Topband: THE ITINERANT 160 METER ANTENNA PROJECT - Follow Up
My previous request for suggestions for a relatively simple/transportable TB ant got some responses that have been incorporated into a design and construction that might be useful to others. It is a dual band 160/80 trapped vertical/T with two load top wires and two elevated gull wing radials using the spiderbeam 60' mast. It is relatively compact and works respectably on 160 and perhaps somewhat better on 80. Highlights are only 55' of the mast is useful (bending), radials are 75' (tuned to 80) and ~ 17' high, the 2 top load wires are 60' (tuned to 160), trap is coax type (Low-Z wired), a single hairpin match shunt coil setting allows no-tuner 160/80 use without any switching with limited BW and use on 160 requires a GOOD common-mode choke (this is a rather OCF antenna on 160). The hairpin matching requires patient trimming of wire lengths so if you are willing to complicate things a bit, a capacitor could be tossed in for an L-match. It is also very likely that putting this antenna up at another location would force a revisit to the tuning issues. As always YMMV. See http://n6mw.ehpes.com for details - at the end of the antenna project list. Bill, N6MW _ Topband Reflector
Re: Topband: THE ITINERANT 160 METER ANTENNA PROJECT
I have been clobbered every time I mention this. Is there some one other than me that knows the following I had read in a Hand Book for the 1930's the 3 wire folded dipole and 2 wire folded dipole had a couple factor of 1. This would make this antenna the preferred driven element for a long yagi. Folded dipoles are all so used when installations require long lengths of feed line. Back when the Bazooka or Double Bazooka or other wise now known as coaxial antenna back around 1970 I think when I saw it in Ham Radio Mag.. Its coupling factor was around 0.9 No some had told me that later on the coupling fact was really Velocity Factor. Now how can the velocity factor gets interpreted as to how well a driven element couples when compared to gamma match elements or Dipole or a folded dipole or bazooka? See, Ham Radio Techniques - 160-Meter Antenna Problems and Solutions, Ham Radio magazine, Pg. 49, March 1990. A 3-wire version is also proposed to increase the radiation resistance by 9x. In the single and multi-wire folded versions the ground loss resistance remained constant. Note that Bill was obtaining his results from the K6STI antenna modeling software he was using. I am not familiar with that program's capabilities or accuracy and it is clear from the article he believed the results he obtained from it. It was the early days of NEC programs for PCs and many of us were just learning how to use and apply the antenna simulation programs. It is impossible to know the basis for his errors in this case. But Bill's contributions to amateur radio were vast and valuable and greatly overshadow this one slip-up. '73, Thomas - ac7a (Tucson) - Stay on course, fight a good fight, and keep the faith. Jim K9TF/WA9YSD ___ UR RST IS ... ... ..9 QSB QSB - hw? BK
Re: Topband: THE ITINERANT 160 METER ANTENNA PROJECT
TOM You said 3.) Use the largest counterpoise possible, and use one that does not concentrate current, zig-zag current all around, or produce unnecessarily high voltages. In 300 words or less please explain again Zig-zag current? Stay on course, fight a good fight, and keep the faith. Jim K9TF/WA9YSD From: Jim WA9YSD wa9...@yahoo.com To: Top Band topband@contesting.com Sent: Sunday, August 5, 2012 7:59 AM Subject: Re: THE ITINERANT 160 METER ANTENNA PROJECT I have been clobbered every time I mention this. Is there some one other than me that knows the following I had read in a Hand Book for the 1930's the 3 wire folded dipole and 2 wire folded dipole had a couple factor of 1. This would make this antenna the preferred driven element for a long yagi. Folded dipoles are all so used when installations require long lengths of feed line. Back when the Bazooka or Double Bazooka or other wise now known as coaxial antenna back around 1970 I think when I saw it in Ham Radio Mag.. Its coupling factor was around 0.9 No some had told me that later on the coupling fact was really Velocity Factor. Now how can the velocity factor gets interpreted as to how well a driven element couples when compared to gamma match elements or Dipole or a folded dipole or bazooka? See, Ham Radio Techniques - 160-Meter Antenna Problems and Solutions, Ham Radio magazine, Pg. 49, March 1990. A 3-wire version is also proposed to increase the radiation resistance by 9x. In the single and multi-wire folded versions the ground loss resistance remained constant. Note that Bill was obtaining his results from the K6STI antenna modeling software he was using. I am not familiar with that program's capabilities or accuracy and it is clear from the article he believed the results he obtained from it. It was the early days of NEC programs for PCs and many of us were just learning how to use and apply the antenna simulation programs. It is impossible to know the basis for his errors in this case. But Bill's contributions to amateur radio were vast and valuable and greatly overshadow this one slip-up. '73, Thomas - ac7a (Tucson) - Stay on course, fight a good fight, and keep the faith. Jim K9TF/WA9YSD ___ UR RST IS ... ... ..9 QSB QSB - hw? BK
Re: Topband: THE ITINERANT 160 METER ANTENNA PROJECT
I had read in a Hand Book for the 1930's the 3 wire folded dipole and 2 wire folded dipole had a couple factor of 1. This would make this antenna the preferred driven element for a long yagi. Why? Unless we know what they meant by the use of the phrase coupling factor, we can't possibly extrapolate the meaning to infer anything about coupling in a Yagi. I have not seen the exact text, but most likely they mean coupling from one conductor to the next inside the dipiole is unitywhich has nothing to do with how that group of conductors couples to anything else in the world. It would really only mean that group of conductors or wires behaves as one conductor or wire. Folded dipoles are all so used when installations require long lengths of feed line. Only because their impedance closely matches the impedance of low-loss open wire lines available years ago. This meant the open wire line operated with a low SWR on the band the dipole was cut for. Other than feed impedance, they are just a dipole. They have the same radiation resistance as a regular dipole, using the IRE definition of radiation resistance. The only changed is impedance seen by the feedline. Back when the Bazooka or Double Bazooka or other wise now known as coaxial antenna back around 1970 I think when I saw it in Ham Radio Mag.. Its coupling factor was around 0.9 That antenna was entirely false in theory and concept. The article, as I recall, did not accurately describe how the antenna worked. That antenna is just a thick dipole with a stub across the feedpoint. The stub internal conductors and the coax jacket introduces a little loss, so it has LESS gain than a regular dipole. I was aware of the antenna because a person who worked for me started raving about them, and selling them. His supposition, based on the article, was they had gain and had increased bandwidth, and less noise. The theory made no sense on paper, and when I compared one to a regular dipole the same material and thickness they were identical, as near as I could tell. No some had told me that later on the coupling fact was really Velocity Factor. Now how can the velocity factor gets interpreted as to how well a driven element couples when compared to gamma match elements or Dipole or a folded dipole or bazooka? It doesn't. Don't believe everything you read. One book we have, considered to be a bible on baluns, starts on the second page with a misconception of balance and the behavior of dipoles and coaxial lines, and a flawed test to prove the theory. The entire book is about balance, and the foundation shows a misunderstanding of the cause of common mode current. This why, later in the book, a balun that isn't even a balun is described. This is a hobby without much peer review, and yet we expect people, articles, or books we hold in high esteem to be right 100% of the time. This doesn't mean they are worthless, just that we need to understand things are not flawless. 73 Tom ___ UR RST IS ... ... ..9 QSB QSB - hw? BK
Re: Topband: THE ITINERANT 160 METER ANTENNA PROJECT
You said 3.) Use the largest counterpoise possible, and use one that does not concentrate current, zig-zag current all around, or produce unnecessarily high voltages. In 300 words or less please explain again Zig-zag current? Jim, While some forms of coiling, folding, and bending are better than others at accomplishing different things, the general rule is we want to keep counterpoise wires for a Marconi antenna as straight as possible away from the antenna base. This is because we generally want displacement currents, which are what allow reduction of current along the length of the radiator and allow current flow out to an open end, to have a short straight low-loss path back to the antenna base and to not create more displacement current inside conductor paths than necessary. http://en.wikipedia.org/wiki/Displacement_current Without displacement currents, Kirchhoff's laws cannot be satisfied in AC circuits involving capacitances, either lumped as a component or distributed along conductors. 73 Tom ___ UR RST IS ... ... ..9 QSB QSB - hw? BK
Re: Topband: THE ITINERANT 160 METER ANTENNA PROJECT
I ran comparisons side by side over the years with folded dipoles, bazookas against just a plain Jane wire dipole. You can believe what you read. Stay on course, fight a good fight, and keep the faith. Jim K9TF/WA9YSD From: Tom W8JI w...@w8ji.com To: Jim WA9YSD wa9...@yahoo.com; Top Band topband@contesting.com Sent: Sunday, August 5, 2012 8:58 AM Subject: Re: Topband: THE ITINERANT 160 METER ANTENNA PROJECT I had read in a Hand Book for the 1930's the 3 wire folded dipole and 2 wire folded dipole had a couple factor of 1. This would make this antenna the preferred driven element for a long yagi. Why? Unless we know what they meant by the use of the phrase coupling factor, we can't possibly extrapolate the meaning to infer anything about coupling in a Yagi. I have not seen the exact text, but most likely they mean coupling from one conductor to the next inside the dipiole is unitywhich has nothing to do with how that group of conductors couples to anything else in the world. It would really only mean that group of conductors or wires behaves as one conductor or wire. Folded dipoles are all so used when installations require long lengths of feed line. Only because their impedance closely matches the impedance of low-loss open wire lines available years ago. This meant the open wire line operated with a low SWR on the band the dipole was cut for. Other than feed impedance, they are just a dipole. They have the same radiation resistance as a regular dipole, using the IRE definition of radiation resistance. The only changed is impedance seen by the feedline. Back when the Bazooka or Double Bazooka or other wise now known as coaxial antenna back around 1970 I think when I saw it in Ham Radio Mag.. Its coupling factor was around 0.9 That antenna was entirely false in theory and concept. The article, as I recall, did not accurately describe how the antenna worked. That antenna is just a thick dipole with a stub across the feedpoint. The stub internal conductors and the coax jacket introduces a little loss, so it has LESS gain than a regular dipole. I was aware of the antenna because a person who worked for me started raving about them, and selling them. His supposition, based on the article, was they had gain and had increased bandwidth, and less noise. The theory made no sense on paper, and when I compared one to a regular dipole the same material and thickness they were identical, as near as I could tell. No some had told me that later on the coupling fact was really Velocity Factor. Now how can the velocity factor gets interpreted as to how well a driven element couples when compared to gamma match elements or Dipole or a folded dipole or bazooka? It doesn't. Don't believe everything you read. One book we have, considered to be a bible on baluns, starts on the second page with a misconception of balance and the behavior of dipoles and coaxial lines, and a flawed test to prove the theory. The entire book is about balance, and the foundation shows a misunderstanding of the cause of common mode current. This why, later in the book, a balun that isn't even a balun is described. This is a hobby without much peer review, and yet we expect people, articles, or books we hold in high esteem to be right 100% of the time. This doesn't mean they are worthless, just that we need to understand things are not flawless. 73 Tom ___ UR RST IS ... ... ..9 QSB QSB - hw? BK
Re: Topband: THE ITINERANT 160 METER ANTENNA PROJECT
Jim-- Forgive me, but this is a completely ambiguous statement. I have read many conflicting statements on this subject. So, how can I believe what I read? Please be specific about what you mean, and your test results. Bill--W4BSG -Original Message- From: Jim WA9YSD Sent: Sunday, August 05, 2012 10:14 AM To: Top Band Subject: Re: Topband: THE ITINERANT 160 METER ANTENNA PROJECT I ran comparisons side by side over the years with folded dipoles, bazookas against just a plain Jane wire dipole. You can believe what you read. Stay on course, fight a good fight, and keep the faith. Jim K9TF/WA9YSD From: Tom W8JI w...@w8ji.com To: Jim WA9YSD wa9...@yahoo.com; Top Band topband@contesting.com Sent: Sunday, August 5, 2012 8:58 AM Subject: Re: Topband: THE ITINERANT 160 METER ANTENNA PROJECT I had read in a Hand Book for the 1930's the 3 wire folded dipole and 2 wire folded dipole had a couple factor of 1. This would make this antenna the preferred driven element for a long yagi. Why? Unless we know what they meant by the use of the phrase coupling factor, we can't possibly extrapolate the meaning to infer anything about coupling in a Yagi. I have not seen the exact text, but most likely they mean coupling from one conductor to the next inside the dipiole is unitywhich has nothing to do with how that group of conductors couples to anything else in the world. It would really only mean that group of conductors or wires behaves as one conductor or wire. Folded dipoles are all so used when installations require long lengths of feed line. Only because their impedance closely matches the impedance of low-loss open wire lines available years ago. This meant the open wire line operated with a low SWR on the band the dipole was cut for. Other than feed impedance, they are just a dipole. They have the same radiation resistance as a regular dipole, using the IRE definition of radiation resistance. The only changed is impedance seen by the feedline. Back when the Bazooka or Double Bazooka or other wise now known as coaxial antenna back around 1970 I think when I saw it in Ham Radio Mag.. Its coupling factor was around 0.9 That antenna was entirely false in theory and concept. The article, as I recall, did not accurately describe how the antenna worked. That antenna is just a thick dipole with a stub across the feedpoint. The stub internal conductors and the coax jacket introduces a little loss, so it has LESS gain than a regular dipole. I was aware of the antenna because a person who worked for me started raving about them, and selling them. His supposition, based on the article, was they had gain and had increased bandwidth, and less noise. The theory made no sense on paper, and when I compared one to a regular dipole the same material and thickness they were identical, as near as I could tell. No some had told me that later on the coupling fact was really Velocity Factor. Now how can the velocity factor gets interpreted as to how well a driven element couples when compared to gamma match elements or Dipole or a folded dipole or bazooka? It doesn't. Don't believe everything you read. One book we have, considered to be a bible on baluns, starts on the second page with a misconception of balance and the behavior of dipoles and coaxial lines, and a flawed test to prove the theory. The entire book is about balance, and the foundation shows a misunderstanding of the cause of common mode current. This why, later in the book, a balun that isn't even a balun is described. This is a hobby without much peer review, and yet we expect people, articles, or books we hold in high esteem to be right 100% of the time. This doesn't mean they are worthless, just that we need to understand things are not flawless. 73 Tom ___ UR RST IS ... ... ..9 QSB QSB - hw? BK ___ UR RST IS ... ... ..9 QSB QSB - hw? BK
Re: Topband: THE ITINERANT 160 METER ANTENNA PROJECT
OK, thanks all for that info, its obviously something I havent read altho I have those HB's. Carl KM1H - Original Message - From: Dave Heil k...@frontiernet.net To: topband@contesting.com Sent: Friday, August 03, 2012 12:44 AM Subject: Re: Topband: THE ITINERANT 160 METER ANTENNA PROJECT Wes et al, The claim was made in the last several editions of the Radio Handbook in describing a TV twinlead folded Marconi for 160m. 73, Dave Heil K8MN On 8/3/2012 01 18, Wes Attaway (N5WA) wrote: Yes, he did. I remember the article from a long time ago. The theme of the article was how you could improve efficiency by folding the element. It raised the feed impedance and therefore reduced losses. I do not have the article at hand but I do remember it. If it was a QST article then it will be in their online archives. - Wes Attaway (N5WA) --- 1138 Waters Edge Circle, Shreveport, LA 71106 318-797-4972 (Office) - 318-393-3289 (Cell) Computer Consulting and Forensics -- EnCase Certified Examiner --- -Original Message- From: topband-boun...@contesting.com [mailto:topband-boun...@contesting.com] On Behalf Of ZR Sent: Thursday, August 02, 2012 5:58 PM To: Tom W8JI; topband@contesting.com Subject: Re: Topband: THE ITINERANT 160 METER ANTENNA PROJECT - Original Message - From: Tom W8JI w...@w8ji.com To: topband@contesting.com Sent: Thursday, August 02, 2012 6:21 PM Subject: Re: Topband: THE ITINERANT 160 METER ANTENNA PROJECT (1) 130 feet of 300 ohms twin lead with the far one end shorted and pulled up over a coconut by a local climber $5 US max and connected to a small nylon line for adjustment in an inverted or sloping fashion back to my hotel room on the beach. (without the local climber bring along a slingshot fishing line launcher.) If the hotel wasn't right on the beach or had any 70 foot palms I just drove to another one that did. Masting anything up beyond 50 feet by yourself just forget it. Palm trees are great substitutes. I think this antenna was describe for 160 in Bill Orr's (W6SAI) firsts handbooks. Just be aware Orr had a consistent mistake in his articles on folded antennas. He claimed folding reduced ground losses by significant amounts. I'm not sure where that idea started, but using a folded element does not change ground loss one bit. 73 Tom Did he actually claim that or that the effect of the ground loss was reduced? I dont have a reference handy. Carl KM1H - No virus found in this message. Checked by AVG - www.avg.com Version: 2012.0.2197 / Virus Database: 2437/5172 - Release Date: 08/02/12 ___ UR RST IS ... ... ..9 QSB QSB - hw? BK - No virus found in this message. Checked by AVG - www.avg.com Version: 10.0.1424 / Virus Database: 2437/5173 - Release Date: 08/02/12 ___ UR RST IS ... ... ..9 QSB QSB - hw? BK
Re: Topband: THE ITINERANT 160 METER ANTENNA PROJECT
The claim was made in the last several editions of the Radio Handbook in describing a TV twinlead folded Marconi for 160m. I believe the idea was not in QST, because at that time QST had good technical editing. There were very few gross technical gaffs in QST back then. As I recall, the idea originally appeared in either 73 or CQ Magazine. This illustrates the danger of non-peer reviewed technical articles. I personally know of at least a half-dozen AM BC stations that invested money in converting to folded unipoles, and a company in Texas started producing antennas based on that silly idea. http://www.w8ji.com/radiation_resistance.htm 73 Tom ___ UR RST IS ... ... ..9 QSB QSB - hw? BK
Re: Topband: THE ITINERANT 160 METER ANTENNA PROJECT
On 8/3/2012 9:49 AM, Tom W8JI wrote: This illustrates the danger of non-peer reviewed technical articles. I personally know of at least a half-dozen AM BC stations that invested money in converting to folded unipoles, and a company in Texas started producing antennas based on that silly idea. http://www.w8ji.com/radiation_resistance.htm 73 Tom If I appear to be a bit snarky in my rejoinder, nothing personal, its really my style. Both Kintronics and Cortana manufacture kits for AM station and they are they a being used by radio stations all over the world. In can only agree with Tom to the point that what may be silly is any claim that the expectation of converting to a folded unipole by it self increases radiation efficiency was wrong. That notion was dispelled long ago and presented in a paper at the 1996 NAB technical session by a leading broadcast consultant group deTreil, Lundin, and Rackley (www.dlr.com) I did a summary of their study which I posted here in 2003 and back in 2006 (Jan 4, 2006 Top-band: Shunt fed tower question?) I pointed out that the DLR study concluded both by NEC 4.1 analysis and exhaustive field tests on 1600 Khz with an actual tower, with and without being grounded, and with a cage feed did *not* improver FS, radiation efficiency, or exhibit any better performance over a poorer ground system. So why are broadcaster still buying them. Let me try to explain from my marketing and hopefully practical perspective. Today the concept of a folded unipole, once you eschew the original hype and understand the limitations, is far from a silly idea. I think Tom suggests that peer review would have prevented this from happening. Yet the antenna design and continued production of these feed kits appears not to be based on stupidity , but based on a principle that often will trump peer review and that is an idea that has been supported by market forces and a customer base market that pay for it and support it, it will continue beyond negative peer review, and press on regardless. Today with limitation and restrictions on towers more and more facility co location is evident. Having a shirt fed grounded 300 foot tower is a gold mine to broadcasters, especially day timers that could only make a dime when the sun was up. An insulated base AM tower required iso-couplers, some very expensive for high power FM, to take advantage of your real estate. I know of station owners who make today more revenue from cell service, pagers, two way radio, and other stations then they do from their format. its all about location, location, location and if you have one the idea of having a skirt fed antenna is not silly but profitable. Most topbanders know what an the cost of insulated base for a Rohn 45 is and savor the chance to run other feed lines inside the tower for a variety of other antennas, rotor cable, and the like, and how a cage fed tower unipole makes that possible. Such a consideration should also carefully compare the destruction of a lightning strike to associated equipment from a grounded tower to one that is not directly grounded. For sure I know this has nothing to do with E and H plane radiation loses or trying to manipulate Maxwell's equation, but it sure does have something to do with your pocket book when it comes to replacing equipment damaged by a 140 foot free floating lightning rod compared to a grounded lightning dissipation array, if I dare to call my unipole that. Tom was right that the initial 'brag was not peer reviewed and false assumptions were made. Yet the final result over the years a silk purse has been made out of a sows ear contrary to what the old time farmer in Iowa used to tell me. So what have we learned from all of this? Never let peer review get in the way of market forces causing you to throw the baby out with the bathwater. Herb Schoenbohm, KV4FZ ___ UR RST IS ... ... ..9 QSB QSB - hw? BK
Re: Topband: THE ITINERANT 160 METER ANTENNA PROJECT
See, Ham Radio Techniques - 160-Meter Antenna Problems and Solutions, Ham Radio magazine, Pg. 49, March 1990. A 3-wire version is also proposed to increase the radiation resistance by 9x. In the single and multi-wire folded versions the ground loss resistance remained constant. Note that Bill was obtaining his results from the K6STI antenna modeling software he was using. I am not familiar with that program's capabilities or accuracy and it is clear from the article he believed the results he obtained from it. It was the early days of NEC programs for PCs and many of us were just learning how to use and apply the antenna simulation programs. It is impossible to know the basis for his errors in this case. But Bill's contributions to amateur radio were vast and valuable and greatly overshadow this one slip-up. '73, Thomas - ac7a (Tucson) Wes Attaway (N5WA) wesatta...@bellsouth.net wrote: Yes, he did. I remember the article from a long time ago. The theme of the article was how you could improve efficiency by folding the element. It raised the feed impedance and therefore reduced losses. I do not have the article at hand but I do remember it. If it was a QST article then it will be in their online archives. - Wes Attaway (N5WA) --- 1138 Waters Edge Circle, Shreveport, LA 71106 318-797-4972 (Office) - 318-393-3289 (Cell) Computer Consulting and Forensics -- EnCase Certified Examiner --- -Original Message- From: topband-boun...@contesting.com [mailto:topband-boun...@contesting.com] On Behalf Of ZR Sent: Thursday, August 02, 2012 5:58 PM To: Tom W8JI; topband@contesting.com Subject: Re: Topband: THE ITINERANT 160 METER ANTENNA PROJECT - Original Message - From: Tom W8JI w...@w8ji.com To: topband@contesting.com Sent: Thursday, August 02, 2012 6:21 PM Subject: Re: Topband: THE ITINERANT 160 METER ANTENNA PROJECT (1) 130 feet of 300 ohms twin lead with the far one end shorted and pulled up over a coconut by a local climber $5 US max and connected to a small nylon line for adjustment in an inverted or sloping fashion back to my hotel room on the beach. (without the local climber bring along a slingshot fishing line launcher.) If the hotel wasn't right on the beach or had any 70 foot palms I just drove to another one that did. Masting anything up beyond 50 feet by yourself just forget it. Palm trees are great substitutes. I think this antenna was describe for 160 in Bill Orr's (W6SAI) firsts handbooks. Just be aware Orr had a consistent mistake in his articles on folded antennas. He claimed folding reduced ground losses by significant amounts. I'm not sure where that idea started, but using a folded element does not change ground loss one bit. 73 Tom Did he actually claim that or that the effect of the ground loss was reduced? I dont have a reference handy. Carl KM1H ___ UR RST IS ... ... ..9 QSB QSB - hw? BK - No virus found in this message. Checked by AVG - www.avg.com Version: 10.0.1424 / Virus Database: 2437/5173 - Release Date: 08/02/12 ___ UR RST IS ... ... ..9 QSB QSB - hw? BK ___ UR RST IS ... ... ..9 QSB QSB - hw? BK ___ UR RST IS ... ... ..9 QSB QSB - hw? BK
Re: Topband: THE ITINERANT 160 METER ANTENNA PROJECT
Note that Bill was obtaining his results from the K6STI antenna modeling software he was using. I am not familiar with that program's capabilities or accuracy and it is clear from the article he believed the results he obtained from it. Bill simply did not understand the difference between antenna feed impedance and radiation resistance. A folded dipole or folded unipole is no different than a conventional radiator with an N:1 UN-UN or balun between the feedline and antenna terminals. The matching device (balun, un-un, L-network, pi-network, hairpin, beta match, etc.) transforms the sum of the radiation resistance *and* loss resistance equally. But Bill's contributions to amateur radio were vast and valuable and greatly overshadow this one slip-up. This is far from Bill's only slip-up - his bully-like advocacy of floating grids in grounded grid amplifiers is another case of non- science. 73, ... Joe, W4TV On 8/3/2012 11:23 AM, Thomas wrote: See, Ham Radio Techniques - 160-Meter Antenna Problems and Solutions, Ham Radio magazine, Pg. 49, March 1990. A 3-wire version is also proposed to increase the radiation resistance by 9x. In the single and multi-wire folded versions the ground loss resistance remained constant. Note that Bill was obtaining his results from the K6STI antenna modeling software he was using. I am not familiar with that program's capabilities or accuracy and it is clear from the article he believed the results he obtained from it. It was the early days of NEC programs for PCs and many of us were just learning how to use and apply the antenna simulation programs. It is impossible to know the basis for his errors in this case. But Bill's contributions to amateur radio were vast and valuable and greatly overshadow this one slip-up. '73, Thomas - ac7a (Tucson) Wes Attaway (N5WA) wesatta...@bellsouth.net wrote: Yes, he did. I remember the article from a long time ago. The theme of the article was how you could improve efficiency by folding the element. It raised the feed impedance and therefore reduced losses. I do not have the article at hand but I do remember it. If it was a QST article then it will be in their online archives. - Wes Attaway (N5WA) --- 1138 Waters Edge Circle, Shreveport, LA 71106 318-797-4972 (Office) - 318-393-3289 (Cell) Computer Consulting and Forensics -- EnCase Certified Examiner --- -Original Message- From: topband-boun...@contesting.com [mailto:topband-boun...@contesting.com] On Behalf Of ZR Sent: Thursday, August 02, 2012 5:58 PM To: Tom W8JI; topband@contesting.com Subject: Re: Topband: THE ITINERANT 160 METER ANTENNA PROJECT - Original Message - From: Tom W8JI w...@w8ji.com To: topband@contesting.com Sent: Thursday, August 02, 2012 6:21 PM Subject: Re: Topband: THE ITINERANT 160 METER ANTENNA PROJECT (1) 130 feet of 300 ohms twin lead with the far one end shorted and pulled up over a coconut by a local climber $5 US max and connected to a small nylon line for adjustment in an inverted or sloping fashion back to my hotel room on the beach. (without the local climber bring along a slingshot fishing line launcher.) If the hotel wasn't right on the beach or had any 70 foot palms I just drove to another one that did. Masting anything up beyond 50 feet by yourself just forget it. Palm trees are great substitutes. I think this antenna was describe for 160 in Bill Orr's (W6SAI) firsts handbooks. Just be aware Orr had a consistent mistake in his articles on folded antennas. He claimed folding reduced ground losses by significant amounts. I'm not sure where that idea started, but using a folded element does not change ground loss one bit. 73 Tom Did he actually claim that or that the effect of the ground loss was reduced? I dont have a reference handy. Carl KM1H ___ UR RST IS ... ... ..9 QSB QSB - hw? BK - No virus found in this message. Checked by AVG - www.avg.com Version: 10.0.1424 / Virus Database: 2437/5173 - Release Date: 08/02/12 ___ UR RST IS ... ... ..9 QSB QSB - hw? BK ___ UR RST IS ... ... ..9 QSB QSB - hw? BK ___ UR RST IS ... ... ..9 QSB QSB - hw? BK ___ UR RST IS ... ... ..9 QSB QSB - hw? BK
Re: Topband: THE ITINERANT 160 METER ANTENNA PROJECT
Well said, in every respect, Tom. 73, Jim K9YC On 8/3/2012 10:07 AM, Tom W8JI wrote: I don't think any anyone with an experimentation (Edisonian), engineering, or science background would assume a few errors (or even a few dozen errors) automatically means we can't trust anything an author says, or assume value of overall contributions are diminished from a few mistakes, or even several mistakes. That's more what those who think in terms of everything being either all correct or all wrong, do. That's for religion or politics, not science. We should be able to freely discuss and correct errors in a nice non-personal way, and not assume pointing out an error is the same as insulting someone's mother, sister, character, or value. Books and publications without proper technical review process and error correction are the real problem, not the overall value of the overall contribution. The ARRL Handbooks have very few mistakes because they have a good review process. Not because of any difference in author quality. The review process is key. ___ UR RST IS ... ... ..9 QSB QSB - hw? BK
Re: Topband: THE ITINERANT 160 METER ANTENNA PROJECT
I have been clobbered every time I mention this. Is there some one other than me that knows the following I had read in a Hand Book for the 1930's the 3 wire folded dipole and 2 wire folded dipole had a couple factor of 1. This would make this antenna the preferred driven element for a long yagi. Folded dipoles are all so used when installations require long lengths of feed line. Back when the Bazooka or Double Bazooka or other wise now known as coaxial antenna back around 1970 I think when I saw it in Ham Radio Mag.. Its coupling factor was around 0.9 No some had told me that later on the coupling fact was really Velocity Factor. Now how can the velocity factor gets interpreted as to how well a driven element couples when compared to gamma match elements or Dipole or a folded dipole or bazooka? See, Ham Radio Techniques - 160-Meter Antenna Problems and Solutions, Ham Radio magazine, Pg. 49, March 1990. A 3-wire version is also proposed to increase the radiation resistance by 9x. In the single and multi-wire folded versions the ground loss resistance remained constant. Note that Bill was obtaining his results from the K6STI antenna modeling software he was using. I am not familiar with that program's capabilities or accuracy and it is clear from the article he believed the results he obtained from it. It was the early days of NEC programs for PCs and many of us were just learning how to use and apply the antenna simulation programs. It is impossible to know the basis for his errors in this case. But Bill's contributions to amateur radio were vast and valuable and greatly overshadow this one slip-up. '73, Thomas - ac7a (Tucson) - Stay on course, fight a good fight, and keep the faith. Jim K9TF/WA9YSD ___ UR RST IS ... ... ..9 QSB QSB - hw? BK
Re: Topband: THE ITINERANT 160 METER ANTENNA PROJECT
Just to make certain that we're on the same page, I'm writing of the Radio Handbook, the one Bill Orr edited. It was a Radio Magazine handbook, perhaps later CQ Magazine and finally published by Sams. That was the one filled with linear amplifier articles for both HF and VHF. I think more of Bill's articles appeared in CQ than QST. 73, Dave K8MN On 8/3/2012 13 49, Tom W8JI wrote: The claim was made in the last several editions of the Radio Handbook in describing a TV twinlead folded Marconi for 160m. I believe the idea was not in QST, because at that time QST had good technical editing. There were very few gross technical gaffs in QST back then. As I recall, the idea originally appeared in either 73 or CQ Magazine. This illustrates the danger of non-peer reviewed technical articles. I personally know of at least a half-dozen AM BC stations that invested money in converting to folded unipoles, and a company in Texas started producing antennas based on that silly idea. http://www.w8ji.com/radiation_resistance.htm 73 Tom ___ UR RST IS ... ... ..9 QSB QSB - hw? BK - No virus found in this message. Checked by AVG - www.avg.com Version: 2012.0.2197 / Virus Database: 2437/5174 - Release Date: 08/03/12 - No virus found in this message. Checked by AVG - www.avg.com Version: 2012.0.2197 / Virus Database: 2437/5174 - Release Date: 08/03/12 ___ UR RST IS ... ... ..9 QSB QSB - hw? BK
Re: Topband: THE ITINERANT 160 METER ANTENNA PROJECT
On Lord Howe Island last summer, on 160M, we deployed a Spiderbeam 18M fiberglass telescopic pole with a 1/4 wave wire taped to it. The excess wire came off the top like an inverted L and was tied to a convenient fence. There were two sets of 4 light synthetic rope guys to ground stakes. We had a bunch of radials made of electric fence wire on the ground and a small matching network at the base. Light, easy to erect, shippable, not too expensive and worked very well. I believe we will have the same antenna on Campbell Island in November. No engineering required except for the matching network. Les W2LK On 7/30/2012 8:32 PM, bills stuff wrote: The plan is to develop a simple, relatively inexpensive, relatively light weight and shippable/airline transportable 160 antenna kit for one man quick deployment for modest DXpeditions or contributed for use by resident hams in rare-ish (for 160 m) locations.The ability to make adjustments to actual deployments to provide matching is important since such antennas are famously variable due to soil and local obstruction environment and there should not be a need for antenna matching hardware, especially at the planned higher powers. First cut electrical design:Inverted L using telescoping aluminum tubes, two elevated radials and hairpin matching. Mechanical features of a prototype that was deployed: 9 Alum tubes 6', .058 walls, 2 diameter through 1 diameter -- this gives a 50' or 15.3 m mast (it can be pulled upright by 1 person, or probably telescoped up also) #14 wire ~ 28 m for top wire and 2X ~34 m radials (values after some adjustment, not unique, some tradeoff between the top and radials) Base - 2 thicknesses of Walmart (cheap 8X11) ¼ plastic cutting board resting on ground with a ~ 1.5 wood cylinder bolted in the center.SO-239 connector screwed to the board. Guys -- 4X 3/32 dacron rope attached at 7 tube height, angled at ~ 45deg Guys held down by sandbags (very effective and moveable) Inv L top wire end was at ~ 2.5 m height with a support of opportunity (e.g., a tree) ~ 25 m from base Radials have their closest support near the base from plastic rings looped through each of an opposite pair of the guys at ~ 6 m high and 6 m from the mast.The radials therefore go from the base to the rings at about a 45 degree angle.(Elevating the base and everything else, by a meter did not seem to affect the impedance.Beyond that, supports of opportunity were used - above neck height is always nice. This produces, with some fiddling with wire lengths, an impedance around 20 -- j20 which can be matched using a practical hairpin coil shunt of inductive reactance ~ 45 ohms ( 4 microHenrys, say 5 turns 4 dia). More details of the test case including the EZNEC example are shown on my website.There are obviously a number of ways this design could be modified/improved, several discussed on the website.However, the tradeoffs with size, weight and complexity must be considered in the light of the mission here which includes transportability and ease of deployment. I am looking for collaborators to contribute ideas to help improve, and potentially, test design issues.Check out the website at http://n6mw.ehpes.com http://n6mw.ehpes.com/ for the Itinerant 160 m antenna project expanded discussion toward the bottom. The immediate target is designing and assembling a respectable 160 m antenna that might go to KH8 on a DXpedition. Bill, N6MW billsstuff(at)gotsky.com ___ UR RST IS ... ... ..9 QSB QSB - hw? BK ___ UR RST IS ... ... ..9 QSB QSB - hw? BK
Re: Topband: THE ITINERANT 160 METER ANTENNA PROJECT
On 7/30/2012 8:32 PM, bills stuff wrote: The plan is to develop a simple, relatively inexpensive, relatively light weight and shippable/airline transportable 160 antenna kit for one man quick deployment for modest DXpeditions or contributed for use by resident hams in rare-ish (for 160 m) locations.The ability to make adjustments to actual deployments to provide matching is important since such antennas are famously variable due to soil and local obstruction environment and there should not be a need for antenna matching hardware, especially at the planned higher powers. I think I had perhaps one of the simplest and most effective 160 meter antennas for an island hoping DX-pedition through the parts the Caribbean islands and SA in the 60's. Here is what I used with a 100 watt rig and was thrilled at the performance. (1) 130 feet of 300 ohms twin lead with the far one end shorted and pulled up over a coconut by a local climber $5 US max and connected to a small nylon line for adjustment in an inverted or sloping fashion back to my hotel room on the beach. (without the local climber bring along a slingshot fishing line launcher.) If the hotel wasn't right on the beach or had any 70 foot palms I just drove to another one that did. Masting anything up beyond 50 feet by yourself just forget it. Palm trees are great substitutes. I think this antenna was describe for 160 in Bill Orr's (W6SAI) firsts handbooks. (2) Since most resorts had copper water piping (now it is almost all PVC) that provided the ground connection or a lightweight run of RG-59 went to the twin lead connected by one side to a ground stake and the other to the hot side. (3) Today's rigs with auto tuners should have no problem in feeding this set up. Back there was no internet, DSL's, routers and modems. Today things are different a longer coax (RG-8x) may be advisable in getting this away from the noise sources. My radio for top band back then were a pair of Drake Twins and with today's radios ad switching supplies all of this could fit in a carry one with room to spare for a laptop for logging and some a 500 wire rolls for a Beverage. If you can't get up a Beverage tie some of the wire on rocks and pitch them into the waters to enhance your ground connection or just run out some radials under the sand. I think the point I am trying to make is that if you have a good DX-pedition QTH picked out in advance which you can even Google Earth as needed, this idea would work well. However, if you don't end up in a good location there isn't anything that you could carry along on a plane that would change much of this unless you are willing to pay huge cargo and brokerage charges. Herb Schoenbohm, KV4FZ ___ UR RST IS ... ... ..9 QSB QSB - hw? BK
Re: Topband: THE ITINERANT 160 METER ANTENNA PROJECT
(1) 130 feet of 300 ohms twin lead with the far one end shorted and pulled up over a coconut by a local climber $5 US max and connected to a small nylon line for adjustment in an inverted or sloping fashion back to my hotel room on the beach. (without the local climber bring along a slingshot fishing line launcher.) If the hotel wasn't right on the beach or had any 70 foot palms I just drove to another one that did. Masting anything up beyond 50 feet by yourself just forget it. Palm trees are great substitutes. I think this antenna was describe for 160 in Bill Orr's (W6SAI) firsts handbooks. Just be aware Orr had a consistent mistake in his articles on folded antennas. He claimed folding reduced ground losses by significant amounts. I'm not sure where that idea started, but using a folded element does not change ground loss one bit. 73 Tom ___ UR RST IS ... ... ..9 QSB QSB - hw? BK
Re: Topband: THE ITINERANT 160 METER ANTENNA PROJECT
Agreed Tom. I just followed the conventional wisdom of the time and it did seem easier to match than a single wire. At least it made me feel that it did. Herb, KV4FZ On 8/2/2012 6:21 PM, Tom W8JI wrote: (1) 130 feet of 300 ohms twin lead with the far one end shorted and pulled up over a coconut by a local climber $5 US max and connected to a small nylon line for adjustment in an inverted or sloping fashion back to my hotel room on the beach. (without the local climber bring along a slingshot fishing line launcher.) If the hotel wasn't right on the beach or had any 70 foot palms I just drove to another one that did. Masting anything up beyond 50 feet by yourself just forget it. Palm trees are great substitutes. I think this antenna was describe for 160 in Bill Orr's (W6SAI) firsts handbooks. Just be aware Orr had a consistent mistake in his articles on folded antennas. He claimed folding reduced ground losses by significant amounts. I'm not sure where that idea started, but using a folded element does not change ground loss one bit. 73 Tom ___ UR RST IS ... ... ..9 QSB QSB - hw? BK ___ UR RST IS ... ... ..9 QSB QSB - hw? BK
Re: Topband: THE ITINERANT 160 METER ANTENNA PROJECT
Yes, he did. I remember the article from a long time ago. The theme of the article was how you could improve efficiency by folding the element. It raised the feed impedance and therefore reduced losses. I do not have the article at hand but I do remember it. If it was a QST article then it will be in their online archives. - Wes Attaway (N5WA) --- 1138 Waters Edge Circle, Shreveport, LA 71106 318-797-4972 (Office) - 318-393-3289 (Cell) Computer Consulting and Forensics -- EnCase Certified Examiner --- -Original Message- From: topband-boun...@contesting.com [mailto:topband-boun...@contesting.com] On Behalf Of ZR Sent: Thursday, August 02, 2012 5:58 PM To: Tom W8JI; topband@contesting.com Subject: Re: Topband: THE ITINERANT 160 METER ANTENNA PROJECT - Original Message - From: Tom W8JI w...@w8ji.com To: topband@contesting.com Sent: Thursday, August 02, 2012 6:21 PM Subject: Re: Topband: THE ITINERANT 160 METER ANTENNA PROJECT (1) 130 feet of 300 ohms twin lead with the far one end shorted and pulled up over a coconut by a local climber $5 US max and connected to a small nylon line for adjustment in an inverted or sloping fashion back to my hotel room on the beach. (without the local climber bring along a slingshot fishing line launcher.) If the hotel wasn't right on the beach or had any 70 foot palms I just drove to another one that did. Masting anything up beyond 50 feet by yourself just forget it. Palm trees are great substitutes. I think this antenna was describe for 160 in Bill Orr's (W6SAI) firsts handbooks. Just be aware Orr had a consistent mistake in his articles on folded antennas. He claimed folding reduced ground losses by significant amounts. I'm not sure where that idea started, but using a folded element does not change ground loss one bit. 73 Tom Did he actually claim that or that the effect of the ground loss was reduced? I dont have a reference handy. Carl KM1H ___ UR RST IS ... ... ..9 QSB QSB - hw? BK - No virus found in this message. Checked by AVG - www.avg.com Version: 10.0.1424 / Virus Database: 2437/5173 - Release Date: 08/02/12 ___ UR RST IS ... ... ..9 QSB QSB - hw? BK ___ UR RST IS ... ... ..9 QSB QSB - hw? BK
Topband: THE ITINERANT 160 METER ANTENNA PROJECT
The plan is to develop a simple, relatively inexpensive, relatively light weight and shippable/airline transportable 160 antenna kit for one man quick deployment for modest DXpeditions or contributed for use by resident hams in rare-ish (for 160 m) locations.The ability to make adjustments to actual deployments to provide matching is important since such antennas are famously variable due to soil and local obstruction environment and there should not be a need for antenna matching hardware, especially at the planned higher powers. First cut electrical design:Inverted L using telescoping aluminum tubes, two elevated radials and hairpin matching. Mechanical features of a prototype that was deployed: 9 Alum tubes 6', .058 walls, 2 diameter through 1 diameter -- this gives a 50' or 15.3 m mast (it can be pulled upright by 1 person, or probably telescoped up also) #14 wire ~ 28 m for top wire and 2X ~34 m radials (values after some adjustment, not unique, some tradeoff between the top and radials) Base - 2 thicknesses of Walmart (cheap 8X11) ¼ plastic cutting board resting on ground with a ~ 1.5 wood cylinder bolted in the center.SO-239 connector screwed to the board. Guys -- 4X 3/32 dacron rope attached at 7 tube height, angled at ~ 45deg Guys held down by sandbags (very effective and moveable) Inv L top wire end was at ~ 2.5 m height with a support of opportunity (e.g., a tree) ~ 25 m from base Radials have their closest support near the base from plastic rings looped through each of an opposite pair of the guys at ~ 6 m high and 6 m from the mast.The radials therefore go from the base to the rings at about a 45 degree angle.(Elevating the base and everything else, by a meter did not seem to affect the impedance.Beyond that, supports of opportunity were used - above neck height is always nice. This produces, with some fiddling with wire lengths, an impedance around 20 -- j20 which can be matched using a practical hairpin coil shunt of inductive reactance ~ 45 ohms ( 4 microHenrys, say 5 turns 4 dia). More details of the test case including the EZNEC example are shown on my website.There are obviously a number of ways this design could be modified/improved, several discussed on the website.However, the tradeoffs with size, weight and complexity must be considered in the light of the mission here which includes transportability and ease of deployment. I am looking for collaborators to contribute ideas to help improve, and potentially, test design issues.Check out the website at http://n6mw.ehpes.com http://n6mw.ehpes.com/ for the Itinerant 160 m antenna project expanded discussion toward the bottom. The immediate target is designing and assembling a respectable 160 m antenna that might go to KH8 on a DXpedition. Bill, N6MW billsstuff(at)gotsky.com ___ UR RST IS ... ... ..9 QSB QSB - hw? BK
Re: Topband: THE ITINERANT 160 METER ANTENNA PROJECT
Why an L versus a T, with the T's arms over the radials depending upon wind direction? Just curious. Not questioning the design. KH8, some days we can almost see it from Alaska. GL and keep dreaming, we'll be looking for a contact. 73, Gary NL7Y ___ UR RST IS ... ... ..9 QSB QSB - hw? BK
