Re: Topband: Balun Question
Hi, Gary, That does sound like a nice location! Well, I worked over 300 countries with antennas supported by trees, before I finally got a little 40' tower to support my home-brew 5-band quad. In trees, I had 40 and 30m vertical dipoles, 40m vertical yagis - some reversible, -full-size 80m GP, and inverted Ls for 160. I worked some good DXpedition stuff like 3Y0 etc. through ferocious pile-ups - sometimes on "first call"! So towers are not a necessity! For a friend, who lived in Virginia, I went out into his woods and built a 5-element steerable 80/75m GP array that was a wonderful "kick-ass" antenna for long-haul 80/75m DX! So, I would think that you and your dad are pretty well set! Have fun!! 73, Charlie, K4OTV . -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Gary Smith Sent: Sunday, October 27, 2013 8:51 PM To: Topband@contesting.com Subject: Re: Topband: Balun Question Hi Charlie, the mast for his inv-V snapped during Hurricane Sandy and I attached the apex to the highest remaining part of the PVC mast that snapped, that I can reach up to. So for this moment, his Inv-V is more of a dipole with the apex 10-15 foot higher than the terminations. Next summer I'll wrangle the original assembly up for him and the apex will be another 30' higher than it is now. I had to fell a few trees that were interfering with the wires and now he has a clear space with no more interference. So no high conditions here, my INV-L is based 20' lower than the basement 350' away and is at the edge of a salt marsh with the wire over the tree tops. The highest part of my vertical run is maybe 20' higher than the apex of his V is today. No possible way to put up anything taller for either of us, no towers allowed. It's still a nice location though on the end of Long Island sound. 73, Gary KA1J > Hi, Gary > > Should do fine! The W2DU balun is a good current-mode design by > someone who > knew what he was doing! > > As for 160, I do have a W2DU current mode balun, from Unadilla that > is > longer that the 80-10m version (more beads) but I never really > pushed it. I > did use it some n 80m. Actually on 160, I didn't really have need > for a > balun with the inverted L antennas that I used. I expect that the > application for a 160 m balun is most likely for guy s with high > dipoles and > inverted Vees, and really big delta loops. The w2DU balun will > workat least > as well as, and probably better than, the W2AU balun that it woud > be > replacing! > > Hope your dad enjoys it for many more years! :-) > > 73, > Charlie, K4OTV > > > > -Original Message- > From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of > Gary > Smith > Sent: Sunday, October 27, 2013 7:45 PM > To: Topband@contesting.com > Subject: Re: Topband: Balun Question > > Fellows, > > Thanks for the on & off list replies, I just got back from a weekend > away & read through them all. Part of me wants to just leave it as > is > but that's not practical, a good icing and the connections I made > will fail. Since I need something to relieve stress from the > copperweld and the weight of the coax, the W2DU 1:1 looks like it > ought to cover the issues. > > There's no telling when bad weather will hit and once there'ssnow on > the roof I'm not going up to work on anything so I need to do it > now. > He only operates on 80M phone using a Viewstar PT-2500A amp so the > W2DU 1:1 ought to be fine. Someday when I'm the one using the > station > I'll want to use it on 160 and I'm not sure how well that balun will > do on 160 but that's for another time. > > Thank you all for the thoughts and helpful suggestions. > > 73, > > Gary > KA1J > > > Unfortunately, optimum balun impedance and design really depends > > heavily on > > the application,. There is no magic design that works best for > all > > applications, and the issue is so complex that almost any > article > > falls > > short. > > > > For example, the 5000 ohms pure R will not work at 1500 watts > with > > all > > antennas. With a balanced feeder having a balun termination > > impedance of > > 2000 ohms, a balun would have 1732V RMS between conductors, and > 866 > > volts to > > ground. CM voltage would be 866 across a perfect balun if the > feeder > > were > > perfectly balanced. The 5000 ohm CM impedance balun would > dissipate > > 150 > > watts in the cores, far beyond what any reasonable core stack > would > > tolerate. The fact the antenna comes out of balance reduces t
Re: Topband: Balun Question
Hi Charlie, the mast for his inv-V snapped during Hurricane Sandy and I attached the apex to the highest remaining part of the PVC mast that snapped, that I can reach up to. So for this moment, his Inv-V is more of a dipole with the apex 10-15 foot higher than the terminations. Next summer I'll wrangle the original assembly up for him and the apex will be another 30' higher than it is now. I had to fell a few trees that were interfering with the wires and now he has a clear space with no more interference. So no high conditions here, my INV-L is based 20' lower than the basement 350' away and is at the edge of a salt marsh with the wire over the tree tops. The highest part of my vertical run is maybe 20' higher than the apex of his V is today. No possible way to put up anything taller for either of us, no towers allowed. It's still a nice location though on the end of Long Island sound. 73, Gary KA1J > Hi, Gary > > Should do fine! The W2DU balun is a good current-mode design by > someone who > knew what he was doing! > > As for 160, I do have a W2DU current mode balun, from Unadilla that > is > longer that the 80-10m version (more beads) but I never really > pushed it. I > did use it some n 80m. Actually on 160, I didn't really have need > for a > balun with the inverted L antennas that I used. I expect that the > application for a 160 m balun is most likely for guy s with high > dipoles and > inverted Vees, and really big delta loops. The w2DU balun will > workat least > as well as, and probably better than, the W2AU balun that it woud > be > replacing! > > Hope your dad enjoys it for many more years! :-) > > 73, > Charlie, K4OTV > > > > -Original Message- > From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of > Gary > Smith > Sent: Sunday, October 27, 2013 7:45 PM > To: Topband@contesting.com > Subject: Re: Topband: Balun Question > > Fellows, > > Thanks for the on & off list replies, I just got back from a weekend > away & read through them all. Part of me wants to just leave it as > is > but that's not practical, a good icing and the connections I made > will fail. Since I need something to relieve stress from the > copperweld and the weight of the coax, the W2DU 1:1 looks like it > ought to cover the issues. > > There's no telling when bad weather will hit and once there'ssnow on > the roof I'm not going up to work on anything so I need to do it > now. > He only operates on 80M phone using a Viewstar PT-2500A amp so the > W2DU 1:1 ought to be fine. Someday when I'm the one using the > station > I'll want to use it on 160 and I'm not sure how well that balun will > do on 160 but that's for another time. > > Thank you all for the thoughts and helpful suggestions. > > 73, > > Gary > KA1J > > > Unfortunately, optimum balun impedance and design really depends > > heavily on > > the application,. There is no magic design that works best for > all > > applications, and the issue is so complex that almost any > article > > falls > > short. > > > > For example, the 5000 ohms pure R will not work at 1500 watts > with > > all > > antennas. With a balanced feeder having a balun termination > > impedance of > > 2000 ohms, a balun would have 1732V RMS between conductors, and > 866 > > volts to > > ground. CM voltage would be 866 across a perfect balun if the > feeder > > were > > perfectly balanced. The 5000 ohm CM impedance balun would > dissipate > > 150 > > watts in the cores, far beyond what any reasonable core stack > would > > tolerate. The fact the antenna comes out of balance reduces the > heat > > somewhat, but this clearly is a case where we WANT a reactive > > isolation > > impedance to reduce heat. > > > > Making things worse, a half wave antenna fed through 1/4 wave of > > open wire > > might have an impedance of 6000 ohms or more. The above example > was > > for 2000 > > ohms! > > > > Without much effort, we can see why simplistic "always do this" > > rules just > > don't work in the real world. > > > > Every situation has to be case-by-case. > > > > 73 Tom > > > > > > > > > > - Original Message - > > From: "Tom Boucher" > > To: "160 reflector" > > Sent: Friday, October 25, 2013 10:49 AM > > Subject: Topband: Balun Question > > > > > > > Gary KA1J - take a look at this excellent article on ferriste > > baluns by > > > GM3SEK: > > > > > > http://www.ifwtech.co.uk/g3sek/in-prac/inpr1005_ext_v2.pdf > > > > > > 73 > > > Tom G3OLB > > > _ > > > Topband Reflector > > > > > > > > > - > > > No virus found in this message. > > > Checked by AVG - www.avg.com > > > Version: 2014.0.4158 / Virus Database: 3614/6767 - Release > Date: > > 10/20/13 > > > > > > > _ > > Topband Reflector > > > > > > _ > Topband Reflector > > _ Topband Reflector
Re: Topband: Balun Question
Hi, Gary Should do fine! The W2DU balun is a good current-mode design by someone who knew what he was doing! As for 160, I do have a W2DU current mode balun, from Unadilla that is longer that the 80-10m version (more beads) but I never really pushed it. I did use it some n 80m. Actually on 160, I didn't really have need for a balun with the inverted L antennas that I used. I expect that the application for a 160 m balun is most likely for guy s with high dipoles and inverted Vees, and really big delta loops. The w2DU balun will workat least as well as, and probably better than, the W2AU balun that it woud be replacing! Hope your dad enjoys it for many more years! :-) 73, Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Gary Smith Sent: Sunday, October 27, 2013 7:45 PM To: Topband@contesting.com Subject: Re: Topband: Balun Question Fellows, Thanks for the on & off list replies, I just got back from a weekend away & read through them all. Part of me wants to just leave it as is but that's not practical, a good icing and the connections I made will fail. Since I need something to relieve stress from the copperweld and the weight of the coax, the W2DU 1:1 looks like it ought to cover the issues. There's no telling when bad weather will hit and once there'ssnow on the roof I'm not going up to work on anything so I need to do it now. He only operates on 80M phone using a Viewstar PT-2500A amp so the W2DU 1:1 ought to be fine. Someday when I'm the one using the station I'll want to use it on 160 and I'm not sure how well that balun will do on 160 but that's for another time. Thank you all for the thoughts and helpful suggestions. 73, Gary KA1J > Unfortunately, optimum balun impedance and design really depends > heavily on > the application,. There is no magic design that works best for all > applications, and the issue is so complex that almost any article > falls > short. > > For example, the 5000 ohms pure R will not work at 1500 watts with > all > antennas. With a balanced feeder having a balun termination > impedance of > 2000 ohms, a balun would have 1732V RMS between conductors, and 866 > volts to > ground. CM voltage would be 866 across a perfect balun if the feeder > were > perfectly balanced. The 5000 ohm CM impedance balun would dissipate > 150 > watts in the cores, far beyond what any reasonable core stack would > tolerate. The fact the antenna comes out of balance reduces the heat > somewhat, but this clearly is a case where we WANT a reactive > isolation > impedance to reduce heat. > > Making things worse, a half wave antenna fed through 1/4 wave of > open wire > might have an impedance of 6000 ohms or more. The above example was > for 2000 > ohms! > > Without much effort, we can see why simplistic "always do this" > rules just > don't work in the real world. > > Every situation has to be case-by-case. > > 73 Tom > > > > > - Original Message - > From: "Tom Boucher" > To: "160 reflector" > Sent: Friday, October 25, 2013 10:49 AM > Subject: Topband: Balun Question > > > > Gary KA1J - take a look at this excellent article on ferriste > baluns by > > GM3SEK: > > > > http://www.ifwtech.co.uk/g3sek/in-prac/inpr1005_ext_v2.pdf > > > > 73 > > Tom G3OLB > > _ > > Topband Reflector > > > > > > - > > No virus found in this message. > > Checked by AVG - www.avg.com > > Version: 2014.0.4158 / Virus Database: 3614/6767 - Release Date: > 10/20/13 > > > > _ > Topband Reflector > _ Topband Reflector _ Topband Reflector
Re: Topband: Balun Question
Fellows, Thanks for the on & off list replies, I just got back from a weekend away & read through them all. Part of me wants to just leave it as is but that's not practical, a good icing and the connections I made will fail. Since I need something to relieve stress from the copperweld and the weight of the coax, the W2DU 1:1 looks like it ought to cover the issues. There's no telling when bad weather will hit and once there'ssnow on the roof I'm not going up to work on anything so I need to do it now. He only operates on 80M phone using a Viewstar PT-2500A amp so the W2DU 1:1 ought to be fine. Someday when I'm the one using the station I'll want to use it on 160 and I'm not sure how well that balun will do on 160 but that's for another time. Thank you all for the thoughts and helpful suggestions. 73, Gary KA1J > Unfortunately, optimum balun impedance and design really depends > heavily on > the application,. There is no magic design that works best for all > applications, and the issue is so complex that almost any article > falls > short. > > For example, the 5000 ohms pure R will not work at 1500 watts with > all > antennas. With a balanced feeder having a balun termination > impedance of > 2000 ohms, a balun would have 1732V RMS between conductors, and 866 > volts to > ground. CM voltage would be 866 across a perfect balun if the feeder > were > perfectly balanced. The 5000 ohm CM impedance balun would dissipate > 150 > watts in the cores, far beyond what any reasonable core stack would > tolerate. The fact the antenna comes out of balance reduces the heat > somewhat, but this clearly is a case where we WANT a reactive > isolation > impedance to reduce heat. > > Making things worse, a half wave antenna fed through 1/4 wave of > open wire > might have an impedance of 6000 ohms or more. The above example was > for 2000 > ohms! > > Without much effort, we can see why simplistic "always do this" > rules just > don't work in the real world. > > Every situation has to be case-by-case. > > 73 Tom > > > > > - Original Message - > From: "Tom Boucher" > To: "160 reflector" > Sent: Friday, October 25, 2013 10:49 AM > Subject: Topband: Balun Question > > > > Gary KA1J - take a look at this excellent article on ferriste > baluns by > > GM3SEK: > > > > http://www.ifwtech.co.uk/g3sek/in-prac/inpr1005_ext_v2.pdf > > > > 73 > > Tom G3OLB > > _ > > Topband Reflector > > > > > > - > > No virus found in this message. > > Checked by AVG - www.avg.com > > Version: 2014.0.4158 / Virus Database: 3614/6767 - Release Date: > 10/20/13 > > > > _ > Topband Reflector > _ Topband Reflector
Re: Topband: Balun Question
Unfortunately, optimum balun impedance and design really depends heavily on the application,. There is no magic design that works best for all applications, and the issue is so complex that almost any article falls short. For example, the 5000 ohms pure R will not work at 1500 watts with all antennas. With a balanced feeder having a balun termination impedance of 2000 ohms, a balun would have 1732V RMS between conductors, and 866 volts to ground. CM voltage would be 866 across a perfect balun if the feeder were perfectly balanced. The 5000 ohm CM impedance balun would dissipate 150 watts in the cores, far beyond what any reasonable core stack would tolerate. The fact the antenna comes out of balance reduces the heat somewhat, but this clearly is a case where we WANT a reactive isolation impedance to reduce heat. Making things worse, a half wave antenna fed through 1/4 wave of open wire might have an impedance of 6000 ohms or more. The above example was for 2000 ohms! Without much effort, we can see why simplistic "always do this" rules just don't work in the real world. Every situation has to be case-by-case. 73 Tom - Original Message - From: "Tom Boucher" To: "160 reflector" Sent: Friday, October 25, 2013 10:49 AM Subject: Topband: Balun Question Gary KA1J - take a look at this excellent article on ferriste baluns by GM3SEK: http://www.ifwtech.co.uk/g3sek/in-prac/inpr1005_ext_v2.pdf 73 Tom G3OLB _ Topband Reflector - No virus found in this message. Checked by AVG - www.avg.com Version: 2014.0.4158 / Virus Database: 3614/6767 - Release Date: 10/20/13 _ Topband Reflector
Topband: Balun Question
Gary KA1J - take a look at this excellent article on ferriste baluns by GM3SEK: http://www.ifwtech.co.uk/g3sek/in-prac/inpr1005_ext_v2.pdf 73 Tom G3OLB _ Topband Reflector
Re: Topband: Balun question
A W2DU balun, however is another story! Walt knew what he was doing! 73, Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Tom W8JI Sent: Thursday, October 24, 2013 8:41 PM To: g...@ka1j.com; topband@contesting.com Subject: Re: Topband: Balun question > Though this reflector is for 160M I have an 80M question that might > be best asked here. My father W1BML is on an 80 meter net nightly. > His antenna in an inv-V with 40 & 80 elements though he never uses 40 > any more. I needed to fell a couple of trees to remove branches that > were touching his copperweld and the W2AU balun he had broke in two > during the process. (Don't ask, your imagination is probably correct) > :) And he would like it put back the way it was, with a balun. He's > 96 so I try to keep him happy. > > I'm thinking 10 or so rolls of coax around 1' in diameter ought to be > fine for a choke on 80. Any better suggestions? Gary, The W2AU balun he was happy with isn't a balun at all...it basically has NO common mode suppression. The impedance of a few turns of coax is also next to nothing on 80 meters, but almost everyone is "happy" with them. As a matter of fact, if the feedline from the antenna to the ground point of the coax is 30-45 feet long, it would need no balun at all for good common mode suppression. This illustrates some of the ridiculous "overkill" we are all caught up in. Since he was happy with his non-suppression balun, just use anything he thinks is a balun. He will be just as happy. A sting of beads of any impedance, a few turns of coax, a big coil of coax, if he didn't notice the W2AU balun causing a problem anything you put there will make him happy. :) 73 Tom 73 Tom _ Topband Reflector _ Topband Reflector
Re: Topband: Balun question
True! -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Tom W8JI Sent: Thursday, October 24, 2013 8:41 PM To: g...@ka1j.com; topband@contesting.com Subject: Re: Topband: Balun question > Though this reflector is for 160M I have an 80M question that might > be best asked here. My father W1BML is on an 80 meter net nightly. > His antenna in an inv-V with 40 & 80 elements though he never uses 40 > any more. I needed to fell a couple of trees to remove branches that > were touching his copperweld and the W2AU balun he had broke in two > during the process. (Don't ask, your imagination is probably correct) > :) And he would like it put back the way it was, with a balun. He's > 96 so I try to keep him happy. > > I'm thinking 10 or so rolls of coax around 1' in diameter ought to be > fine for a choke on 80. Any better suggestions? Gary, The W2AU balun he was happy with isn't a balun at all...it basically has NO common mode suppression. The impedance of a few turns of coax is also next to nothing on 80 meters, but almost everyone is "happy" with them. As a matter of fact, if the feedline from the antenna to the ground point of the coax is 30-45 feet long, it would need no balun at all for good common mode suppression. This illustrates some of the ridiculous "overkill" we are all caught up in. Since he was happy with his non-suppression balun, just use anything he thinks is a balun. He will be just as happy. A sting of beads of any impedance, a few turns of coax, a big coil of coax, if he didn't notice the W2AU balun causing a problem anything you put there will make him happy. :) 73 Tom 73 Tom _ Topband Reflector _ Topband Reflector
Re: Topband: Balun question
Though this reflector is for 160M I have an 80M question that might be best asked here. My father W1BML is on an 80 meter net nightly. His antenna in an inv-V with 40 & 80 elements though he never uses 40 any more. I needed to fell a couple of trees to remove branches that were touching his copperweld and the W2AU balun he had broke in two during the process. (Don't ask, your imagination is probably correct) :) And he would like it put back the way it was, with a balun. He's 96 so I try to keep him happy. I'm thinking 10 or so rolls of coax around 1' in diameter ought to be fine for a choke on 80. Any better suggestions? Gary, The W2AU balun he was happy with isn't a balun at all...it basically has NO common mode suppression. The impedance of a few turns of coax is also next to nothing on 80 meters, but almost everyone is "happy" with them. As a matter of fact, if the feedline from the antenna to the ground point of the coax is 30-45 feet long, it would need no balun at all for good common mode suppression. This illustrates some of the ridiculous "overkill" we are all caught up in. Since he was happy with his non-suppression balun, just use anything he thinks is a balun. He will be just as happy. A sting of beads of any impedance, a few turns of coax, a big coil of coax, if he didn't notice the W2AU balun causing a problem anything you put there will make him happy. :) 73 Tom 73 Tom _ Topband Reflector
Re: Topband: Balun question
Just teasin' you, Randy! J I think the snap-ons would be quick, simple and very effective and should outlast the antenna, I expect! From: Randy Lake [mailto:randyn1...@gmail.com] Sent: Thursday, October 24, 2013 7:58 PM To: Charlie Cunningham Cc: Jim Bennett; g...@ka1j.com; topband@contesting.com Subject: Re: Topband: Balun question I am sorry! That was not very clear. The info on chokes worked wonderfully for me on 80m and 160m using the Big 31 snap-ons. Not only that but lots of good info other than chokes. Randy On Thu, Oct 24, 2013 at 7:55 PM, Charlie Cunningham wrote: What "works flawlessly", Randy? The link? J 73, Charlie, K4OTV From: Randy Lake [mailto:randyn1...@gmail.com] Sent: Thursday, October 24, 2013 7:51 PM To: Charlie Cunningham Cc: Jim Bennett; g...@ka1j.com; topband@contesting.com Subject: Re: Topband: Balun question Check this link out. It works flawlessly. audiosystemsgroup.com/RFI-Ham.pdf On Thu, Oct 24, 2013 at 7:47 PM, Charlie Cunningham wrote: That would work as well. I used something similar, but with less turns to precede the 4:1 current balun feeding the drivers on my home brew 5-band quad. Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Jim Bennett Sent: Thursday, October 24, 2013 7:41 PM To: g...@ka1j.com Cc: topband@contesting.com Subject: Re: Topband: Balun question I was just looking through the ARRL Antenna Book - if it's RG-8, then 8 turns would work if wound on an 8 inch PVC tube. However, that size PVC may be difficult to find, and certainly wouldn't be to spiffy hung way up the air. But then again, you were thinking about 10 turns on a 12 inch diameter form...? I assume you were going to place it at the apex of the Inverted Vee, right? An alternative would be to get 5 mix 31 ferrite cores, 2.4 inch OD and pass the coax through it six times. That ought to get about 5,000 ohm impedance at 3.5 MHz and would do the trick. I'm using exactly that on my 80 meter Inverted L and it does a fine job. Mouser has those cores for $6-$7 each. Jim / W6JHB On Thursday, Oct 24, 2013, at Thursday, 4:25 PM, Gary Smith wrote: > Though this reflector is for 160M I have an 80M question that might be > best asked here. My father W1BML is on an 80 meter net nightly. > His antenna in an inv-V with 40 & 80 elements though he never uses 40 > any more. I needed to fell a couple of trees to remove branches that > were touching his copperweld and the W2AU balun he had broke in two > during the process. (Don't ask, your imagination is probably correct) > :) And he would like it put back the way it was, with a balun. He's > 96 so I try to keep him happy. > > I'm thinking 10 or so rolls of coax around 1' in diameter ought to be > fine for a choke on 80. Any better suggestions? > > Thanks, > > Gary > KA1J > _ > Topband Reflector _ Topband Reflector _ Topband Reflector -- Randy Lake N1KWF 73 Gunn Rd. Keene,NH -- Randy Lake N1KWF 73 Gunn Rd. Keene,NH _ Topband Reflector
Re: Topband: Balun question
I am sorry! That was not very clear. The info on chokes worked wonderfully for me on 80m and 160m using the Big 31 snap-ons. Not only that but lots of good info other than chokes. Randy On Thu, Oct 24, 2013 at 7:55 PM, Charlie Cunningham < charlie-cunning...@nc.rr.com> wrote: > What “works flawlessly”, Randy? The link? J > > ** ** > > 73, > > Charlie, K4OTV > > ** ** > > *From:* Randy Lake [mailto:randyn1...@gmail.com] > *Sent:* Thursday, October 24, 2013 7:51 PM > *To:* Charlie Cunningham > *Cc:* Jim Bennett; g...@ka1j.com; topband@contesting.com > *Subject:* Re: Topband: Balun question > > ** ** > > Check this link out. It works flawlessly. > > audiosystemsgroup.com/*RFI*-Ham.pdf > > ** ** > > On Thu, Oct 24, 2013 at 7:47 PM, Charlie Cunningham < > charlie-cunning...@nc.rr.com> wrote: > > That would work as well. I used something similar, but with less turns to > precede the 4:1 current balun feeding the drivers on my home brew 5-band > quad. > > Charlie, K4OTV > > > -Original Message- > From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Jim > Bennett > Sent: Thursday, October 24, 2013 7:41 PM > To: g...@ka1j.com > Cc: topband@contesting.com > Subject: Re: Topband: Balun question > > I was just looking through the ARRL Antenna Book - if it's RG-8, then 8 > turns would work if wound on an 8 inch PVC tube. However, that size PVC may > be difficult to find, and certainly wouldn't be to spiffy hung way up the > air. But then again, you were thinking about 10 turns on a 12 inch diameter > form...? I assume you were going to place it at the apex of the Inverted > Vee, right? An alternative would be to get 5 mix 31 ferrite cores, 2.4 inch > OD and pass the coax through it six times. That ought to get about 5,000 > ohm > impedance at 3.5 MHz and would do the trick. I'm using exactly that on my > 80 > meter Inverted L and it does a fine job. Mouser has those cores for $6-$7 > each. > > Jim / W6JHB > > > On Thursday, Oct 24, 2013, at Thursday, 4:25 PM, Gary Smith wrote: > > > Though this reflector is for 160M I have an 80M question that might be > > best asked here. My father W1BML is on an 80 meter net nightly. > > His antenna in an inv-V with 40 & 80 elements though he never uses 40 > > any more. I needed to fell a couple of trees to remove branches that > > were touching his copperweld and the W2AU balun he had broke in two > > during the process. (Don't ask, your imagination is probably correct) > > :) And he would like it put back the way it was, with a balun. He's > > 96 so I try to keep him happy. > > > > I'm thinking 10 or so rolls of coax around 1' in diameter ought to be > > fine for a choke on 80. Any better suggestions? > > > > Thanks, > > > > Gary > > KA1J > > _ > > Topband Reflector > > _ > Topband Reflector > > _ > Topband Reflector > > > > > > ** ** > > -- > Randy Lake N1KWF > 73 Gunn Rd. > Keene,NH > -- Randy Lake N1KWF 73 Gunn Rd. Keene,NH _ Topband Reflector
Re: Topband: Balun question
What "works flawlessly", Randy? The link? J 73, Charlie, K4OTV From: Randy Lake [mailto:randyn1...@gmail.com] Sent: Thursday, October 24, 2013 7:51 PM To: Charlie Cunningham Cc: Jim Bennett; g...@ka1j.com; topband@contesting.com Subject: Re: Topband: Balun question Check this link out. It works flawlessly. audiosystemsgroup.com/RFI-Ham.pdf On Thu, Oct 24, 2013 at 7:47 PM, Charlie Cunningham wrote: That would work as well. I used something similar, but with less turns to precede the 4:1 current balun feeding the drivers on my home brew 5-band quad. Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Jim Bennett Sent: Thursday, October 24, 2013 7:41 PM To: g...@ka1j.com Cc: topband@contesting.com Subject: Re: Topband: Balun question I was just looking through the ARRL Antenna Book - if it's RG-8, then 8 turns would work if wound on an 8 inch PVC tube. However, that size PVC may be difficult to find, and certainly wouldn't be to spiffy hung way up the air. But then again, you were thinking about 10 turns on a 12 inch diameter form...? I assume you were going to place it at the apex of the Inverted Vee, right? An alternative would be to get 5 mix 31 ferrite cores, 2.4 inch OD and pass the coax through it six times. That ought to get about 5,000 ohm impedance at 3.5 MHz and would do the trick. I'm using exactly that on my 80 meter Inverted L and it does a fine job. Mouser has those cores for $6-$7 each. Jim / W6JHB On Thursday, Oct 24, 2013, at Thursday, 4:25 PM, Gary Smith wrote: > Though this reflector is for 160M I have an 80M question that might be > best asked here. My father W1BML is on an 80 meter net nightly. > His antenna in an inv-V with 40 & 80 elements though he never uses 40 > any more. I needed to fell a couple of trees to remove branches that > were touching his copperweld and the W2AU balun he had broke in two > during the process. (Don't ask, your imagination is probably correct) > :) And he would like it put back the way it was, with a balun. He's > 96 so I try to keep him happy. > > I'm thinking 10 or so rolls of coax around 1' in diameter ought to be > fine for a choke on 80. Any better suggestions? > > Thanks, > > Gary > KA1J > _ > Topband Reflector _ Topband Reflector _ Topband Reflector -- Randy Lake N1KWF 73 Gunn Rd. Keene,NH _ Topband Reflector
Re: Topband: Balun question
Check this link out. It works flawlessly. audiosystemsgroup.com/*RFI*-Ham.pdf On Thu, Oct 24, 2013 at 7:47 PM, Charlie Cunningham < charlie-cunning...@nc.rr.com> wrote: > That would work as well. I used something similar, but with less turns to > precede the 4:1 current balun feeding the drivers on my home brew 5-band > quad. > > Charlie, K4OTV > > -Original Message- > From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Jim > Bennett > Sent: Thursday, October 24, 2013 7:41 PM > To: g...@ka1j.com > Cc: topband@contesting.com > Subject: Re: Topband: Balun question > > I was just looking through the ARRL Antenna Book - if it's RG-8, then 8 > turns would work if wound on an 8 inch PVC tube. However, that size PVC may > be difficult to find, and certainly wouldn't be to spiffy hung way up the > air. But then again, you were thinking about 10 turns on a 12 inch diameter > form...? I assume you were going to place it at the apex of the Inverted > Vee, right? An alternative would be to get 5 mix 31 ferrite cores, 2.4 inch > OD and pass the coax through it six times. That ought to get about 5,000 > ohm > impedance at 3.5 MHz and would do the trick. I'm using exactly that on my > 80 > meter Inverted L and it does a fine job. Mouser has those cores for $6-$7 > each. > > Jim / W6JHB > > > On Thursday, Oct 24, 2013, at Thursday, 4:25 PM, Gary Smith wrote: > > > Though this reflector is for 160M I have an 80M question that might be > > best asked here. My father W1BML is on an 80 meter net nightly. > > His antenna in an inv-V with 40 & 80 elements though he never uses 40 > > any more. I needed to fell a couple of trees to remove branches that > > were touching his copperweld and the W2AU balun he had broke in two > > during the process. (Don't ask, your imagination is probably correct) > > :) And he would like it put back the way it was, with a balun. He's > > 96 so I try to keep him happy. > > > > I'm thinking 10 or so rolls of coax around 1' in diameter ought to be > > fine for a choke on 80. Any better suggestions? > > > > Thanks, > > > > Gary > > KA1J > > _ > > Topband Reflector > > _ > Topband Reflector > > _ > Topband Reflector > -- Randy Lake N1KWF 73 Gunn Rd. Keene,NH _ Topband Reflector
Re: Topband: Balun question
That would work as well. I used something similar, but with less turns to precede the 4:1 current balun feeding the drivers on my home brew 5-band quad. Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Jim Bennett Sent: Thursday, October 24, 2013 7:41 PM To: g...@ka1j.com Cc: topband@contesting.com Subject: Re: Topband: Balun question I was just looking through the ARRL Antenna Book - if it's RG-8, then 8 turns would work if wound on an 8 inch PVC tube. However, that size PVC may be difficult to find, and certainly wouldn't be to spiffy hung way up the air. But then again, you were thinking about 10 turns on a 12 inch diameter form...? I assume you were going to place it at the apex of the Inverted Vee, right? An alternative would be to get 5 mix 31 ferrite cores, 2.4 inch OD and pass the coax through it six times. That ought to get about 5,000 ohm impedance at 3.5 MHz and would do the trick. I'm using exactly that on my 80 meter Inverted L and it does a fine job. Mouser has those cores for $6-$7 each. Jim / W6JHB On Thursday, Oct 24, 2013, at Thursday, 4:25 PM, Gary Smith wrote: > Though this reflector is for 160M I have an 80M question that might be > best asked here. My father W1BML is on an 80 meter net nightly. > His antenna in an inv-V with 40 & 80 elements though he never uses 40 > any more. I needed to fell a couple of trees to remove branches that > were touching his copperweld and the W2AU balun he had broke in two > during the process. (Don't ask, your imagination is probably correct) > :) And he would like it put back the way it was, with a balun. He's > 96 so I try to keep him happy. > > I'm thinking 10 or so rolls of coax around 1' in diameter ought to be > fine for a choke on 80. Any better suggestions? > > Thanks, > > Gary > KA1J > _ > Topband Reflector _ Topband Reflector _ Topband Reflector
Re: Topband: Balun question
Well, might work. Another idea though, check with Fair-Rite - I believe that they have some cores that wil fit over .405 RG-8, and I know they have lots that sill fit over RG-58 or RG-8X. If you don't mind removing the connector, you can just slip a bunch of them over the end of the cable and use wire ties to keep them from sliding up and down the cable. I've left them out in the weather for years with no adverse effects. They also have snap-ons if you don't' want to remove the connector. About the only thing that the PVC tube around that W2AU balun does is hold the connectors ( and maybe trap moisture). You didn't say what kind of cable, but winding RG-8 around a 1" form can be sort of a pain! 73, Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Gary Smith Sent: Thursday, October 24, 2013 7:25 PM To: topband@contesting.com Subject: Topband: Balun question Though this reflector is for 160M I have an 80M question that might be best asked here. My father W1BML is on an 80 meter net nightly. His antenna in an inv-V with 40 & 80 elements though he never uses 40 any more. I needed to fell a couple of trees to remove branches that were touching his copperweld and the W2AU balun he had broke in two during the process. (Don't ask, your imagination is probably correct) :) And he would like it put back the way it was, with a balun. He's 96 so I try to keep him happy. I'm thinking 10 or so rolls of coax around 1' in diameter ought to be fine for a choke on 80. Any better suggestions? Thanks, Gary KA1J _ Topband Reflector _ Topband Reflector
Re: Topband: Balun question
I was just looking through the ARRL Antenna Book - if it's RG-8, then 8 turns would work if wound on an 8 inch PVC tube. However, that size PVC may be difficult to find, and certainly wouldn't be to spiffy hung way up the air. But then again, you were thinking about 10 turns on a 12 inch diameter form...? I assume you were going to place it at the apex of the Inverted Vee, right? An alternative would be to get 5 mix 31 ferrite cores, 2.4 inch OD and pass the coax through it six times. That ought to get about 5,000 ohm impedance at 3.5 MHz and would do the trick. I'm using exactly that on my 80 meter Inverted L and it does a fine job. Mouser has those cores for $6-$7 each. Jim / W6JHB On Thursday, Oct 24, 2013, at Thursday, 4:25 PM, Gary Smith wrote: > Though this reflector is for 160M I have an 80M question that might > be best asked here. My father W1BML is on an 80 meter net nightly. > His antenna in an inv-V with 40 & 80 elements though he never uses 40 > any more. I needed to fell a couple of trees to remove branches that > were touching his copperweld and the W2AU balun he had broke in two > during the process. (Don't ask, your imagination is probably correct) > :) And he would like it put back the way it was, with a balun. He's > 96 so I try to keep him happy. > > I'm thinking 10 or so rolls of coax around 1' in diameter ought to be > fine for a choke on 80. Any better suggestions? > > Thanks, > > Gary > KA1J > _ > Topband Reflector _ Topband Reflector
Topband: Balun question
Though this reflector is for 160M I have an 80M question that might be best asked here. My father W1BML is on an 80 meter net nightly. His antenna in an inv-V with 40 & 80 elements though he never uses 40 any more. I needed to fell a couple of trees to remove branches that were touching his copperweld and the W2AU balun he had broke in two during the process. (Don't ask, your imagination is probably correct) :) And he would like it put back the way it was, with a balun. He's 96 so I try to keep him happy. I'm thinking 10 or so rolls of coax around 1' in diameter ought to be fine for a choke on 80. Any better suggestions? Thanks, Gary KA1J _ Topband Reflector
