Topband: What goes over the FCP?
I took my poorly-erected FCP down a couple of years ago to move it to a new QTH. Time to put it back up. What should I put over it? I have my choice of a standard Inverted-L or a 3-wire T-top The T-top has 3 wires, about 55' long, separated 1' by 1/2" fiberglass spreaders. The vertical portion of either antenna would be about 80'. There will be fir trees involved, but I'll keep the antenna as far away from them as I can. Suggestions gratefully received. VE7XF _ 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: Topband]Updated K9YC common-mode choke PDF now available
I have been using RG400 to make jumpers for years. It is a nice easy to work with coax that has excellent shielding. RG400 is available surplus for much less than $5/ft. John KK9A W8ZR wrote: Very interesting, Jim. I wasn't familiar with RG-400, but I've used RG-142B for years. I compared the specs and found they're virtually identical, the only significant difference being that RG-400 has a stranded center conductor, while RG-142B has a solid steel (silver-plated) center conductor. They both have a 1 inch minimum bending radius (for repeated bending), but I imagine the RG-400 Is slightly more flexible and the RG142B is slightly stronger. At GHz frequencies, the RG142B has slightly lower loss. They both have excellent high temperature properties. If you buy it new from a distributor, either will cost about $5 a foot. 73, Jim w8zr _ 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: Updated K9YC common-mode choke PDF now available
Very interesting, Jim. I wasn't familiar with RG-400, but I've used RG-142B for years. I compared the specs and found they're virtually identical, the only significant difference being that RG-400 has a stranded center conductor, while RG-142B has a solid steel (silver-plated) center conductor. They both have a 1 inch minimum bending radius (for repeated bending), but I imagine the RG-400 Is slightly more flexible and the RG142B is slightly stronger. At GHz frequencies, the RG142B has slightly lower loss. They both have excellent high temperature properties. If you buy it new from a distributor, either will cost about $5 a foot. 73, Jim w8zr Sent from my iPad > On Jan 22, 2019, at 6:42 PM, Mike Waters wrote: > > -- Forwarded message - > From: Jim Brown > Date: Mon, Jan 21, 2019, 11:36 PM > Subject: Re: Topband: Inverted L improvements - Part 3 (now with data) > To: Mike Waters > > After nearly a year of work, I published a new "cookbook" last month. > For reasons that are detailed in the accompanying text, I no longer > recommend coax wound through multiple cores. > > The short answer for "why not?" is that it's simply not practical to wind > chokes that way and get anything close to the same result every time -- > turns must go through the core in the same order, a scrambled turn cancels > a turn, turn diameter matters a lot, and so on. > > The new cookbook uses RG400, 12-2 Teflon/silver pairs, or 12/2 THHN or NM > pairs, all tightly wound around a single core. There are recommendations > for chokes in series to increase power handling. There is also data for the > new 4-in o.d. supersized toroids, which are great for 160M. > k9yc.com/2018Cookbook.pdf > > 73, Jim K9YC > _ > Searchable Archives: http://www.contesting.com/_topband - Topband Reflector _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Re: Topband: QRG on 160 in North and South America
Hello Top Band enthusiast. With regards to this forbidden dx frequency list and other beacon list, they seem to be very outdated, as there has NOT been any Digi signal on 1818,0 in ZL or sometimes referred to as a GPS correction signal on 1818.0 in ZL for many years. We do have, in the Pacific and Southern Ocean the odd fishing beacon, which each year seem to on different frequencies and so references to a list from previous years, I think is never accurate or useful. As far as I can hear, we have NO bad frequencies down here, except for FT8 around 1840.0 + or -. Our biggest problem is QRN from tropical areas in VK and Pacific/Indian Ocean and other lightning storms and this summer I think it has been much worse than previous years. Based on this weeks weather forecast, I don't think we will have much fun in VK land in this years Top Band contest. Cheers, from Ron vk3io. On 22-Jan-19 8:12 AM, Petr Ourednik wrote: Rune check this link also http://160mband.blogspot.com/2018/02/the-forbidden-dx-frequencies-table-on.html Petr OK1RP On Mon, Jan 21, 2019, at 10:01 PM, Wes wrote: I have heard them on 1829.4 here in Arizona. Wes N7WS On 1/21/2019 10:41 AM, Rune Øye wrote: All, We are preparing our WEB page for 7P8 In March this year. I am aware about fish beacon and bad QRG`s seen from Northern EU, JA`s basically from 1820 to 1825. What frequency should be avoided in North and South America?. License received, waiting final confirmation from our host regards to the antenna "farm". 73 Rune LA7THA _ 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
