Topband: the other inverted L
in my simplistic way of settting up an antenna, link coupling a tank circuit, the top of which is connected to a half wave long inverted L, the bottom of which (right now) is connected to a 5/16 wave FCP I know what power goes out of the top of the coil must come into the bottom of the coil somehow. I have done all I can do to get the current portion of the antenna as far up and away from the ground that I can To avoid the FCP ground counterpoise problem altogether, I could center feed the L with coax to a link on the tank or up the turns on the link and feed it as an OCF dipole half way up the vertical leg. now no ground return is necessary on the tank curcuit I am not saying that if I had a perfect ground screen below the antenna that "that would not be a good thing to do" mike w7dra 53 Year Old Mom Looks 33 The Stunning Results of Her Wrinkle Trick Has Botox Doctors Worried http://thirdpartyoffers.juno.com/TGL3141/501cc3369de6343361d17st04vuc ___ UR RST IS ... ... ..9 QSB QSB - hw? BK
Re: Topband: ITINERANT 160 M ANTENNA - Response Summary
Well said. - 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 Tom W8JI Sent: Friday, August 03, 2012 8:49 PM To: bills stuff; topband@contesting.com Subject: Re: Topband: ITINERANT 160 M ANTENNA - Response Summary So gently getting back to the topic of the original post which was: Getting thoughts on relatively simple and relatively inexpensive portable 160 m antenna, potentially deployable by one person, that allows for flexibility and somewhat predictable tuning for use on modest Dxpeds or rare location indigenous ops.>>> Asking for the best antenna is like asking someone else to pick out a bride. All you can do is say a few universal things to look out for. It's almost impossible to tell someone what specific system would be best. Most of the differences are related to physical restrictions, unless something electrically important is done incorrectly. Most of the things we argue endlessly about, or work tirelessly on, are really for fractions of a dB or personal taste. 1.) If you use a small counterpoise, don't ground it with RF paths. Isolate the feedline from the counterpoise and isolate the counterpoise from earth. 2.) Don't fold back antennas in high current areas, because current causes EM radiation. Keep the high current area straight and as long as possible. 3.) Use the largest counterpoise possible, and use one that does not concentrate current, zig-zag current all around, or produce unnecessarily high voltages. 4.) Build something that you can install, and that will stay up. 5.) Most of all, pick the best location you can. ___ UR RST IS ... ... ..9 QSB QSB - hw? BK ___ UR RST IS ... ... ..9 QSB QSB - hw? BK
Topband: T2FD Antennas
While I was selling, designing and installing Military, Embassy and Coastal Radio Station upgrades and new installations all over Asia and their counterparts around the world I was amazed how many B&W Folded Dipoles were specified in tenders, solicitations and requirement documents. I sold hundreds of them, the customer received what the customer wants and paid for. -Original Message- From: topband-boun...@contesting.com [mailto:topband-boun...@contesting.com] On Behalf Of Herb Schoenbohm Sent: Friday, August 03, 2012 11:30 AM To: topband@contesting.com Subject: Re: Topband: Antennas Price, The Military and U.S. Embassies use T2FD type of antennas all over their deployment perhaps due to the fact that they do work as long as you have plenty of horsepower to feed them with. I think the requirement of frequency agility for their requirement outweighs the inherent inefficiency. If you don't mind putting a "radiating dummy load" in the air then perhaps it is not such a bad idea. The design is still part of the military nomenclature with an ANN number and their is one on the VI national Guard building a few blocks from my office. It is hooked to a 10KW Harris 2-30 Mhz box to connect to FEMA Region 2 on a multitude of frequencies driving by the propagation at the moment. The T2FD mil spec version is supposed to be rugged enough to work through and survive a Cat 4 hurricane. None of my antennas nor towers could make that claim. Herb Schoenbohm, KV4FZ On 8/3/2012 10:21 AM, HAROLD SMITH JR wrote: > Hi Tom, > > I am suprised that no one has brought up the "T2FD" antenna and > of course the B&W "All-Band" antenna. > > It was in one of the magazines back in the (50s?). > > 73 > Price W0RI > ___ > 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: ITINERANT 160 M ANTENNA - Response Summary
So gently getting back to the topic of the original post which was: Getting thoughts on relatively simple and relatively inexpensive portable 160 m antenna, potentially deployable by one person, that allows for flexibility and somewhat predictable tuning for use on modest Dxpeds or rare location indigenous ops.>>> Asking for the best antenna is like asking someone else to pick out a bride. All you can do is say a few universal things to look out for. It's almost impossible to tell someone what specific system would be best. Most of the differences are related to physical restrictions, unless something electrically important is done incorrectly. Most of the things we argue endlessly about, or work tirelessly on, are really for fractions of a dB or personal taste. 1.) If you use a small counterpoise, don't ground it with RF paths. Isolate the feedline from the counterpoise and isolate the counterpoise from earth. 2.) Don't fold back antennas in high current areas, because current causes EM radiation. Keep the high current area straight and as long as possible. 3.) Use the largest counterpoise possible, and use one that does not concentrate current, zig-zag current all around, or produce unnecessarily high voltages. 4.) Build something that you can install, and that will stay up. 5.) Most of all, pick the best location you can. ___ UR RST IS ... ... ..9 QSB QSB - hw? BK
Re: Topband: opinion
Mais avec les femmes vous ne jamais leur dire qu'ils sont en train de changer mais oui - Original Message - From: "Kenneth Grimm" To: "Herb Schoenbohm" Cc: ; "Bruce" Sent: Friday, August 03, 2012 3:56 PM Subject: Re: Topband: opinion Plus ça change, plus c'est la même chose 73, Ken - K4XL On Fri, Aug 3, 2012 at 1:59 PM, Herb Schoenbohm wrote: > The problem was that the Ptolemyic concept of a Geo- Centric universe > worked for some basic navigational functions, was universally excepted > and became part of religious doctrine. Anyone who promoted "truth" of > a HelioCentric Universe whether it was Galileo, Copernicus and even > later Kepler were condemmed by the chruch. It was the decision of > theologians or the state or the church state that called the shots on > science. What this did was suppressed advances for a while. Even today > we have the impact in our economic survival due to the doxology of > AlGore on "climate change" or man-made climate change. Dr. Edward Gray > from Bolder was essential drummed out of the very accurate Univ. of > Colorado hurricane prediction service for even questioning the new > theology of a political control over climate and people as having any > significant merit, except for the empowerment of politicians who are > engaged in dogma. Why is it always the contrarian views always get in > the way of new ideas and punish those who express them. > > Herb Schoenbohm, KV4FZ > > > > > On 8/3/2012 3:26 PM, Bruce wrote: > > It's a balance. Even a correct new idea sometimes takes it "in the > neck" so to speak. Think of all the crap the first guy took from those > that said the sun was circling the earth. After all you could see it for > half of the circle. > > > > We have to believe what we know is correct, but have an open mind to new > ideas. > > > > 73 > > Bruce > > ___ > > UR RST IS ... ... ..9 QSB QSB - hw? BK > > ___ > UR RST IS ... ... ..9 QSB QSB - hw? BK > -- Ken - K4XL BoatAnchor Manual Archive BAMA - http://bama.edebris.com ___ 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: 2437/5174 - Release Date: 08/03/12 ___ UR RST IS ... ... ..9 QSB QSB - hw? BK
Re: Topband: ITINERANT 160 M ANTENNA - Response Summary
If youre stuck with on ground radials figure you wont have room for full size. In that case see if 50'x 2' rolls of galvanized chicken wire is available locally. Put out 4 rolls as spokes and wire together at the far ends and at the antenna base. Also solder the points where they start to overlap and several more places. The idea is to create an as complete ground screen as you have time for. If there is close salt water run some bare copper wire into it from the screen ends; lead fishing sinkers work well to keep them in place. Carl KM1H - Original Message - From: "bills stuff" To: Sent: Friday, August 03, 2012 3:44 PM Subject: Topband: ITINERANT 160 M ANTENNA - Response Summary So gently getting back to the topic of the original post which was: Getting thoughts on relatively simple and relatively inexpensive portable 160 m antenna, potentially deployable by one person, that allows for flexibility and somewhat predictable tuning for use on modest Dxpeds or rare location indigenous ops. Strawman proposal was for Inv L 50’(or more) alum mast with elevated radials all tuned with “hairpin” shunt coil – plus a request for suggestions and potential actual physical assistance with testing/assembly/distribution. Principal thoughts to date by TB types posted and direct: 1. More top wires than just one – doable with minimum additions provided the site has space. Should improve performance somewhat, requires top wire supports in other directions (which may only be a minor issue) and some more wire. 2. Mast higher than 50’ - I believe at 55’ (~17 m) it is still quite possible to hoist it up (maybe not walk up but a rope attached 1/3+ of the way up) 3. Use 18 m fiberglass telescope instead of alum. - Doable and can be walked up they say, but nearly twice as heavy as alum, more expensive and bending at top reduces effective height a bit. But still if you’ve got one . . . 4. Ground radials instead of elevated. - Could be good for some locations but requires 20+ m radius circle thick with wires. The innkeeper might not be pleased and also space may not be available unless you go the tent/generator route. I suppose the antenna product could be in two flavors, ground and elevated, with possible different tuning of the top wire. 5. Go to a site that has nicely spaced high palm trees (on the good propagation side of course) and then . . . - I welcome volunteer advanced palm tree scouts. Yet perhaps not all (or even most) interesting 160 m entities have palm trees. - Yet the point is well taken that a good site with advanced planning (Google Earth/eyeballs) is important (when possible). This matter has been looked at for KH8 but I am looking at broader uses as well. 6. Matching not worth the effort with modern ATUs - Yes but I would not think of trying a semi-serious 160 m effort with low power (or difficult to match antenna), and the high power matching units have $, size and weight issues. The current plan has the charm of a simple, flexible matching coil even at the expense of tuning by fiddling with top wire and/or elevated radial lengths 7. Receive antenna use - I purposely did not mention this just to see if it would be seen as an oversight among TBers. My only personal experience is I don’t have one and there have been a significant number of high end 160 stations (who surely have Rx ants) I could hear but could not hear me (my ant is a bit better than the one proposed here and with 500 w). Of course, his story may not hold up for a rare-ish DX station. Anything else? Bill N6MW ___ 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: 2437/5174 - Release Date: 08/03/12 ___ 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
Topband: opinion
Herb, My mistake about the posting censor. I had the topband address incorrect. Maybe had too many days hiking up on the mountain installing the new FM radio station transmitter this week. Sorry Tree 73 Bruce ___ UR RST IS ... ... ..9 QSB QSB - hw? BK
Re: Topband: opinion
Is this a current Topband topic? Did I miss something. I thought folks were talking about antennas and some new and unusual ideas with respect to them. Tod, K0TO >Even today >we have the impact in our economic survival due to the doxology of >AlGore on "climate change" or man-made climate change. Dr. Edward Gray >from Bolder was essential drummed out of the very accurate Univ. of >Colorado hurricane prediction service for even questioning the new >theology of a political control over climate and people as having any >significant merit, except for the empowerment of politicians who are >engaged in dogma. Why is it always the contrarian views always get in >the way of new ideas and punish those who express them. ___ UR RST IS ... ... ..9 QSB QSB - hw? BK
Re: Topband: opinion
Plus ça change, plus c'est la même chose 73, Ken - K4XL On Fri, Aug 3, 2012 at 1:59 PM, Herb Schoenbohm wrote: > The problem was that the Ptolemyic concept of a Geo- Centric universe > worked for some basic navigational functions, was universally excepted > and became part of religious doctrine. Anyone who promoted "truth" of > a HelioCentric Universe whether it was Galileo, Copernicus and even > later Kepler were condemmed by the chruch. It was the decision of > theologians or the state or the church state that called the shots on > science. What this did was suppressed advances for a while. Even today > we have the impact in our economic survival due to the doxology of > AlGore on "climate change" or man-made climate change. Dr. Edward Gray > from Bolder was essential drummed out of the very accurate Univ. of > Colorado hurricane prediction service for even questioning the new > theology of a political control over climate and people as having any > significant merit, except for the empowerment of politicians who are > engaged in dogma. Why is it always the contrarian views always get in > the way of new ideas and punish those who express them. > > Herb Schoenbohm, KV4FZ > > > > > On 8/3/2012 3:26 PM, Bruce wrote: > > It's a balance. Even a correct new idea sometimes takes it "in the > neck" so to speak. Think of all the crap the first guy took from those > that said the sun was circling the earth. After all you could see it for > half of the circle. > > > > We have to believe what we know is correct, but have an open mind to new > ideas. > > > > 73 > > Bruce > > ___ > > UR RST IS ... ... ..9 QSB QSB - hw? BK > > ___ > UR RST IS ... ... ..9 QSB QSB - hw? BK > -- Ken - K4XL BoatAnchor Manual Archive BAMA - http://bama.edebris.com ___ UR RST IS ... ... ..9 QSB QSB - hw? BK
Topband: ITINERANT 160 M ANTENNA - Response Summary
So gently getting back to the topic of the original post which was: Getting thoughts on relatively simple and relatively inexpensive portable 160 m antenna, potentially deployable by one person, that allows for flexibility and somewhat predictable tuning for use on modest Dxpeds or rare location indigenous ops. Strawman proposal was for Inv L 50’(or more) alum mast with elevated radials all tuned with “hairpin” shunt coil – plus a request for suggestions and potential actual physical assistance with testing/assembly/distribution. Principal thoughts to date by TB types posted and direct: 1. More top wires than just one – doable with minimum additions provided the site has space. Should improve performance somewhat, requires top wire supports in other directions (which may only be a minor issue) and some more wire. 2. Mast higher than 50’ - I believe at 55’ (~17 m) it is still quite possible to hoist it up (maybe not walk up but a rope attached 1/3+ of the way up) 3. Use 18 m fiberglass telescope instead of alum. - Doable and can be walked up they say, but nearly twice as heavy as alum, more expensive and bending at top reduces effective height a bit. But still if you’ve got one . . . 4. Ground radials instead of elevated. - Could be good for some locations but requires 20+ m radius circle thick with wires. The innkeeper might not be pleased and also space may not be available unless you go the tent/generator route. I suppose the antenna product could be in two flavors, ground and elevated, with possible different tuning of the top wire. 5. Go to a site that has nicely spaced high palm trees (on the good propagation side of course) and then . . . - I welcome volunteer advanced palm tree scouts. Yet perhaps not all (or even most) interesting 160 m entities have palm trees. - Yet the point is well taken that a good site with advanced planning (Google Earth/eyeballs) is important (when possible). This matter has been looked at for KH8 but I am looking at broader uses as well. 6. Matching not worth the effort with modern ATUs - Yes but I would not think of trying a semi-serious 160 m effort with low power (or difficult to match antenna), and the high power matching units have $, size and weight issues. The current plan has the charm of a simple, flexible matching coil even at the expense of tuning by fiddling with top wire and/or elevated radial lengths 7. Receive antenna use - I purposely did not mention this just to see if it would be seen as an oversight among TBers. My only personal experience is I don’t have one and there have been a significant number of high end 160 stations (who surely have Rx ants) I could hear but could not hear me (my ant is a bit better than the one proposed here and with 500 w). Of course, his story may not hold up for a rare-ish DX station. Anything else? Bill N6MW ___ UR RST IS ... ... ..9 QSB QSB - hw? BK
Re: Topband: Antennas
>> The so called T2FD's sold these days by the usual ham dealer suspects is >> nowhere near the original design so its no stretch as to why its not a >> great >> performer. Any antenna that increases bandwidth through a resistive termination will always lose a substantial portion of power as heat on bands where the resistive termination is correcting mismatches. There is no way around that problem, no matter what spacing or tilt is used. Loss varies a great deal with frequency, but loss is the mechanism that corrects match on high SWR bands. No matter what exact T2FD design, loss (efficiency) varies significantly with frequency and some frequencies will be pretty sour. The nice thing is almost anything can work DX when conditions are good. 73 Tom ___ UR RST IS ... ... ..9 QSB QSB - hw? BK
Re: Topband: Antennas
EDIT: change the second paragraph to: Included are results reported by the USN, who did the design, in multiple comparisons to existing antennas at many locations as well as detailed construction details. Wire spacing and resistor value combined with feedline impedance is critical. The tilt angle is less critical and can be 20-40 degrees. Carl KM1H - Original Message - From: "ZR" To: "Herb Schoenbohm" ; Sent: Friday, August 03, 2012 12:27 PM Subject: Re: Topband: Antennas > The T2FD was described in QST for June 1949 and CQ for November 1951 and > February 1953, all by USN Capt G.L. Countryman, W3HH. > > Included are results reported by the USN, who did the design, in > comparison > to existing antennas as well as detailed construction details. Wire > spacing > and tilt angle are critical. > > Ive had one up for several years primarily as a SWL antenna for a couple > of > boatanchor receivers using a 10W resistor and have also made numerous > 10-40W > contacts with it without difficulty 80-17M. Ive no comparison wire > antennas > at similar heights so no performance claims are being made other than that > I > can work DX and domestic stations with it. > > The so called T2FD's sold these days by the usual ham dealer suspects is > nowhere near the original design so its no stretch as to why its not a > great > performer. > > Others just give it a thumbs down without ever trying it and just waste a > lot of others time with their views. > > Carl > KM1H > > > > - Original Message - > From: "Herb Schoenbohm" > To: > Sent: Friday, August 03, 2012 11:29 AM > Subject: Re: Topband: Antennas > > >> Price, The Military and U.S. Embassies use T2FD type of antennas all >> over their deployment perhaps due to the fact that they do work as long >> as you have plenty of horsepower to feed them with. I think the >> requirement of frequency agility for their requirement outweighs the >> inherent inefficiency. If you don't mind putting a "radiating dummy >> load" in the air then perhaps it is not such a bad idea. The design is >> still part of the military nomenclature with an ANN number and their is >> one on the VI national Guard building a few blocks from my office. It >> is hooked to a 10KW Harris 2-30 Mhz box to connect to FEMA Region 2 on a >> multitude of frequencies driving by the propagation at the moment. The >> T2FD mil spec version is supposed to be rugged enough to work through >> and survive a Cat 4 hurricane. None of my antennas nor towers could make >> that claim. >> >> >> Herb Schoenbohm, KV4FZ >> >> >> >> On 8/3/2012 10:21 AM, HAROLD SMITH JR wrote: >>> Hi Tom, >>> >>> I am suprised that no one has brought up the "T2FD" antenna and >>> of course the B&W "All-Band" antenna. >>> >>> It was in one of the magazines back in the (50s?). >>> >>> 73 >>> Price W0RI >>> ___ >>> UR RST IS ... ... ..9 QSB QSB - hw? BK >> >> ___ >> 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: 2437/5174 - Release Date: 08/03/12 >> > > ___ > 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: 2437/5174 - Release Date: 08/03/12 > ___ UR RST IS ... ... ..9 QSB QSB - hw? BK
Re: Topband: opinion
The problem was that the Ptolemyic concept of a Geo- Centric universe worked for some basic navigational functions, was universally excepted and became part of religious doctrine. Anyone who promoted "truth" of a HelioCentric Universe whether it was Galileo, Copernicus and even later Kepler were condemmed by the chruch. It was the decision of theologians or the state or the church state that called the shots on science. What this did was suppressed advances for a while. Even today we have the impact in our economic survival due to the doxology of AlGore on "climate change" or man-made climate change. Dr. Edward Gray from Bolder was essential drummed out of the very accurate Univ. of Colorado hurricane prediction service for even questioning the new theology of a political control over climate and people as having any significant merit, except for the empowerment of politicians who are engaged in dogma. Why is it always the contrarian views always get in the way of new ideas and punish those who express them. Herb Schoenbohm, KV4FZ On 8/3/2012 3:26 PM, Bruce wrote: > It's a balance. Even a correct new idea sometimes takes it "in the neck" so > to speak. Think of all the crap the first guy took from those that said the > sun was circling the earth. After all you could see it for half of the circle. > > We have to believe what we know is correct, but have an open mind to new > ideas. > > 73 > Bruce > ___ > UR RST IS ... ... ..9 QSB QSB - hw? BK ___ 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
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: opinion
Bruce wrote: > It's a balance. Even a correct new idea sometimes takes it "in the neck" > so to speak. Think of all the crap the first guy took from those that > said the sun was circling the earth. After all you could see it for half > of the circle. That "guy" was Galileo to whom the "Galileo fallacy" refers: Carl Sagan probably put it best when he said: "They laughed at Galileo, they laughed at Newton, but they also laughed at Bozo the clown". Rick ___ UR RST IS ... ... ..9 QSB QSB - hw? BK
Re: Topband: THE ITINERANT 160 METER ANTENNA PROJECT
> > 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. 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. 73 Tom ___ UR RST IS ... ... ..9 QSB QSB - hw? BK
Re: Topband: Antennas
T2FD I though came out around in the Navy since 1940. It is -5 db down from a dipole. Shortened versions past and present are still -5db down from what I have been told. They are very good antennas for emergency stations. 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
> 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)" 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" To: >> 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: Antennas
The T2FD was described in QST for June 1949 and CQ for November 1951 and February 1953, all by USN Capt G.L. Countryman, W3HH. Included are results reported by the USN, who did the design, in comparison to existing antennas as well as detailed construction details. Wire spacing and tilt angle are critical. Ive had one up for several years primarily as a SWL antenna for a couple of boatanchor receivers using a 10W resistor and have also made numerous 10-40W contacts with it without difficulty 80-17M. Ive no comparison wire antennas at similar heights so no performance claims are being made other than that I can work DX and domestic stations with it. The so called T2FD's sold these days by the usual ham dealer suspects is nowhere near the original design so its no stretch as to why its not a great performer. Others just give it a thumbs down without ever trying it and just waste a lot of others time with their views. Carl KM1H - Original Message - From: "Herb Schoenbohm" To: Sent: Friday, August 03, 2012 11:29 AM Subject: Re: Topband: Antennas > Price, The Military and U.S. Embassies use T2FD type of antennas all > over their deployment perhaps due to the fact that they do work as long > as you have plenty of horsepower to feed them with. I think the > requirement of frequency agility for their requirement outweighs the > inherent inefficiency. If you don't mind putting a "radiating dummy > load" in the air then perhaps it is not such a bad idea. The design is > still part of the military nomenclature with an ANN number and their is > one on the VI national Guard building a few blocks from my office. It > is hooked to a 10KW Harris 2-30 Mhz box to connect to FEMA Region 2 on a > multitude of frequencies driving by the propagation at the moment. The > T2FD mil spec version is supposed to be rugged enough to work through > and survive a Cat 4 hurricane. None of my antennas nor towers could make > that claim. > > > Herb Schoenbohm, KV4FZ > > > > On 8/3/2012 10:21 AM, HAROLD SMITH JR wrote: >> Hi Tom, >> >> I am suprised that no one has brought up the "T2FD" antenna and >> of course the B&W "All-Band" antenna. >> >> It was in one of the magazines back in the (50s?). >> >> 73 >> Price W0RI >> ___ >> UR RST IS ... ... ..9 QSB QSB - hw? BK > > ___ > 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: 2437/5174 - Release Date: 08/03/12 > ___ UR RST IS ... ... ..9 QSB QSB - hw? BK
Topband: opinion
It's a balance. Even a correct new idea sometimes takes it "in the neck" so to speak. Think of all the crap the first guy took from those that said the sun was circling the earth. After all you could see it for half of the circle. We have to believe what we know is correct, but have an open mind to new ideas. 73 Bruce ___ UR RST IS ... ... ..9 QSB QSB - hw? BK
Re: Topband: Antennas
Price, The Military and U.S. Embassies use T2FD type of antennas all over their deployment perhaps due to the fact that they do work as long as you have plenty of horsepower to feed them with. I think the requirement of frequency agility for their requirement outweighs the inherent inefficiency. If you don't mind putting a "radiating dummy load" in the air then perhaps it is not such a bad idea. The design is still part of the military nomenclature with an ANN number and their is one on the VI national Guard building a few blocks from my office. It is hooked to a 10KW Harris 2-30 Mhz box to connect to FEMA Region 2 on a multitude of frequencies driving by the propagation at the moment. The T2FD mil spec version is supposed to be rugged enough to work through and survive a Cat 4 hurricane. None of my antennas nor towers could make that claim. Herb Schoenbohm, KV4FZ On 8/3/2012 10:21 AM, HAROLD SMITH JR wrote: > Hi Tom, > > I am suprised that no one has brought up the "T2FD" antenna and > of course the B&W "All-Band" antenna. > > It was in one of the magazines back in the (50s?). > > 73 > Price W0RI > ___ > UR RST IS ... ... ..9 QSB QSB - hw? BK ___ 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)" 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" > To: > 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
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
Topband: Antennas
Hi Tom, I am suprised that no one has brought up the "T2FD" antenna and of course the B&W "All-Band" antenna. It was in one of the magazines back in the (50s?). 73 Price W0RI ___ 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
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" To: 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" >> To: >> 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
Topband: "return" current - what is it?
Hi it was recently stated that the antenna and ground return current at the feed point terminals (where let's assume the TX is located) must always be equal. And this certainly makes sense to me if we treat the antenna/ground system as a circuit (as it often is shown). So I modeled a half wave dipole in free space and sure enough the wire segments on each side of the feed point carried equal current. I then placed a resistive load at the center of one half-element (to simulate? a lossy "return") and now see that those segments no longer carry equal currents, with less current on the side with the load. Can someone please explain this? The Feb 1983 QST article by Doty has 2 tables where they list RF "antenna" and "return" current measurements as they added radials to an elevated counterpoise and ground screen. With 6 radials they measured 350 mA of "antenna" current and 220 mA of "return" current. With 20 radials they measured 495/445 and with 48 radials 495/495. What were they measuring? Thanks Bob ___ UR RST IS ... ... ..9 QSB QSB - hw? BK
