Re: Topband: substandard quality F double females
Has anyone tried RG-8X PL-259 crimp connectors on RG-6? Carl KM1H - Original Message - From: Pete Smith N4ZR n...@contesting.com To: topband@contesting.com Sent: Saturday, December 15, 2012 3:04 PM Subject: Re: Topband: substandard quality F double females Amphenol F connectors? Whoah! 73, Pete N4ZR Check out the Reverse Beacon Network at http://reversebeacon.net, blog at reversebeacon.blogspot.com. For spots, please go to your favorite ARC V6 or VE7CC DX cluster node. On 12/15/2012 12:35 PM, Jim Brown wrote: On 12/15/2012 6:52 AM, Charles Bibb - K5ZK wrote: Which brands/types are the good ones? Amphenol, Amphenol, and Amphenol. Also, the old MIL-spec stuff that can be found at most hamfests when OTs clean out their basements. The shiny new connectors and adapters sold by vendors at hamfests are junk -- the center conductors are flimsy, often no more than springs. I've had cheap connectors fall apart mechanically, the dielectric of connectors intended for soldering will sometimes melt, and so on. These junk connectors go intermittent, or overheat with power. 73, Jim K9YC ___ Topband reflector - topband@contesting.com ___ Topband reflector - topband@contesting.com - No virus found in this message. Checked by AVG - www.avg.com Version: 10.0.1430 / Virus Database: 2634/5461 - Release Date: 12/15/12 ___ Topband reflector - topband@contesting.com
Re: Topband: GAP Vertical Question
My own experience with 1/2 wave verticals is that they certainly do require a good ground. Maybe a rod in a saltwater marsh is sufficient but not in many other cases. Examples: A Shakespere CB whip in my 66 Corvette which was advervtised for fiberglass cars. It couldnt be heard a mile away with 4W. I added radials from the base on the rear deck to the frame on all 4 corners and then it worked much better. This was back in the late 70's for several years. A 80/40M 6 wire cage vertical, a full quarter wave on 80 and hanging from a tall pine tree branch at a prior QTH. With 60 65-70' radials it was competitive on 80 and on 40. With the radials removed it was a dud on 40. With another phased 1/4 wave on 80 it delivered the gain and F/B expected and 40 was improved with a pair of figure 8's but still not up to expectations. A 4el 40M KLM at 120' fixed that. Carl KM1H - Original Message - From: Richard (Rick) Karlquist rich...@karlquist.com To: Donald Chester k4...@hotmail.com Cc: topband@contesting.com Sent: Saturday, December 15, 2012 3:58 PM Subject: Re: Topband: GAP Vertical Question On 12/15/2012 12:03 PM, Donald Chester wrote: From: charlie-cunning...@nc.rr.com Could you support a vertical 1/2 wave for 160 with aballoon? You could end -feed it at the base through a 1/4 wave of 450 ohm But feeding a half wave vertical with the base near the ground still results in substantial ground losses without a radial system. Don k4kyv And this statement is based on what? Publications, measurements, modeling? I have built a number of 1/2 wave verticals without radials and compared them to 1/4 wave verticals with radials. They are indistinguishable in performance and certainly do not exhibit substantial ground losses AFAIK. The PAR electronics 1/2 wave end fed antenna seems to have a good reputation, unlike some GAP verticals. However, I don't recommend feeding it through 1/4 wave of 450 ohm open wire line. I just use an LC matching network. Rick N6RK ___ Topband reflector - topband@contesting.com - No virus found in this message. Checked by AVG - www.avg.com Version: 10.0.1430 / Virus Database: 2634/5461 - Release Date: 12/15/12 ___ Topband reflector - topband@contesting.com
Re: Topband: raised radials
You ever wonder why a few on here are so much louder than their competition with similar installations when 1-2 keep trying to make us believe it has nothing to do with the radials beyond a small number? IF he is correct then why the big difference? Anybody care to offer a guess? Or the fellow on a city lot that knows he is 10dB below the guy a mile away out in the country with a big vertical or T with lots of long radials plus a base meshafter several years of comparisons. You dont need fancy test equipment to see that. Ever wonder why photos of elevated radial BC antennas show a base mesh and a small number of radials? And then performance tests require a reduction in power to conform to the canned 120 radials in the ground benchmark signal strength. Or due to the stations original certification with a full set of base radials that rotted away and the elevated are the replacements. Or the person on here who went from an extensive radial system to a full screen claimed a 5dB improvement but now denys the possibility. Its in the TB archives from 1998. A few seem to be in a continuous rut with impedance the only factor they seem to mention. There is a lot more than just the immediate soil under the radials that is involved when it comes to field strength many wavelengths or continents away which also affects the energy in a particular elevation angle. Carl KM1H - Original Message - From: Charlie Cunningham charlie- Hee! :- ) -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Tom W8JI Sent: Saturday, December 15, 2012 7:12 PM To: DAVID CUTHBERT; Carl Cc: David Michael Gaytko // WD4KPD; topband@contesting.com Subject: Re: Topband: raised radials That is quite an improvement. I had to have dropped the base impedance from 400 ohms to 40 ohms for it to do that. Things are often magic when we rely on feelings or emotions to measure decibels. ___ Topband reflector - topband@contesting.com - No virus found in this message. Checked by AVG - www.avg.com Version: 10.0.1430 / Virus Database: 2634/5462 - Release Date: 12/15/12 ___ Topband reflector - topband@contesting.com
Re: Topband: GAP Vertical Question
How long did the KLM last before the light boom folded, or the element to boom brackets failed or the linear loaded insulator let go? One good wind storm? Doug Think of all the ways you can hurt yourself laughing. -Original Message- A 4el 40M KLM at 120' fixed that. Carl KM1H ___ Topband reflector - topband@contesting.com
Re: Topband: raised radials
Or the person on here who went from an extensive radial system to a full screen claimed a 5dB improvement but now denys the possibility. Its in the TB archives from 1998. Carl, Please try to stop that silly disappointing long-time practice of re-writing what other people say just to start a fight. I NEVER said I didn't measure a 5 dB change, or that some system changes can't produce a 5 dB (or even a 30 dB) change when someone does something terribly wrong in a system. What I am saying is: 1.) Your claim you felt you had a ~10 dB change, based on your feelings of how much a signal must change busting a pileup, when you added some screen to a system is pretty silly. It is a test at least days apart on sky wave with no data reference at all. It is typical junk science of the worse kind. If your original ground system did not have severe issues, the imagined 10 dB would be impossible. 2.) Broadcast stations use a screen as a connection point and mechanical convenience, NOT to improve signal or effiency. The screen allows people to walk near the tower base without falling over wires, and it allows connecting boxes, fences, posts, and other things into the radials no matter where they are located near the base. They also usually use stone at the base, and weedkiller...so we can't assume everything they do is for signal reasons. If you take some time to read FCC guidelines, the screen is actually optional. If you read Lewis, Brown, and Epstein, instead of misreading Topband archives, you will see they ALSO said the screen does not when a adequate number and length of radials is present. Please stop the silly childish misrepresentations. 73 Tom ___ Topband reflector - topband@contesting.com
Re: Topband: GAP Vertical Question
A Shakespere CB whip in my 66 Corvette which was advervtised for fiberglass cars. It couldnt be heard a mile away with 4W. I added radials from the base on the rear deck to the frame on all 4 corners and then it worked much better. This was back in the late 70's for several years. CB antenna manufacturers live in a fantasy land, and almost always grossly misrepresent what the sell. A half wave CB whip is about 18 feet long. It is impossible to use a half wave whip on 11 meter mobile on a normal highway or road. You likely had an antenna with 1/2 wave of wire spooled up on a short fiberglass rod, which would never behave like a half-wave. ___ Topband reflector - topband@contesting.com
Topband: Fw: raised radials
Subject: Re: Topband: raised radials All the years I have been on top band, I can't recall ever hearing or working him - DXing on Contesting. With all his hardware on 160, surely sometime his presence would be evident other than the reflector... Anyone else? Merry Christmas to all. 73 Bob W3GH Subject: Re: Topband: raised radials AMEN Tom, He Just is like the Energizer Bunny. He keeps going on and on and on. 73 and Happy Holidays Price W0RI Or the person on here who went from an extensive radial system to a full screen claimed a 5dB improvement but now denys the possibility. Its in the TB archives from 1998. Carl, Please try to stop that silly disappointing long-time practice of re-writing what other people say just to start a fight. I NEVER said I didn't measure a 5 dB change, or that some system changes can't produce a 5 dB (or even a 30 dB) change when someone does something terribly wrong in a system. What I am saying is: 1.) Your claim you felt you had a ~10 dB change, based on your feelings of how much a signal must change busting a pileup, when you added some screen to a system is pretty silly. It is a test at least days apart on sky wave with no data reference at all. It is typical junk science of the worse kind. If your original ground system did not have severe issues, the imagined 10 dB would be impossible. 2.) Broadcast stations use a screen as a connection point and mechanical convenience, NOT to improve signal or effiency. The screen allows people to walk near the tower base without falling over wires, and it allows connecting boxes, fences, posts, and other things into the radials no matter where they are located near the base. They also usually use stone at the base, and weedkiller...so we can't assume everything they do is for signal reasons. If you take some time to read FCC guidelines, the screen is actually optional. If you read Lewis, Brown, and Epstein, instead of misreading Topband archives, you will see they ALSO said the screen does not when a adequate number and length of radials is present. Please stop the silly childish misrepresentations. 73 Tom ___ Topband reflector - topband@contesting.com ___ Topband reflector - topband@contesting.com - No virus found in this message. Checked by AVG - www.avg.com Version: 2012.0.2221 / Virus Database: 2637/5464 - Release Date: 12/16/12 ___ Topband reflector - topband@contesting.com
Re: Topband: raised radials
- Original Message - From: Tom W8JI w...@w8ji.com To: Carl k...@jeremy.mv.com Cc: topband@contesting.com Sent: Sunday, December 16, 2012 11:26 AM Subject: Re: Topband: raised radials Or the person on here who went from an extensive radial system to a full screen claimed a 5dB improvement but now denys the possibility. Its in the TB archives from 1998. Carl, Please try to stop that silly disappointing long-time practice of re-writing what other people say just to start a fight. I NEVER said I didn't measure a 5 dB change, or that some system changes can't produce a 5 dB (or even a 30 dB) change when someone does something terribly wrong in a system. ** Some time spent in the archives could be an eye opener to many on here. Im far from looking for a fight as you claim, just get some things clarified. What I am saying is: 1.) Your claim you felt you had a ~10 dB change, based on your feelings of how much a signal must change busting a pileup, when you added some screen to a system is pretty silly. It is a test at least days apart on sky wave with no data reference at all. It is typical junk science of ** Thats about what Id expect from you, demeaning comments when you dont have a clue what I did. The radials only were for over a year of daily operating so I had a pretty decent feel for the bands variances. This was a decade before Topband came along. The screen went down one day and by sunset I was active again, didnt miss a beat. The group of friends I worked with on a private 222MHz repeater all commented on the improvement since I was regularly beating them in pileups and they had good vertical installations. the worse kind. If your original ground system did not have severe issues, the imagined 10 dB would be impossible. ** You are very wrong since you remain hung up on only part of the picture. 2.) Broadcast stations use a screen as a connection point and mechanical convenience, NOT to improve signal or effiency. ** Wrong again since you conveniently leave out the rest of the reason. The screen allows people to walk near the tower base without falling over wires, and it allows connecting boxes, fences, posts, and other things into the radials no matter where they are located near the base. They also usually use stone at the base, and weedkiller...so we can't assume everything they do is for signal reasons. ** Nope and that is a completely different install than what I am discussing where the close in base screen plus elevated radials is used as a necessity for mainly financial reasons. If you take some time to read FCC guidelines, the screen is actually optional. ** Ive read it and you are changing the subject again If you read Lewis, Brown, and Epstein, instead of misreading Topband archives, ** My reading suggests quite different. you will see they ALSO said the screen does not when a adequate number and length of radials is present. Please stop the silly childish misrepresentations. 73 Tom ** Stop the demeaning and subject switching/slanting whenever you get into a jam Tom. This is not Eham or QTH, there are many educated readers on here that can see right thru it Carl KM1H. ___ Topband reflector - topband@contesting.com
Re: Topband: GAP Vertical Question
On 12/16/2012 8:31 AM, Tom W8JI wrote: You likely had an antenna with 1/2 wave of wire spooled up on a short fiberglass rod, which would never behave like a half-wave. You are exactly right. Unfortunately, this myth dies hard. A few years ago a ham magazine had a article about a 160 meter vertical that utilized a half wave of wire helically wound on plastic tubing a few dozen feet high. Rick N6RK ___ Topband reflector - topband@contesting.com
Topband: Strange Condx
Friday late afternoon around 4 pm (EST), I was listening to 160 and was hearing many signals from Europe and Russia. Some were quite loud. I probably called at least a dozen different stations with no luck. My transmit antenna is an inverted L which is about 85 feet vertical. I even went outside to make sure the horizontal leg was not disturbed due to wind. I operate EME on 144 mhz and have had times where signals would only go one way. Was this the case ? Or could it have been storms which would have produced high levels of noise on their receive end ? After a radio club dinner, I went back to 160 and was able to work two stations in Europe with single calls from me. I'm going to try the SP contest next weekend for some fun Isn't this the greatest hobby ever ? Herb K2LNS ___ Topband reflector - topband@contesting.com
Re: Topband: Fw: raised radials
The 10 dB, or was it 20 dB, claim could be a case of belief preservation as described in section 3.5 of the paper *Teaching Critical Thinking: Lessons for Cognitive Science*, by Tim van Gelder http://frank.itlab.us/forgetting/teaching_critical_thinking.pdf Dave WX7G ___ Topband reflector - topband@contesting.com
Re: Topband: Optimal radial wire type and gauge?
Tom, I think you are extrapolating one case with a particular radial length to all vertical antenna ground systems. The N6LF radial papers detail his NEC-4 simulations and measurements of vertical antennas and radial systems. If I read his papers correctly base impedance does track field strength measurements. http://www.antennasbyn6lf.com/ Dave WX7G On Sat, Dec 15, 2012 at 5:10 PM, Tom W8JI w...@w8ji.com wrote: There is no magic about 120 radials, and long before 120 radials are reached the increase in field strength pretty much stops. At my house around 30 radials or so, about 1/4 wave long, go flat on efficiency increase on 160 meters. I could have a million radials and it would be insignificantly different than 30 radials when they are 1/4 wave long here. I found this by measuring field strength, and I also found feed resistance change did NOT necessarily track the field strength changes. Good luck on using base impedance to determine effiency changes! In a 40 meter test, for example, one ground system provided 35-40 ohms of feed resistance and another different system that provided almost 60 ohms of feedpoint resistance had equal field strength. I think N6RK and others have measured the same. 73 Tom - Original Message - From: DAVID CUTHBERT telegraph...@gmail.com To: Rick Kiessig kies...@gmail.com Cc: topband@contesting.com Sent: Saturday, December 15, 2012 10:49 AM Subject: Re: Topband: Optimal radial wire type and gauge? Read the N6LF radial papers and you will see that 1/8 wavelength radials are about as good as one can do. I use #14 stranded copper THHN wire because it is easy to work with. But how good can we get? For a 30' base loaded vertical I have 90 radials having an average length of 18 ft. The ground loss is 5 ohms, which is less than the loading coil loss. If I were to install 120 quarter wavelength radials I would gain 2 dB. Dave WX7G __**_ Topband reflector - topband@contesting.com ___ Topband reflector - topband@contesting.com
Re: Topband: GAP Vertical Question
Then, why do broadcast stations that use vertical towers at approximately a half wavelength, purchase valuable real estate and spend thousands of dollars for the copper to install from 120 to 240 or more radials, each usually a half wave or more in length? See G. H. Brown: Ground Systems as a Factor in Antenna Efficiency, IRE Proceedings, June 1937 p. 753. Brown demonstrated that the distribution of earth currents and ground losses is such that the region of maximum current and loss occurs at a distance of about 0.35 wavelengths from the base of a ground mounted half wave vertical antenna, which was verified experimentally. There is zero loss at the base of the antenna itself, since there is no base current because the antenna a fed at a current node. An rf ammeter inserted in the ground lead, as well as one inserted in in the antenna lead attached to the insulated base of the radiator will read zero. The ground losses occur farther out from the base of the antenna. Low effective earth resistance provided by a good ground system is ABSOLUTELY NECESSARY for vertical antennas of ANY height if one expects good radiation efficiency. The claim that no ground system is needed for a half wave vertical is nothing more than a long-standing popular misconception. This topic prompted me to dig out and review an anecdote I recall reading in my decades-old copy of CQ magazine's Vertical Antenna Handbook, by USNR Capt. Paul H. Lee, K6TS (1974). He reported receiving mail from a ham who had made the discovery that he could tune and operate a half wave vertical without a ground system, feeding it by a parallel tuned tank circuit whose lower end is grounded. Since an rf ammeter in the ground lead showed no current, he could dispense with the ground system and its loss. He suggested to the Capt. that he should discover the new world of half verticals with no ground system. Quoting from the text (p. 84): The correspondent's claim... is true ONLY IF HE IS CONTENT TO THROW AWAY FROM 40 TO 80 PER CENT OF HIS RADIATED POWER IN THE FORM OF EARTH LOSSES. (the correspondent) stated, 'The ZL's call ME, when I use my half wave vertical!' This is not surprising, in view of the fact that the half wave's vertical pattern has a lower main lobe angle than a quarter wave would have... However, he would hit the ZL's even harder if he would put in a ground system. Of course, the half wave vertical is not dependent on a ground plane, however lossy or efficient, for the condition of RESONANCE, since it is resonant in itself because of its half wave length. However, IT IS DEPENDENT ON A GROUND PLANE FOR ITS EFFICIENCY OF RADIATION, as is any vertical antenna...' Don k4kyv Given that a half wave vertical has a base impedance of over 1000 ohms and a single ground rod in dirt is 100 ohms at most not a single radial is needed to obtain close to 100% radiation efficiency. Dave WX7G And this statement is based on what? Publications, measurements, modeling? I have built a number of 1/2 wave verticals without radials and compared them to 1/4 wave verticals with radials. They are indistinguishable in performance and certainly do not exhibit substantial ground losses AFAIK... Rick N6RK I can think of NO earthly reason,that makes ANY electromagnetic sense to me, as antenna engineer fo placing a radial system under the end of a vertical 1/2 wave antenna - earth-worms not withstanding! It's CURRENT that warms the earthworms! NOT electric field intensity! ...the ground system does NOT act as a shield from the lossy earth nor protect the earth-worms! There is absolutely NO reason to require a radial system under a 1/2 wave vertical antenna. Such an antenna will operate just fine on its own in free-space. Consider this - to deliver 1000 watts to a 1/4 wave vertical with a REALLY GOOD ground system and a driving point impedance of say 40 ohms would require 5 amps of RF current delivered to the antenna system and ground. Todeliver that same 1000 watts to an end-fed vertical of 2000-4000 ohms real would require an antenna current, at the fed endof 0.5 -0.7 amps! It's the CURRENT that produces the losses in the lossy earth and warms the earth worms. At worst, for the 1/2 wave end fed vertical - a simple ground rodshould be just fine, and the earth worms should be quite comfortable, and the antenna will work VERY well!! Of course it will be 250-260 feet tall! Charlie,K4OTV ___ Topband reflector - topband@contesting.com
Re: Topband: GAP Vertical Question
Hi Don, Then, why do broadcast stations that use vertical towers at approximately a half wavelength, purchase valuable real estate and spend thousands of dollars for the copper to install from 120 to 240 or more radials, each usually a half wave or more in length? They almost always do not. First, they would be fools or have idiots for engineers to have more than 120 radials. The only real reason they use 90 radials or so is it sometimes gets them out of expensive proof-of-performance measurements. The exact FCC text is down the page here: http://www.w8ji.com/counterpoise_systems.htm Second, nearly all stations except the old clear channels on the low end use towers around 1/4 wave, often just around 0.2 WL. See G. H. Brown: Ground Systems as a Factor in Antenna Efficiency, IRE Proceedings, June 1937 p. 753. Brown demonstrated that the distribution of earth currents and ground losses is such that the region of maximum current and loss occurs at a distance of about 0.35 wavelengths from the base of a ground mounted half wave vertical antenna, which was verified experimentally. But the field is so weak at that point that there really isn't much to be gained when the radiator is 1/2 wave tall. Plus broadcast stations have a huge investment, and overkill is not an issue for them. That's why the transmitters are so conservative. There is zero loss at the base of the antenna itself, since there is no base current because the antenna a fed at a current node. An rf ammeter inserted in the ground lead, as well as one inserted in in the antenna lead attached to the insulated base of the radiator will read zero. That is absolutely wrong. A typical half-wave BC tower is in the several hundred ohm range because of tower thickness. They are almost never over 1000 ohms. Halfwave BC towers at exact resonance are typically about 1 ampere per kilowatt. There isn't an end-fed half wave in the world with infinite impedance and zero current, even the very thinnest lossless wire would not be zero. The ground losses occur farther out from the base of the antenna. Low effective earth resistance provided by a good ground system is ABSOLUTELY NECESSARY for vertical antennas of ANY height if one expects good radiation efficiency. The claim that no ground system is needed for a half wave vertical is nothing more than a long-standing popular misconception. Actually we do need a ground system, that much is correct, but requirements are much relaxed from very short antennas. With a half wave end fed wire element it is pretty tough to lose more than one or two dB in ground loss, but it certainly needs something there to allow it to be fed. It cannot be fed without some counterpoise. Thick towers are another matter. The surge impedance of the tower is so low that end impedance never gets all that high. This is why thick antennas are wide bandwidth, and why extreme power SWBC stations use thick cage elements. They do that to keep the impedance extremes, even at the open element end, down. This topic prompted me to dig out and review an anecdote I recall reading in my decades-old copy of CQ magazine's Vertical Antenna Handbook, by USNR Capt. Paul H. Lee, K6TS (1974). He reported receiving mail from a ham who had made the discovery that he could tune and operate a half wave vertical without a ground system, feeding it by a parallel tuned tank circuit whose lower end is grounded. Since an rf ammeter in the ground lead showed no current, he could dispense with the ground system and its loss. He suggested to the Capt. that he should discover the new world of half verticals with no ground system. Current is not zero. It cannot be zero at the feedpoint of any end-fed antenna. That is an absolute practical and theoretical impossibility. It is a myth or a pretty gross misconception. While Captain Lee had a lot of good stuff, he was also over the top with some things. It is quite easy, with a thin vertical half-wave element, to get into the 80% efficiency range with a very minimal ground screen. People think of losses as current flow problems, but a significant portion of losses in a half wave ground independent vertical are electric field induced losses at the antenna base. The same would be true for a thin element and no radials, and just a ground rod or several ground rods. Thinner half wave verticals are pretty efficient with a minimal ground. When they get extremely thick the base current increases, and conduction losses can be a significant factor. 73 Tom ___ Topband reflector - topband@contesting.com
Re: Topband: Optimal radial wire type and gauge?
Tom, I think you are extrapolating one case with a particular radial length to all vertical antenna ground systems. The N6LF radial papers detail his NEC-4 simulations and measurements of vertical antennas and radial systems. If I read his papers correctly base impedance does track field strength measurements. http://www.antennasbyn6lf.com/ Hi Dave, Historically there probably have been more cases where base impedance does not directly allow loss calculations than where it does correlate. The case where feed resistance and efficiency closely agrees at all numbers of radials would be very special. One case would be where the radials are exactly 1/4 wave long electrically, so the antenna base is at a radial current maximum, and the antenna is 1/4 wave tall. In that case all of the CONDUCTED ground losses could be directly applicable as a feedpoint resistance change. Field losses from fields impinging on earth would not factor in well, but they could be small. The rule I learned to always apply to theory is where there is an exception, the theory is no longer correct or valid unless the theory includes **all** exceptions as part of the theory. If a ground system has standing waves, which even buried radials do to a significant extent in sparse radial systems, the impedance at the base is not representative of the real loss resistance. I have found that here in several cases, not just one, and others have also independently reported it without intentionally looking for it. If it is UNreliable in some case or cases, it cannot be an accurate theory for general application. To use the theory, you would have to qualify the exceptions so people could avoid them. To not use the theory do not require any qualification. An accurate field strength measurements is always right. A base resistance reading might be right or wrong. it might be useful or not useful. 73 Tom ___ Topband reflector - topband@contesting.com
Re: Topband: GAP Vertical Question
Charlie, your starting to sound like the other guy; trying to interpet my posts and spin to your benefit and getting demeaning in the process. Give me a bit more credit than that...OK... I know a bit about antennas. To be a bit more clear the tuner was always connected to a ground.. First to just an 8' rod and then the #6 copper ring around it with the 60 radials. Even the coax was ferrite decoupled as I was far ahead of the pack with their use having worked on the Tempest program as already mentioned. Carl KM1H - Original Message - From: Charlie Cunningham charlie-cunning...@nc.rr.com To: 'Carl' k...@jeremy.mv.com; 'Richard (Rick) Karlquist' rich...@karlquist.com; 'Donald Chester' k4...@hotmail.com; Tom W8JI w...@w8ji.com Cc: topband@contesting.com Sent: Sunday, December 16, 2012 12:06 PM Subject: RE: Topband: GAP Vertical Question Well, Carl Your experience with your 6-wire cage vertical - 1/4 wave on 80 - AND 1/2 wave on 40 was not very enlightening or satisfying and led to some serious misunderstanding!! When you removed the radials - OF COURSE it was a DUD on 40 -if you just left the coax feed in place!! You were trying to end-feed a 1/2 wave resonant antenna on 40m from coax - you must have a heck of a tuner, but the VSWR and mismatch loss were so high that you weren't delivering much of anything to the antenna!! Most of your power was being dissipated in heating the coax operating at very high VSWR!! You could have turned it into an excellent 40m antenna if you had end fed it through a 40m 1/4 wave open wire ladder line or fed it from the top end of a 40 m parallel tuned circuit (cold-end grounded, of course) tapped for a match to your 50 ohm coaxial feed line. If it still worked on 80 without the radials, there must have been a fortuitous length of coaxial shield to supply the missing lower 1/2 of the antenna! But you solved the problem without ANY understanding and put up 4 40m elements at 120 feet! The problem was NOT a GROUND PROBLEM - but was rather one of operator head-spacing! There must have been a hellacious VSWR on that COAX trying to feed that 1/2 wave vertical cage at the end with no radials. Your understanding of antennas, resonance, matching and grounding seems to leave a LOT to be desired! Perhaps some reading and study would help! Regards, Charlie, K4OTV P.S. A 1/2 wave vertical does NOT need a salt water marsh under it to work VERY well! In fact a vertical 1/2 wave in free space also works very well!! -Original Message- From: Charlie Cunningham [mailto:charlie-cunning...@nc.rr.com] Sent: Sunday, December 16, 2012 9:16 AM To: 'Carl'; 'Richard (Rick) Karlquist'; 'Donald Chester' Cc: 'topband@contesting.com' Subject: RE: Topband: GAP Vertical Question Good morning, Carl Well, a 1/4 wave vertical absolutely requires a ground plane!! A vertical 1/2 wave - not really! It seems that, in your observations, you are mixing the two? Any 1/4 wave vertical absolutely does need an image plane to work against! Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Carl Sent: Saturday, December 15, 2012 7:46 PM To: Richard (Rick) Karlquist; Donald Chester Cc: topband@contesting.com Subject: Re: Topband: GAP Vertical Question My own experience with 1/2 wave verticals is that they certainly do require a good ground. Maybe a rod in a saltwater marsh is sufficient but not in many other cases. Examples: A Shakespere CB whip in my 66 Corvette which was advervtised for fiberglass cars. It couldnt be heard a mile away with 4W. I added radials from the base on the rear deck to the frame on all 4 corners and then it worked much better. This was back in the late 70's for several years. A 80/40M 6 wire cage vertical, a full quarter wave on 80 and hanging from a tall pine tree branch at a prior QTH. With 60 65-70' radials it was competitive on 80 and on 40. With the radials removed it was a dud on 40. With another phased 1/4 wave on 80 it delivered the gain and F/B expected and 40 was improved with a pair of figure 8's but still not up to expectations. A 4el 40M KLM at 120' fixed that. Carl KM1H - Original Message - From: Richard (Rick) Karlquist rich...@karlquist.com To: Donald Chester k4...@hotmail.com Cc: topband@contesting.com Sent: Saturday, December 15, 2012 3:58 PM Subject: Re: Topband: GAP Vertical Question On 12/15/2012 12:03 PM, Donald Chester wrote: From: charlie-cunning...@nc.rr.com Could you support a vertical 1/2 wave for 160 with aballoon? You could end -feed it at the base through a 1/4 wave of 450 ohm But feeding a half wave vertical with the base near the ground still results in substantial ground losses without a radial system. Don k4kyv And this statement is based on what? Publications, measurements, modeling? I have built a number of 1/2 wave verticals without radials and compared them to 1/4 wave verticals with
Re: Topband: raised radials
Charlie, you are so far off the wall Im not even going to bother with a long detailed answer since it likely wont go thru.You dont have a clue what Im trying to get across so why bother. There was absolutely nothing wrong with my 40M configurations, one version wasnt up to expectations and the other was much better. By how much I dont know since the difference was marked and not worth going further. This 1/2 wave working better with radials is nothing new and has been reported by others and is used in some commercial antenna mobile installations on VHF and up. What I called a dud by my standards is likely what you call a great performer, it didnt crack pileups on the first few calls. With radials it was better but not great. Maybe the angle was too low, anyway I dont like waiting and search for the reasons why. Running super QRO is not in my playbook. The HB tuning network worked perfect either way and the only reason I disconnected the radial ring was out of curiosity since fellow ham engineers at work asked about it. Engineering requires curiosity as well as an understanding. Im not one to blindly follow the Pied Piper. It is called testing and verification, are you familiar with those concepts? The 4 el 40M yagi was installed since I wanted to work ALL countries/zones on the band as well as generate big contest scores. I wasnt satisfied with an underperformer altho at times the radial version vertical halfwave was pretty close (easily audible so maybe 3-4dB?) to the 4el on some rare occassions. The KLM was an available product and I could afford it and the tower dedicated to it, Im being condemned for that now? Your comment of antennas on tall buildings further shows your inability to seperate apples and oranges and stick to one subject.. All Ive read in this last rambling and ranting post of yours is from a seriously disturbed old man ( Im a bit older) who might have a stroke if he doesnt calm down and stop going on about something you apparently have trouble reading much less understanding. If you dont understand something ask for a clarification, dont just throw a grenade in the room. I'll go one to one with you on antennas any day of the week but first you need to understand how antennas work beyond your back yard. There was a long discussion on here led by a known BC engineer who took a lot of flack from a few who were being challenged. I enjoyed watching the constant dancing and subject shifting smoke screens by the usual. Well written engineering books give you the basics, I have had all of them for decades and reference them often but a dedicated professor that took the time to explain troublesome parts to any student was worth his weight in gold. And you dont need to keep adding the groupie addresses since it does go thru the reflector to everyone. Carl KM1H Well, Carl, before you start beating up on Tom, let me assure you that there ARE some people on this reflector. And I AM one of them, who are certainly educated and informed enough, and do antenna work professionally, as I do, to see the serious and gross errors and complete lack of knowledge and understanding that regularly are presented in your presentations on antennas and grounds here on this reflector. I expect that most of them are so appalled and taken aback, that they often just dismiss your rants out of hand, as I have, and just don't dignify them with a comment! But here lately some of your rants are so seriously in error, and in such complete disagreement with the laws of physics, electromagnetics and engineering, that I feel compelled to speak out! Let me start by telling you that I AM an electrical engineer, and I have been practicing for 45 years -and among other things, I AM an antenna engineer, and I know enough about antennas and electromagnetics to know complete BULL and SERIOUS ERRORS when I see them! And you surely have presented us with some!! Let me tell you, as an antenna engineer, that antennas and electromagnetics are based on DESIGN, MODELING, CONSTRUCTION, MEASUREMENT and TESTING - with a firm foundation in the underlying science and engineering!! You seem to be sadly lacking in this area!! One of my concerns is that some of the less-informed who read your bull in this reflector might take it seriously!! As an engineer, I can just dismiss it as BULL, based on apocrypha, hearsay and half-baked opinions -NOT on any underlying science or engineering - but others might not, - and they might expend a lot of sweat and tears and MONEY (4 40m elements a 120' -to solve a gross and serious electromagnetics error???) by following some of your SERIIOUSL FLAWED RANTS! You need to get away from your computer and keyboard and go dig into some serious antenna and electromagnetics texts!! May I recommend Antennas, by John Kraus, W8JK, of Ohio State University (McGraw- Hill 1950) SK Note: 1.0 A 1/2 wave vertical DOES NOT need an underlying ground
Re: Topband: Strange Condx
Hi, Herb! Well, it's easy to forget that receiving conditions can be quite different at different ends of the path! An hour before your sunset, it had been dark for a while western and central Europe and the noise level on 160 can often pick up as darkness settles in on the eastern end of the daylight path. Also, it's worth keeping in mind that most of Western Europe is at considerably higher latitude than we are and may be more subject to auroral-related disturbance and noise! A good example showed up last night. I was sitting here and watching DX Summit on my computer in between work tasks. I especially like to watch 30m spots. A W7 remarked about a Chinese BA7 station bad ears and the Chinese op, apparently was watching, and posted the W7's call and said Sorry - GP antenna and S6 noise level. So we don't always know what the guy a world away is up against, and it's worth remembering, too, if we post critical remarks on the DX clusters, the other op may be watching also and be offended or suffer some hurt feelings Regards, Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Herb Krumich Sent: Sunday, December 16, 2012 6:47 PM To: topband@contesting.com Subject: Topband: Strange Condx Friday late afternoon around 4 pm (EST), I was listening to 160 and was hearing many signals from Europe and Russia. Some were quite loud. I probably called at least a dozen different stations with no luck. My transmit antenna is an inverted L which is about 85 feet vertical. I even went outside to make sure the horizontal leg was not disturbed due to wind. I operate EME on 144 mhz and have had times where signals would only go one way. Was this the case ? Or could it have been storms which would have produced high levels of noise on their receive end ? After a radio club dinner, I went back to 160 and was able to work two stations in Europe with single calls from me. I'm going to try the SP contest next weekend for some fun Isn't this the greatest hobby ever ? Herb K2LNS ___ Topband reflector - topband@contesting.com ___ Topband reflector - topband@contesting.com
Re: Topband: Strange Condx
Hi, Herb! Yes - and sometimes the daytime noise level will be a bit lower on 160 and then pick up as the grey line and then darkness move over us! And I can sympathize with those Europeans - and being in the city, where my inverted L with the three resonant elevated radials has been somewhat maligned here (it's down now because a bad storm/hurricane tilted the tree that was supporting the far end of the flat top portion and we had to take it down with a crane), I generally found that, if I could hear them, I could work them! My problem was hearing!! BEST thing I EVER did for myself on 160 and 80 was to build a modest size KAZ terminated receiving loop that I ran through an old AMECO preamp into the receive antenna port on the FT-1000MP. Suddenly I could HEAR stations that I just couldn't tell were there or make out when copying on the Inverted L or my quad. Beverages are completely out of the question for me. The loop worked great on 80 also and was a really good receiving antenna for 40 and 30 also. I need to relocate and rearrange my inverted L. Thank heavens it wasn't being operated against a buried radial field!! J I hope you and yours have a wonderful Christmas, Herb!! Best regards, Charlie, K4OTV FRom: Herb Krumich [mailto:wa2...@yahoo.com] Sent: Sunday, December 16, 2012 7:29 PM To: Charlie Cunningham Subject: Re: Topband: Strange Condx Thanks Charlie Yes many years ago I learned that we might have a quiet band, but others might not. Some very good points you made. Always willing to learn from others Merry Christmas Herb From: Charlie Cunningham charlie-cunning...@nc.rr.com To: 'Herb Krumich' wa2...@yahoo.com Cc: topband@contesting.com Sent: Sunday, December 16, 2012 6:23 PM Subject: RE: Topband: Strange Condx Hi, Herb! Well, it's easy to forget that receiving conditions can be quite different at different ends of the path! An hour before your sunset, it had been dark for a while western and central Europe and the noise level on 160 can often pick up as darkness settles in on the eastern end of the daylight path. Also, it's worth keeping in mind that most of Western Europe is at considerably higher latitude than we are and may be more subject to auroral-related disturbance and noise! A good example showed up last night. I was sitting here and watching DX Summit on my computer in between work tasks. I especially like to watch 30m spots. A W7 remarked about a Chinese BA7 station bad ears and the Chinese op, apparently was watching, and posted the W7's call and said Sorry - GP antenna and S6 noise level. So we don't always know what the guy a world away is up against, and it's worth remembering, too, if we post critical remarks on the DX clusters, the other op may be watching also and be offended or suffer some hurt feelings Regards, Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Herb Krumich Sent: Sunday, December 16, 2012 6:47 PM To: topband@contesting.com Subject: Topband: Strange Condx Friday late afternoon around 4 pm (EST), I was listening to 160 and was hearing many signals from Europe and Russia. Some were quite loud. I probably called at least a dozen different stations with no luck. My transmit antenna is an inverted L which is about 85 feet vertical. I even went outside to make sure the horizontal leg was not disturbed due to wind. I operate EME on 144 mhz and have had times where signals would only go one way. Was this the case ? Or could it have been storms which would have produced high levels of noise on their receive end ? After a radio club dinner, I went back to 160 and was able to work two stations in Europe with single calls from me. I'm going to try the SP contest next weekend for some fun Isn't this the greatest hobby ever ? Herb K2LNS ___ Topband reflector - topband@contesting.com ___ Topband reflector - topband@contesting.com
Re: Topband: Optimal radial wire type and gauge?
Well, I suspect that one can't get a complete picture of the correlation between base driving point impedance and radiated field intensity unless we could measure at a multiplicity of elevation angles. Has anyone looked into changes in the elevation pattern as the ground systems are modified? Much easier said than done!! Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of DAVID CUTHBERT Sent: Sunday, December 16, 2012 8:06 PM To: Tom W8JI Cc: topband@contesting.com; Rick Kiessig Subject: Re: Topband: Optimal radial wire type and gauge? Tom, I think you are extrapolating one case with a particular radial length to all vertical antenna ground systems. The N6LF radial papers detail his NEC-4 simulations and measurements of vertical antennas and radial systems. If I read his papers correctly base impedance does track field strength measurements. http://www.antennasbyn6lf.com/ Dave WX7G On Sat, Dec 15, 2012 at 5:10 PM, Tom W8JI w...@w8ji.com wrote: There is no magic about 120 radials, and long before 120 radials are reached the increase in field strength pretty much stops. At my house around 30 radials or so, about 1/4 wave long, go flat on efficiency increase on 160 meters. I could have a million radials and it would be insignificantly different than 30 radials when they are 1/4 wave long here. I found this by measuring field strength, and I also found feed resistance change did NOT necessarily track the field strength changes. Good luck on using base impedance to determine effiency changes! In a 40 meter test, for example, one ground system provided 35-40 ohms of feed resistance and another different system that provided almost 60 ohms of feedpoint resistance had equal field strength. I think N6RK and others have measured the same. 73 Tom - Original Message - From: DAVID CUTHBERT telegraph...@gmail.com To: Rick Kiessig kies...@gmail.com Cc: topband@contesting.com Sent: Saturday, December 15, 2012 10:49 AM Subject: Re: Topband: Optimal radial wire type and gauge? Read the N6LF radial papers and you will see that 1/8 wavelength radials are about as good as one can do. I use #14 stranded copper THHN wire because it is easy to work with. But how good can we get? For a 30' base loaded vertical I have 90 radials having an average length of 18 ft. The ground loss is 5 ohms, which is less than the loading coil loss. If I were to install 120 quarter wavelength radials I would gain 2 dB. Dave WX7G __**_ Topband reflector - topband@contesting.com ___ Topband reflector - topband@contesting.com ___ Topband reflector - topband@contesting.com
Topband: Russian 160 m contest
3830 forms are now available for the Russian 160m Contest. 73! -- С уважением, Vlad / R7LV mailto:r...@dx.ru ___ Topband reflector - topband@contesting.com
Re: Topband: GAP Vertical Question
I can think of NO earthly reason,that makes ANY electromagnetic sense to me, as antenna engineer fo placing a radial system under the end of a vertical 1/2 wave antenna - earth-worms not withstanding! ** Another case of not understanding the antenna or the purpose and handling of its current maximum. Some antenna engineer. Given that a half wave vertical has a base impedance of over 1000 ohms and a single ground rod in dirt is 100 ohms at most not a single radial is needed to obtain close to 100% radiation efficiency. Dave WX7G ** Its not the base that is the problem. The current has to be dealt with no matter where it is located on the vertical conductor or its electrical length. For want of a better word its image has to be a perfect conductor for the antenna system as a whole to be 100% efficient. It is also the current and its efficiency that determine the power radiated at the lowest angles. Excessive losses and that 10db becomes a simple glaring in your face reality. Carl KM1H - Original Message - From: Donald Chester k4...@hotmail.com To: topband@contesting.com Sent: Sunday, December 16, 2012 8:42 PM Subject: Re: Topband: GAP Vertical Question Then, why do broadcast stations that use vertical towers at approximately a half wavelength, purchase valuable real estate and spend thousands of dollars for the copper to install from 120 to 240 or more radials, each usually a half wave or more in length? See G. H. Brown: Ground Systems as a Factor in Antenna Efficiency, IRE Proceedings, June 1937 p. 753. Brown demonstrated that the distribution of earth currents and ground losses is such that the region of maximum current and loss occurs at a distance of about 0.35 wavelengths from the base of a ground mounted half wave vertical antenna, which was verified experimentally. There is zero loss at the base of the antenna itself, since there is no base current because the antenna a fed at a current node. An rf ammeter inserted in the ground lead, as well as one inserted in in the antenna lead attached to the insulated base of the radiator will read zero. The ground losses occur farther out from the base of the antenna. Low effective earth resistance provided by a good ground system is ABSOLUTELY NECESSARY for vertical antennas of ANY height if one expects good radiation efficiency. The claim that no ground system is needed for a half wave vertical is nothing more than a long-standing popular misconception. This topic prompted me to dig out and review an anecdote I recall reading in my decades-old copy of CQ magazine's Vertical Antenna Handbook, by USNR Capt. Paul H. Lee, K6TS (1974). He reported receiving mail from a ham who had made the discovery that he could tune and operate a half wave vertical without a ground system, feeding it by a parallel tuned tank circuit whose lower end is grounded. Since an rf ammeter in the ground lead showed no current, he could dispense with the ground system and its loss. He suggested to the Capt. that he should discover the new world of half verticals with no ground system. Quoting from the text (p. 84): The correspondent's claim... is true ONLY IF HE IS CONTENT TO THROW AWAY FROM 40 TO 80 PER CENT OF HIS RADIATED POWER IN THE FORM OF EARTH LOSSES. (the correspondent) stated, 'The ZL's call ME, when I use my half wave vertical!' This is not surprising, in view of the fact that the half wave's vertical pattern has a lower main lobe angle than a quarter wave would have... However, he would hit the ZL's even harder if he would put in a ground system. Of course, the half wave vertical is not dependent on a ground plane, however lossy or efficient, for the condition of RESONANCE, since it is resonant in itself because of its half wave length. However, IT IS DEPENDENT ON A GROUND PLANE FOR ITS EFFICIENCY OF RADIATION, as is any vertical antenna...' Don k4kyv Given that a half wave vertical has a base impedance of over 1000 ohms and a single ground rod in dirt is 100 ohms at most not a single radial is needed to obtain close to 100% radiation efficiency. Dave WX7G And this statement is based on what? Publications, measurements, modeling? I have built a number of 1/2 wave verticals without radials and compared them to 1/4 wave verticals with radials. They are indistinguishable in performance and certainly do not exhibit substantial ground losses AFAIK... Rick N6RK I can think of NO earthly reason,that makes ANY electromagnetic sense to me, as antenna engineer fo placing a radial system under the end of a vertical 1/2 wave antenna - earth-worms not withstanding! It's CURRENT that warms the earthworms! NOT electric field intensity! ...the ground system does NOT act as a shield from the lossy earth nor protect the earth-worms! There is absolutely NO reason to require a radial system under a 1/2 wave vertical antenna. Such an antenna will operate just fine on its
Re: Topband: Fw: GAP VERTICAL QUESTION
On 12/15/2012 7:59 AM, DAVID CUTHBERT wrote: Mike that QTH looks alot like the Great Salt Lake of Utah where I have operated a few 160 meter 'tests running a balloon vertical. Dave WX7G I learned about this QTH from Earl K6SE (SK). The terrain to the north isn't so great (high mountains), but toward CONUS is literally miles of salty lake bed. Also, it was pretty wet the year I was there (2006) which I am sure didn't hurt matters. I am glad I wasn't using a balloon antenna, however, because the winds got so bad Saturday night of the contest it broke one of the ridge poles on my little operating tent. The wind then had that broken side of the tent pinning me against the operating table :-) 73, Mike W4EF... ___ Topband reflector - topband@contesting.com
