1 49.1 1880 1.34 49.1 14.7 51.2 Any thoughts? The 160 CW contest is only 4 days away, I don't have a lot more time to make changes but I could run a "few" more radials... 73, Todd - NR7RR _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector --- This email has been checked for viruses by AVG. https://www.avg.com _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Re: Topband: Inverted L improvements - Part 3 (now with data)
did you try transmitting with it, and see if any skimmers pick you up? just try sending test de urcall and check the RBN network, see how you are getting out -Original Message- From: Todd Goins Sent: Monday, January 21, 2019 8:45 PM To: topband@contesting.com Subject: Re: Topband: Inverted L improvements - Part 3 (now with data) Hello, Per many people's recommendations I added 800ft of radials today. That is 8 x 100ft each. It made a difference on the analyzer which I'll summarize below. It was dark when I finished but here are a few data points. I think it is better. The wide SWR curve still bothers me but the resistance is coming up. This is also using the new K9YC cookbook choke with 18 turns of RG400 around a 2.4" type 31 toroid. The values are Freq, SWR, R, X, Z 1810 1.43 42.0 -14.5 44.5 1820 1.31 43.2 -10.7 44.5 1830 1.21 44.1 -6.7 44.7 1840 1.13 45.0 -2.5 45.1 1850 1.10 45.9 1.7 45.9 1860 1.14 47.0 5.7 47.3 1870 1.23 48.0 10.1 49.1 1880 1.34 49.1 14.7 51.2 Any thoughts? The 160 CW contest is only 4 days away, I don't have a lot more time to make changes but I could run a "few" more radials... 73, Todd - NR7RR _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector --- This email has been checked for viruses by AVG. https://www.avg.com _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Re: Topband: Inverted L improvements - Part 3 (now with data)
Hello, Per many people's recommendations I added 800ft of radials today. That is 8 x 100ft each. It made a difference on the analyzer which I'll summarize below. It was dark when I finished but here are a few data points. I think it is better. The wide SWR curve still bothers me but the resistance is coming up. This is also using the new K9YC cookbook choke with 18 turns of RG400 around a 2.4" type 31 toroid. The values are Freq, SWR, R, X, Z 1810 1.43 42.0 -14.5 44.5 1820 1.31 43.2 -10.7 44.5 1830 1.21 44.1 -6.7 44.7 1840 1.13 45.0 -2.5 45.1 1850 1.10 45.9 1.7 45.9 1860 1.14 47.0 5.7 47.3 1870 1.23 48.0 10.1 49.1 1880 1.34 49.1 14.7 51.2 Any thoughts? The 160 CW contest is only 4 days away, I don't have a lot more time to make changes but I could run a "few" more radials... 73, Todd - NR7RR _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Re: Topband: Inverted L improvements - Part 3 (now with data)
Fred had to laugh. I fear my son (yeah a ham) will put all my stuff on the lawn with a small bucket for any money they feel it is worth. Use iT! de KG9H > On Jan 21, 2019, at 8:44 AM, wrote: > > Thank You Guy for taking the time for all great the info. > > I have several pieces of RG400 none are long enough. > I was an airfield electrician for CVG airport. > Got some out of planes and some from the FAA I would demo stuff for them. > > I will be looking for some RG400 on the web to make a few proper chokes > > I guess I don't know as much abt chokes as I thought. > I figured any old wire would do. > I will reread K9YC papers on the subject. > > ''You can put your lifetime stash of RG400 in your will, and leave it to a > younger local ham, who will appreciate it. :>)) > > That made me chuckle..when I die my kids will throw all my stuff in the > trash... ;0 :) > > Love this reflector always learning here. > > Thanks > Fred KB4QZH > > > _ > Searchable Archives: http://www.contesting.com/_topband - Topband Reflector _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Re: Topband: Inverted L improvements - Part 3 (now with data)
Hi, Fred. You said: "Guy K2AV I'm guessing you don't like rg58 because of the center conductor moving outwards??" Nope. :>)) RG58 is not RG400. That's why I don't like RG58. RG400 is what should be used for winding coax on toroids. RG400 is a currently manufactured item. It is INTENDED to handle sharp bends as found in aircraft wiring harnesses (and therefore also handle being wound on toroids). The center conductor is silvered stranded copper, the dielectric is PTFE (Teflon), the shield is TWO dense woven layers of silvered copper braid, and the jacket is PTFE. RG400 is rated to 7 kW. RG400 is Mil Spec. MIL-C-17 27478. Which means that if your house blows up from a gas explosion, the RG400 will still be there working when the fire is put out. Essentially it never ever goes bad or weird unless catastrophically treated, like crushed with a hammer, nailed through, ends submerged in battery acid, or used as a tow rope for something heavy. I have one piece of RG400 that was inappropriately used to arrest the fall of and suspend a linear amp in mid-air. The coax still works, but it looks funny, and it wasn't 50 ohms any more. A Chinese finger trap on the dielectric. The silvered copper conductors in the double shields and stranded copper center conductor will not deteriorate from occasional moist air in the coax and convert it to many small conductors with performance changes, because silver oxide is conductive. The dense silvered copper shield weave, with two layers of shield weave in RG400, makes for extremely good shielding. A lot of RG58 is cr*p shielding, sparse enough to see through, sparse to maximize profit. The PTFE in the jacket and dielectric is a low loss material, will not deteriorate from ultraviolet. PTFE will not gradually shrink or crack by leaching its chemical components. The jacket and dielectric will not melt and ruin a connector when you solder it, or when you forget it's there and put 1500 watts on it. PTFE is a highly robust and predictable material. The PVC jacket formulation on RG58 could be just about anything. People have discovered that jumpers and leftover pieces of RG400 can be sold on eBay. So you can pick up a ten foot piece of RG400 for less than retail. I like the pieces with a male BNC on one end. I hate doing BNC connectors. Brand-new coils of 100' plus can occasionally be had for as little as 1.80 USD per foot, and regularly for 2.30 USD per foot, on eBay. For all intents and purposes, a toroid wound with RG400 is a permanent device, lifetime depending on the toroid instead of the coax. You should buy enough RG400 so RG400 is the small coax that's "laying around" and still good as new to do a project with, even if you bought it 20 years ago. You can put your lifetime stash of RG400 in your will, and leave it to a younger local ham, who will appreciate it. :>)) RG400 is also K9YC's choice in his new http://audiosystemsgroup.com/2018Cookbook.pdf. Check out the monster common mode blocking choke wound with 23 turns of RG400 over a 4" OD, 3" ID, inch thick #31 ferrite toroid. THAT'S a choke. 17K ohms resistive on 160. 73, Guy K2AV On Sun, Jan 20, 2019 at 12:36 PM wrote: > Hello everyone. > > I also trying to improve things here on 160 and other bands. > Going to make a few chokes. > I have wound 8 turns thru 2.4 x2 31 mix but haven't seen any real > improvement. > Trying to get rid of some birdies. > > Guy K2AV I'm guessing you don't like rg58 because of the center conductor > moving outwards?? > > 73 Fred KB4QZH > > > _ > Searchable Archives: http://www.contesting.com/_topband - Topband > Reflector > _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Re: Topband: Inverted L improvements - Part 3 (now with data)
Hi Todd, Have a look at the calculator at https://chemandy.com/calculators/return-loss-and-mismatch-calculator.htm This calculator allows me to compute the SWR for your data points, as if the Z zero of the meter was 32 ohms. This is important because so many excellent antennas exhibit raw feed R between 15 and 35 ohms. This exercise will give me SWR numbers the same as if I had put a 32 ohm to 50 ohm unun in front of your 50 ohm SWR meter. Using the calculator gives a revised and normalized table: 1820 1.61 29.1 -14.3 1840 1.20 31.0 -5.7 1850 1.04 32.0 -1.3 1860 1.12 33.0 3.6 1880 1.49 35.3 13.0 1900 1.95 38 22.9 This allows me to determine matched to 50 ohm line 1.5:1 SWR points at 1825 and 1880 or a 1.5:1 bandwidth of 55 kHz. A good guess would be that the 2:1 bandwidth is nearly all of 1.8 to 1.9 Both are far too broad, indicating considerable RF loss yet to be pin-pointed and remedied. I have a full size inverted L over an FCP, whose feed R at the shack side of the isolation transformer is 30 to 32 ohms. This conveniently allows me to use a Balun Designs 16132 Unun (32 ohms in, 50 ohms out) to match the natural R of the antenna to the 50 ohm feedline to the shack. At the Unun output, my 1.5:1 points are 1807 and 1832 for a 1.5:1 SWR bandwidth of 25 kHz. On the shack side of 82 feet of LDF4-50A 1/2 inch hardline, the 1.5:1 points are 1804 and 1832 for a 1.5:1 SWR bandwidth of 28 kHz at the operating position. Over the last two years, this antenna has been carefully designed/worked over to eliminate loss. Removing the loss will narrow SWR bandwidth. My shack SWR at 1880 is 4.8:1. Switching in secondary matching (ATR30) is necessary to work in the high 1.8's and above 1.9. I would be interested in the RigExpert raw feed numbers without the choke (I have a hard-to-shake dim view of RG58, especially old RG58). It would also be helpful to have the RigExpert model number, and measurements taken at 10 kHz points. Good luck on the project. You have to keep working the problem. 73, Guy K2AV On Fri, Jan 18, 2019 at 8:23 PM Todd Goins wrote: > Hello, > > I borrowed a RigExpert analyzer and was able to take measurements that > folks were asking for without AM station overload. I also built the K9YC > 160m choke (18 turns of RG58 on a type 31 2.4" toroid). That choke is at > the feed point of the vertical. The analyzer was connected directly after > the choke. > > I have a collection of data and typed it into Excel but I can summarize > here. > > The values are Freq, SWR, R, X, Z > > 1810 2.1 > 1820 1.9 29.1 -14.3 32.4 > 1840 1.8 31.0 -5.7 31.5 > 1850 1.7 32.0 -1.3 32.1 > 1860 1.5 33.0 3.6 33.2 > 1880 1.6 35.3 13.0 37.6 > 1900 1.8 38.0 22.9 44.4 > 1920 2.1 > 1940 2.5 > 1960 3.0 > 1990 3.9 > > I still only have the 30 x 42' radials attached but can add about 5 x 100' > more radials (in a non uniform layout) if that might help. > > Fair, bad, really bad, horrible, hopeless? Any advice is appreciated. > > 73, > Todd - NR7RR > _ > Searchable Archives: http://www.contesting.com/_topband - Topband > Reflector > _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Re: Topband: Inverted L improvements - Part 3 (now with data)
Hello, I borrowed a RigExpert analyzer and was able to take measurements that folks were asking for without AM station overload. I also built the K9YC 160m choke (18 turns of RG58 on a type 31 2.4" toroid). That choke is at the feed point of the vertical. The analyzer was connected directly after the choke. I have a collection of data and typed it into Excel but I can summarize here. The values are Freq, SWR, R, X, Z 1810 2.1 1820 1.9 29.1 -14.3 32.4 1840 1.8 31.0 -5.7 31.5 1850 1.7 32.0 -1.3 32.1 1860 1.5 33.0 3.6 33.2 1880 1.6 35.3 13.0 37.6 1900 1.8 38.0 22.9 44.4 1920 2.1 1940 2.5 1960 3.0 1990 3.9 I still only have the 30 x 42' radials attached but can add about 5 x 100' more radials (in a non uniform layout) if that might help. Fair, bad, really bad, horrible, hopeless? Any advice is appreciated. 73, Todd - NR7RR _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
