Topband: "Low-Band-DXing"
I wish John Devoldere would come out with another, updated "Low-Band DXing" handbook. I am remembering the hours of wonderful reading. 73 Bruce-k1fz _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Re: Topband: ARRL on 1802.5 Tuesday PM
The ARRL took a survey and found that 1.802.5 MHZ would be the least problem to DX, and USA users. Many countries can only use the lower part of the band, that goes all the way up to 2 MHZ. for the USA. Hope we can all give each other a little space to enjoy the gentleman's band. Thanks, 73 Bruce-k1fz On Fri, 25 Jan 2019 13:36:32 -0500, Mark K3MSB wrote: Eh? Details? On Fri, Jan 25, 2019, 1:09 PM Charles Yahrling > And how about the ARRL encouraging AM ops to expand their use of top band > in the latest ARRL promotional email? > _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Re: Topband: Inv L improvements question
Unlike raised radials or a counterpoise...however,. Its better if the radials, if only a few, under ground are not resonant as the high impedance/ high voltage end can loose a lots of energy to ground. It is quite well known that a 'fat' (large diameter) antenna is lower Q, is wider in frequency , and depending upon physical width, is much lower impedance and voltage at the top end. Similar to the fat antenna, An 'in ground' radial field can be made 'fat' by increasing the number of radials, avoiding the resonant length, and reducing the Q. A perimeter wire around the far end of the radials can lower the impedance and voltage loss. 73 Bruce-k1fz https://www.qsl.net/k1fz/beverage_antenna.html On Sat, 19 Jan 2019 11:40:04 + (UTC), John Randall via Topband wrote: Can a radial(s) buried a couple of inches under the ground be tuned via an inductor and Can the radial all be connected to said inductor if they are the same length. Infact can it be done and is there any gain by doing this ? 73John - M0ELS _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Re: Topband: Stew Perry Contest
Sorry, it was not aimed at KH6LC, as he has very efficient antennas, but was to help all those struggling with more recent antenna problems. 73 Bruce-k1fz On Tue, 1 Jan 2019 02:59:16 +, Lee STRAHAN wrote: If I was KH6LC I would be rather offended by that comment Bruce. What does it Really mean? Perhaps not what the words really say? KH6LC has more hard work in his station than many. Lee K7TJR OR -Original Message- From: Topband On Behalf Of F Z_Bruce Sent: Monday, December 31, 2018 6:32 PM To: g...@ka1j.com; Topband Subject: Topband: Stew Perry Contest Sometimes someone will get lucky and get excellent 160 meter transmitting and receiving the first try. But most have to work at it with isolated directional receiving antenna (s), and transmitting antenna(s) de-tuned while receiving. A antenna modeling program also helps. 73 Bruce-k1fz https://www.qsl.net/k1fz/beverage_antenna.html On Mon, 31 Dec 2018 20:36:21 -0500, "Gary Smith" wrote: Yes indeed, whatever he's using is working. He copied me with my 5W signal from Connecticut, 10 miles from Rhode Island. Just got the LOTW today. That is some more than excellent copy on their part for 160M. 73, Gary KA1J > Nope, KH6LC doesn't have good ears, they have GREAT ears. Worked them > from MI with 5 watts and it wasn't the first time. HNYRuss, N3CO > > Sent from Yahoo Mail on Android > > On Mon, Dec 31, 2018 at 12:53 PM, Sam Josuweit > wrote: Worked Hawaii from NE Pennsylvania with 100 watts. Still > smiling from that one. Thanks KH6LC good ears and great patience. Too > many people give up after one or two calls. > > > > Hope everyone has a Happy and Healthy New Year. > > > > Sam(N3XZ) > > > > _ > Searchable Archives: http://www.contesting.com/_topband - Topband > Reflector > > _ > Searchable Archives: http://www.contesting.com/_topband - Topband > Reflector _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Topband: Stew Perry Contest
Sometimes someone will get lucky and get excellent 160 meter transmitting and receiving the first try. But most have to work at it with isolated directional receiving antenna (s), and transmitting antenna(s) de-tuned while receiving. A antenna modeling program also helps. 73 Bruce-k1fz https://www.qsl.net/k1fz/beverage_antenna.html On Mon, 31 Dec 2018 20:36:21 -0500, "Gary Smith" wrote: Yes indeed, whatever he's using is working. He copied me with my 5W signal from Connecticut, 10 miles from Rhode Island. Just got the LOTW today. That is some more than excellent copy on their part for 160M. 73, Gary KA1J > Nope, KH6LC doesn't have good ears, they have GREAT ears. Worked > them from MI with 5 watts and it wasn't the first time. HNYRuss, N3CO > > Sent from Yahoo Mail on Android > > On Mon, Dec 31, 2018 at 12:53 PM, Sam Josuweit > wrote: Worked Hawaii from NE Pennsylvania with 100 watts. Still > smiling from that > one. Thanks KH6LC good ears and great patience. Too many people give > up after one or two calls. > > > > Hope everyone has a Happy and Healthy New Year. > > > > Sam(N3XZ) > > > > _ > Searchable Archives: http://www.contesting.com/_topband - Topband > Reflector > > _ > Searchable Archives: http://www.contesting.com/_topband - Topband > Reflector _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Topband: Updated Beverage antenna notes
https://www.qsl.net/k1fz/beverage_antenna.html 73 Bruce-k1fz _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Re: Topband: Band Report
Hi Gary, Jeff, TZ4AM just got back, and does not have a Beverage up for NA yet. He is in a high noise area ,and receiving is difficult. 73 Bruce-k1fz On Mon, 17 Dec 2018 17:33:42 -0500, "Gary Smith" wrote: Last night around 0500Z or thereabouts, TZ4AM was coming into Connecticut at an easy 15 over 9 on the HI-Z Circle 8. I haven't heard any signal from that part of the world that strong in some years. He was working EU & Russia, didn't return to me but truly amazing signals. Maybe tonight if the conditions are duplicated. 73, Gary KA1J > Greetings Topbanders. . . > > Trees recent post commenting that "the band is in great shape" > has some truth. Conditions on topband this morning from the Midwest > (Iowa) to JA were outstanding. Conditions to at least part of VK were > also good as the VK4CT RBN had me at 14 db. . .virtually the highest > Ive seen (simultaneously Luke/VK3HJ, 1000 miles to the south, said > I was weak). Not only were conditions good but the QRN level was the > lowest Ive seen it in quite a while. While the quiet band > certainly helps S/N and pulling out the weak ones, absolute signal > levels this morning were on par with the highest so far this season. > I only worked a total of eight JA stations . . .six of which responded > to my CQs and two of which were CQing and I sought. After about 60 > minutes I finally gave up and went QRT. Five or 10 years ago these > kinds of conditions would have easily netted 15, 20, or even 30 JA > QSOs and probably a couple in Z19. Needless to say, things have > changed. > > 73. . .Dave, W0FLS > _ > Searchable Archives: http://www.contesting.com/_topband - Topband > Reflector _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Topband: Fwd: Re: Rather use N-type (was Re: The answer to PL-259 soldering/reliability problems)
Both types become quite reliable when assembled with a high degree of care. Large temperature variations/freezing can be a problem. 73 Bruce -k1fz On Fri, 7 Dec 2018 09:37:42 -0500, MU 4CX250B <4cx2...@miamioh.edu> wrote: Interesting discussion, and I appreciate the many viewpoints. One consideration, when weighing N-connectors vs PL259s, is what happens to the cable after the connector is attached. Nobody disputes that an N-Connector properly installed on, e.g. a length of Heliax running up the side of a commercial broadcast tower, will be reliable and trouble free. The manufacturer (Andrew) supplies detailed instructions and a little kit of accessories (e.g. a length of thick wall heat shrink tuning, silicone wrap, etc.) to do the job. By contrast, most coax cable connectors used by hams are attached and unscrewed many times, are flexed and yanked on and twisted, and are often installed by relatively inexperienced people using whatever tools are on hand. To me, the PL259 seems better suited for that sort of usage. Despite its flaws, it is just more tolerent of error and abuse. 73, Jim w8zr Sent from my iPhone > On Dec 7, 2018, at 7:04 AM, Bruce wrote: > > I worked in the commercial/industrial radio and broadcasting for 40 plus > years. While it it true that type-n is mostly used, we must remember that > hams deal with high power and high SWR sometimes, both are not type-N strong > points because of the small pin used in type-N can not handle the high > current caused by SWR and high power as well as the thicker pin used in a > PL259. > > 73, Bruce, W8HW > > = > >> On 12/7/2018 8:33 AM, Cecil Acuff wrote: >> That crazyI’m in the utility industry and Andrew LDF cable terminated >> with Type N connectors by the thousands, outside for years and no issues. >> Many with the old solder on type N connectors for 1/2” and more recently the >> newer simplified ring stop connectors and no problems for either. >> >> For years I was opposed to any connector that was not soldered but after 10+ >> years of using the newer no solder type connectors in just about every >> imaginable situation There have been zero problems. They sweep just as good >> as any soldered connector. The key is proper cable prep using the Andrew >> prep tools. Or if using a Times Microwave LMR cable their prep tools. The >> dimensions have to be correct. You really can’t put these things on with a >> gustimate and your pocket knife like the PL-259’s >> >> If cold weather caused a pull back it’s my opinion the center pin was >> probably recessed all along and the tiny change from temps caused it to open >> up. >> >> For Amateur use the PL-259 is not a bad connector but I rarely see them >> installed correctly either...the key problem is in the handling of the >> shield. Folding it back and screwing the connector down on it is bad >> practice and will lead to problems and possibly intermod issues. >> >> You just don’t find the PL-259 used in commercial/industrial radio >> systemsmust be a good reason. >> >> Cecil >> K5DL >> >> Sent using recycled electrons. >> >>> On Dec 6, 2018, at 11:23 PM, Guy Olinger K2AV wrote: >>> >>> I agree with Rick, >>> >>> If an N connector is not designed to fix the relationship of the center pin >>> (soldered to the center conductor) to the body it should not be used >>> outdoors or on long runs of unburied coax exposed to full seasonal >>> temperatures. >>> >>> I learned that the hard way on unfixed pin N connectors terminating 230 >>> foot runs of LDF4-50A at my tower. Of course it happened on the 40 meter >>> line on a particularly cold Saturday night in the CW SS . Had to >>> repair/resolder on the tower by flashlight in 25 degree weather. The next >>> summer after removing the up-tower flexible coax it wouldn’t reconnect >>> completely. The pin was now out too far. >>> >>> These days I am terminating my LDF4-50A with Andrew L44P UHF male >>> connectors, or dressing the cable and soldering it directly into the >>> terminating circuit. >>> >>> The male pin in a UHF connector has enough overlap with the female receptor >>> that a certain amount of temperature induced movement will no longer break >>> the connection. >>> >>> 73, Guy K2AV >>> On Thu, Dec 6, 2018 at 10:48 PM Richard (Rick) Karlquist wrote: I used to have many coax cables with factory installed type N connectors. Virtually all of them have sooner or later suffered from the center conductor pins either retracting or extending outward over time. Once the pin moves far enough either in or out, the connector will no longer mate. I have been able to temporarily rehabilitate some cables with the retraction failure by pulling on the center pin with vise grips. If they overextend, there is no way AFAIK to fix them besides replacing the connectors. Evidentally, none of these cables used connectors with a captivated cente
Topband: Vertical antennas aren't always best for DX everywhere - the facts
Hi Steve, Low band Dxers,, Some of the trials involving 5/8 wave verticals on the broadcast band, and 160 meters preformed poorly. Optimum take off angle is quite a bit higher. 73 Bruce-k1fz On Mon, 26 Nov 2018 14:56:17 +0800, "Steve Ireland" wrote: Hi Frank (and Rick) Somewhere I have a map of the lines of geomagnetic latitude superimposed on a Mercator projection of the world, but I can’t find it right now. Unlike the ruler-straight lines of conventional latitude, geomagnetic latitude lines wander across the world like a collection of snake tracks. As a result of how geomagnetic latitude snakes across the globe, a comparison can’t be directly made between similar geomagnetic latitudes in the northern and southern hemispheres – where Tom W8JI lives is probably very different to me in terms of the closeness of his geomagnetic latitude to the electron gyro-frequency. As Carl K9LA points out, the geomagnetic latitude relates to polarization and involves the ordinary and extraordinary waves that propagate through the ionosphere, and how 160m is affected by being close to the electron gyro-frequency. About 10 to 15 years ago, Carl, Nick Hall-Patch VE7DXR and Bob NM7M (SK) (also a physicist like Carl, as I’m sure you recall) helped Mike VK6HD (SK) and I to understand why our horizontal cloud-warmers outperformed efficient vertical antenna systems in SW WA. You are quite correct, the Fresnel zone where I live (the mostly far field region where ground gain is developed) has very poor conductivity. And, to repeat your point as this is not as widely known as it should be, poor Fresnel Zone conductivity has very little impact on the performance of horizontally polarized antennas, while having a major impact on vertically polarised ones. While the Fresnel (far field) zone of my location, is basically rock (granite and ‘coffee rock’), Mike’s final location beside the Kalgan estuary appeared to have much better Fresnel zone conductivity, with less rock than me and, in around half the compass directions, salt water. However, his inverted-L with an 80’ vertical section over 120 buried quarter-wave radials at Kalgan performed only marginally better than our previous attempts at vertical antenna systems did. On this basis, I came to the conclusion that the dominant problem was likely to be the geomagnetic latitude issue, rather than poor conductivity in the Fresnel zone – which it certainly is also an issue here. To investigate this further, I sought out the opportunity to operate directly by the sea here with a good vertical antenna. After much paperwork, I managed to get permission to operation from the Cape Leeuwin lighthouse, which is 40m-plus high and on a narrow finger of land surrounded by sea for over 300 degrees. In a Stew Perry TBDC in the early 2000s, with the assistance of my friend Phil VK6PH, we put up a full-sized quarter-wave wire vertical on the most seaward side of the lighthouse, less than 60 metres from the sea. This was fed against a quarter wave counterpoise and the feeder decoupled with a large ferrite choke to stop common mode effects. On the other side of the lighthouse was an inverted vee half-wave dipole. Both antennas were supported from the lighthouse balcony (at about 40m!) and detuned when not in use. An Yaesu FT-1000MP was used, running less than 100W Unfortunately conditions were poor during our evening time into North America, but at about three hours before sunrise the 160m band opened into Europe. Right from this point, the vertical was slightly down on the inverted vee by a few dB, but I would always call on the vertical first and then switch onto the inverted vee if I got no response. All the way until just after sunrise, the inverted vee outperformed the vertical, mostly raising the stations who did not hear us on the vertical. The only time this situation was reversed was when 160m started to go out as the sun started to rise and I had by then switched over to just calling stations on the inverted vee. After about five minutes of this, the Europeans I could still hear were not coming back to me anymore. Out of curiosity, I switched to the vertical – and found I could still raise a few of them. I recall vividly the last QSO with a CT1 using the vertical about 20 minutes after sunrise, exchanging 559 reports. The crazy thing is that the vertical appeared to be doing exactly what a dipole is known for doing on 160m in the northern hemisphere in some cases – extending the sunrise opening. However, this was the only time the vertical outperformed the inverted vee. As far as I know, Mike VK6HD never experienced this phenomenon when he was comparing his inverted-L quarter wave antenna against his inverted vee dipole. However, my vertical antenna was directly adjacent to the sea, surrounded by sea, which may have helped. The final event was highly interesting, but did not sway me into repeating the experiment the
Topband: Vertical antennas aren't always best for DX everywhere - the facts
Its difficult to use Geomagnetic latitude as a basis of conductivity because of variables. Robin VK6LK lived in Margaret River, Western Australia, and salt sea water was a few feet under ground. He used vertical antennas effectively. He caught rain water from his roof to storage for his drinking water. In other areas, conductive ground can be much lower from the surface to make horizontal low band antennas work best. There are areas of the earth that are sand, an insulator, and horizontal antennas can be much lower over the top surface. Makes one wonder "whats under your feet/antenna" ? 73 Bruce-k1fz https://www.qsl.net/k1fz/flag_antennas.html On Thu, 22 Nov 2018 07:40:10 -0800, "Richard (Rick) Karlquist" wrote: Holy YMMV. Thanks for your great posting of what most of us didn't know (I know I didn't). Do you have any numerical data concerning the ground conductivity in VK6 vs the VK east coast? The conductivity at my QTH is around 30mS, so obviously you are in an alternative universe by comparison. I am trying to separate out ground conductivity vs geomagnetic latitude. Isn't the VK east basically at the same latitude as VK6? It would be interesting to try a vertical on the beach on the Indian Ocean in VK6. This would presumably eliminate the ground conductivity issue, leaving only the geomagnetic stuff. 73 Rick N6RK On 11/22/2018 1:49 AM, Steve Ireland wrote: > Hi JC > > In my experience, here in the southern hemisphere and relatively close > to the equator, I wish that "Vertical TX antenna is the only way to work > DX on topband!" > > Unfortunately vertical antennas mostly don't work here well where I am > in south-western WA - there is too much ground loss in the far field and > poor geomagnetic latitude for them. > > When I lived in the UK and was G3ZZD (1971 to 1989) , I used verticals, > inverted-Ls and inverted-tees over elevated radials exclusively for > low-band DXing. It was very disappointing to find that when I moved into > the Perth Hills in 1995 and got back on 160m that verticals didn't work > like they did at my previous QTHs in the UK. > > Mystified by this situation, I contacted Dr Nick Hall-Patch, a > radio/physics scientist at a university in British Columbia, who > explained the wonders of geomagnetic lat/long to me - and pointed out at > my geomagnetic lat/long a (mainly) vertical polarised antenna might only > break even with a (mainly) horizontal antenna, even if the ground > conductivity was good. > > Mike VK6HD, who was my mentor on 160m, had learnt about the favouring of > our location for predominantly horizontal polarisation many years before > - and, after trying a raft of inverted-Ls and various ways of > shunt-loading his tower, settled on using a flat-top dipole or inverted > vee dipole as high in the air as he could get it. Independently, Phil > VK6GX (formerly VK6ABL) went a similar journey to Mike and also settled > an identical philosophy for 160m antennas. > > As outlined in my tribute on Mike's QRZ.com page, when Mike moved to his > final QTH, near Albany, on several hectares besides the Kalgan River > estuary, he finally thought he had found a location where a vertical > would work. Over about 18 months, he laid down a full-size broadcast > ground screen of 120 quarter wave radials and put up an inverted-L with > an 80 feet vertical section over it. He compared this very carefully > against an inverted vee dipole at 90', which was detuned/shorted when > the vertical was in use. > > Mike then embarked on 18 months of testing - and much to his > disappointment discovered that the inverted-L was mostly up to two 'S' > points down on the inverted vee dipole. The only times the vertical was > better was occasionally over one and half hours before sunrise - and > similarly it could sometimes be better over one a half hours after sunset. > > The good news is once in a blue moon the vertical would work better than > the dipole on long distance DX - and enabled Mike to work P4 (Aruba) and > HC. > > Almost entirely the rest of Mike's 260+ countries on 160m were worked on > flat-top or inverted vee dipoles. > > After another year or so, Mike quietly took the inverted-L down - and > concentrated instead on improving his 160m reception through the use of > Beverage antennas. > > For many years, Mike and I were treated by several knowledgeable 160m > DXers as being either incompetent or deluded about a simple horizontal > cloud warmer being better than a vertical in south-western WA. I used > to get angry about it, but Mike (who was older and wiser) would just > laugh and say let those in the rest of the world have their own beliefs > about what actually happens where we live. > > If the books in English on 160m antennas and operating had been written > in VK6, rather than in high latitude USA and Europe, they would say very > different things about verticals, along the lines of: "Don't torture > yourself." ;-) Note also that verticals seem to work just
Topband: Impedance of inv l?
Correct Rob, Things are sometimes the reverse of what they initially seem to be. When I was a very young kid I watched workers put in telephone poles, then put wire lines on them. I knew the poles supported the wires. Later another kid said the wires hold up the poles. I disagreed, but he got me wondering. About a year later a fast driven car hit a pole and knocked out about 6 feet of pole at the bottom, and the pole was suspended by the wires. This got me wondering for some time. Its well known the current does most of the radiating. Voltage/impedance at the top of a vertical can be minimized by going to a fat antenna to maximize current radiation. But the vertical needs something to work against. Salt water is great, but otherwise most DXers go for an efficient radial field. Lower restive loss to the radials, the less power loss occurs. A matching network can change this low resistance (impedance) to that of your coax. 73 Bruce-K1FZ https://www.qsl.net/k1fz/beverage_antenna.html On Mon, 19 Nov 2018 09:58:31 -0600, Rob Atkinson wrote: My inv. L is 50 feet up and 70 horizontal. Wire is #14 bare 7 strand hard drawn. 3 feet out from mast. 101 radials, two ground rods and aluminum siding on garage strapped in to ground sys. on around 1840 Z is 11 R and ~ 20 ohms X. A typical inverted L with a good ground system should be down around 15 ohms at feedpoint from my experience and rapidly change above and below the minimum reactance point. High resistance flat antennas have an inadequate ground system. Rob K5UJ _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Re: Topband: Impedance of inv l?
The far end is high impedance voltage, and has minimum horizontal current radiation. The inverted L is a good trade off signal vs available height. Not an expensive antenna to build. 73 Bruce-k1fz On Sun, 18 Nov 2018 12:31:38 -0700, Wes Stewart wrote: That also drives up the current in the horizontal wire with attendant increased horizontal radiation. I chose for a couple of reason to do the opposite; shorten the wire to make the feedpoint capacitive and use a shunt inductor to get a 50-ohm match. This really doesn't improve the 2:1 VSWR, that I consider acceptable, however. Wes N7WS On 11/18/2018 8:55 AM, F Z_Bruce wrote: > That sounds about right. As you put a good ground system under it, that value will come down, and the efficiency will come up. > > Many add extra antenna wire that pushes the current up the wire, this also raises the impedance, hopefully to near 50 ohms with the right length. > A capacitor (variable, then fixed) in series at the feed point can cancel the added inductance. > > 73 > Bruce-k1fz > https://www.qsl.net/k1fz/beverage_antenna.html > > > On Sun, 18 Nov 2018 10:41:36 -0500, WW3S wrote: > > What should the Z be for a 1/4 wave inv l, with the radials attached to a radial plate? Mine seems to be 60 ohms or so > > Sent from my iPad > _ > Searchable Archives: http://www.contesting.com/_topband - Topband Reflector > > _ > Searchable Archives: http://www.contesting.com/_topband - Topband Reflector > _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Topband: Fwd: Re: Impedance of inv l?
Original Message Subject: Re: Topband: Impedance of inv l? Date: Sun, 18 Nov 2018 10:55:47 -0500 From: F Z_Bruce To: w...@zoominternet.net, Topband That sounds about right. As you put a good ground system under it, that value will come down, and the efficiency will come up. Many add extra antenna wire that pushes the current up the wire, this also raises the impedance, hopefully to near 50 ohms with the right length. A capacitor (variable, then fixed) in series at the feed point can cancel the added inductive reactance. 73 Bruce-k1fz https://www.qsl.net/k1fz/beverage_antenna.html On Sun, 18 Nov 2018 10:41:36 -0500, WW3S wrote: What should the Z be for a 1/4 wave inv l, with the radials attached to a radial plate? Mine seems to be 60 ohms or so Sent from my iPad _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Re: Topband: Impedance of inv l?
That sounds about right. As you put a good ground system under it, that value will come down, and the efficiency will come up. Many add extra antenna wire that pushes the current up the wire, this also raises the impedance, hopefully to near 50 ohms with the right length. A capacitor (variable, then fixed) in series at the feed point can cancel the added inductance. 73 Bruce-k1fz https://www.qsl.net/k1fz/beverage_antenna.html On Sun, 18 Nov 2018 10:41:36 -0500, WW3S wrote: What should the Z be for a 1/4 wave inv l, with the radials attached to a radial plate? Mine seems to be 60 ohms or so Sent from my iPad _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Re: Topband: Fwd: Re: VE1ZZ Nite
Many VE1ZZ contest possibilities, maybe similar to "Stew" contest , "Jack ZZ " could work. RIP Jack 73 Bruce On Sat, 20 Oct 2018 14:10:13 -0400 (EDT), JL PFIRMAN wrote: Tree looks like a lot of top banders are in favor,its your club.To bad his call can"t be retired like other sport numbers thanks much, Jim W3TO Original Message -- From: Tree To: w3t...@comcast.net Cc: 160 Date: October 20, 2018 at 10:59 AM Subject: Re: Topband: VE1ZZ Nite We could rename the PreStew (which starts in one minute). Tree On Sat, Oct 20, 2018 at 6:42 AM JL PFIRMAN < w3t...@comcast.net mailto:w3t...@comcast.net > wrote: God rest your soul Jack,may His Perpetual Light Shine upon you. To All,we have the" Stew " ,how about the "Jack"on the yearly anniversary of his death? No logs to send in,just an evening on top band ,cw or ssb ,your choice."eh". 73 RIP Jack . Jim W3TO _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Re: Topband: Historical note: Radial Depth
AM radio stations did and still do have to meet field strength readings at contour data points. (.Ground wave field strength way point readings.). Directional antennas had to be carefully maintained. to protect stations operating on the same frequency at some distance. Radials on the earth surface are more subject to change than buried ones.. 73 Bruce-k1fz https://www.qsl.net/k1fz/bognotes.html Don't forget that historically many if not most broadcast stations, plus the legendary work of Brown, Lewis and Epstein, had their radials in farm fields and cow pastures, where anything on or near the top of the ground would be destroyed. Terry N4TZ _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: WD1-A as radials
The new liquid tape works very well to keep moisture out of the ends. It is sold under the name of "liquid tape", and also "Brush on" liquid tape.. It surrounds each wire strand when applied generously. 73 Bruce-k1fz On Wed, 10 Oct 2018 14:49:50 + (UTC), Eduardo Araujo via Topband wrote: We has been using WD1-A since a few years, we split it in two and seal the remote end to minimize moisture or water entrance. When the ground is under water (flooded) for some days, even being the plastic strong, it deteriorates faster. If the terrain doesn't flood, it last some years Regards to all Eddie, LU2DKT On Wednesday, October 10, 2018, 10:34:10 AM GMT-3, Nathan Moreschi via Topband wrote: I've used it for radials with good success in the past. I have had some issues with it rusting as time progressed but nothing too bad. And yes, it is very strong. I've used the twisted pair (doubled up) as guys for masts and small aluminum towers with light loads with no problems. 73, Nate/N4YDU On Wednesday, October 10, 2018, 9:24:12 AM EDT, Roger Parsons via Topband wrote: I think that WD1-A would be perfect for on-ground radials. (Note that WD1-A is not twisted although WD-1 is.) It lays very flat on the ground, the critters don't like it, and it is immensely strong. I always use crimp terminals but YMMV. I don't think it matters either way whether you use one or both wires - for Beverages I always use both wires but connected separately. That way I can use a simple ohmeter test to confirm that the whole length is continuous. 73 RogerVE3ZI _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: Beverage F/B using oscillator
With the BOG it is not very variable/ if any..(it does vary with conductivity of the soil) (consider sand as non-conductive) The Beverage can be tilted somewhat, however its not" one size fits all". Low angle signal signals are not affected, high angles somewhat. (end height affect end impedance) At one location very low angle neighborhood noise may be worse. Decide what you want and computer model it 73 Bruce-k1fz On Tue, 9 Oct 2018 15:34:15 +0200, wrote: Additional question; with respect to the BOG/Beverage backlobe upwards angle, does the test-generator antenna need to be lifted from local groundlevel by say 2- 10m? Or can this test be done just as reliable on groundlevel? 73 Mark, PA5MW -Original Message- From: Topband On Behalf Of F Z_Bruce Sent: Tuesday, October 09, 2018 3:01 PM To: ash.kf5...@gmail.com; Topband Subject: Topband: Beverage F/B using oscillator Good information. Finding the best BOG F/B. I use an model MFJ-5014 white noise generator off the 'back' of the BOG antenna. Then tune the receiver to find the 'minimum noise' signal frequency.Adjust the BOG antenna length to bring it into 160 meters.. Care must be taken not to create a neighborhood noise problem. 73 Bruce-k1fz On Tue, 9 Oct 2018 09:07:42 +0100, Ashraf Chaabane wrote: Hi All, I used a 1.843 oscillator to check NA beverage F/B. The mesurements were taken 160m away from each end of the antenna. Noise level was constant. I had 4 dB difference between front and back signals. Is that what I should expect? Is 1 wavelength distance enough to do this experience? This will be repeated with different terminations and I want to make sure I'm doing it correctly. It will also be applied on the newly installed BOG to determine optimum length. Tnx and see you on the air! -- Ash ~ 3V8SF Topband: *http://www.kf5eyy.info/topband.htm * Phone/SMS/Whatsapp: (+216) 22670026 Skype: kf5eyy _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband
Topband: Beverage F/B using oscillator
Good information. Finding the best BOG F/B. I use an model MFJ-5014 white noise generator off the 'back' of the BOG antenna. Then tune the receiver to find the 'minimum noise' signal frequency. Adjust the BOG antenna length to bring it into 160 meters.. Care must be taken not to create a neighborhood noise problem. 73 Bruce-k1fz On Tue, 9 Oct 2018 09:07:42 +0100, Ashraf Chaabane wrote: Hi All, I used a 1.843 oscillator to check NA beverage F/B. The mesurements were taken 160m away from each end of the antenna. Noise level was constant. I had 4 dB difference between front and back signals. Is that what I should expect? Is 1 wavelength distance enough to do this experience? This will be repeated with different terminations and I want to make sure I'm doing it correctly. It will also be applied on the newly installed BOG to determine optimum length. Tnx and see you on the air! -- Ash ~ 3V8SF Topband: *http://www.kf5eyy.info/topband.htm * Phone/SMS/Whatsapp: (+216) 22670026 Skype: kf5eyy _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: Inv L in Tree
Its mostly about doing what you can with what you have with local conditions that exist. WD-1A is very strong , difficult to see, and the loss is not all that bad, so it can be a good choice sometimes. In the early days of this reflector there was mid-western DXer that moved to a neighborhood with rows of close houses. Well after dark he ran a BOG antenna often down the lawns of his neighbors, then picked it up before anyone awoke for the day. Had a few close calls but , got a lot of DX. There was a tale of a DXer in a skyscraper of New York city that used the apartment copper plumbing for his ground and a wire down the plastic sewer line for his antenna. In NYC, I sold a BOG transformer to a resident that ran the "on ground wire" down an alley between tall buildings. I have no idea how he achieved a ground, but he said he worked DX, but did give specifics. As they used to say "hang in there and have fun" ! 73 Bruce-k1fz On Thu, 4 Oct 2018 21:56:20 +1000, vk3io wrote: Hi Brian and others. Brian should have added with his comment, that he has made numerous qso's to VK (that is with me and other VK's) with his "poor antenna" on top band overs the past years and when and if he can move the wire away from the tree trunk, then he will no doubt make many more qso's. What a difference one S point can make or even a half an S point, when you move the wire away from the tree, by 2 or 3 feet, if possible. When I consider the number of dx qso's I "almost made" over the past 30 years or so, on Top Band and what I could have worked, if only for one S point, on TX and or RX. If only I had the drive or time to make such a small improvement to my antenna system. Cheers from Ron, vk3io. On 04-Oct-18 9:22 PM, Brian Campbell wrote: > Ed, Gary and All, > > Seeing as I have had my Inverted L ( 85' / 27M vertical ) against my tree's > trunk ( actually touching it - oops ) since I installed it, and as I also > have tress in the elbow, I may have to try and move it out some after reading > all the suggested articles. The only reason it is like it is, is for > convenience, as I have no towers ( or trees in the right location ) to hang > it off of atm so it was either that or no Inverted L. > > All I can and will say is that just "anecdotally" speaking and nothing else, > it will still work, not as good as one that is stood off a few feet I am sure > but better than nothing if it gets you on the air. Or to put it another way, > a poor antenna is much better than no antenna at all. > > Good Luck and remember YMMV > > 73, > Brian > VE3MGY > > > > > > > > From: Topband on behalf of Gary Smith > Sent: October 3, 2018 9:27 PM > To: Topband@contesting.com > Subject: Re: Topband: Inv L in Tree > > Ed, > > FWIW, I'm using what used to be an INV-L. > I laid out a radial bed as well as > possible, next to a marsh. I am in a > hurricane area and with the winds, the > trees have fallen over. I originally shot > a line over a tall branch with a spud gun > I made (see it on my QRZ page, at the > bottom), at that time it was an "L". > > The branch came down and I used another > branch, albeit farther away. With > attrition, I am now using a tree maybe 30' > away from straight up. Doing it the way I > did allows me to have a radial bed away > from the trunk of a tree. I can't move the > bed so the type of antenna had to change. > I am using WD-1A field telephone wire for > my antennas, with its SS solid core it is > incredibly strong and it is so thin it is > very hard to see. > > It's not nearly as good of an antenna as > many here use but it is quite good, even > as a sloper. I was able to work 9X0T on > 160 tonight and could barely hear him with > the QRN & RFI but he heard me. Point being > that a sloper works very well on 160, you > don't "have to have" an INV-L. > > Whatever you go with, I wouldn't run the > antenna next to the trunk. I would keep it > some distance to the trunk and as long as > you have enough length for radials & > antenna & I'd use some method of getting a > stealthy wire like WD-1A up over & into > the tree-top and down to the radial plate. > > 73, > > Gary > KA1J > >> Has anybody snaked a wire up a tall tree trunk to make an Inv L? >> >> Any interaction? Success?? Has to be stealthy because the tree os >> my neighbor's :-) >> >> Thanks, >> Ed NI6S >> _ >> Topband Reflector Archives - http://www.contesting.com/_topband >> > > > > _ > Topband Reflector Archives - http://www.contesting.com/_topband > _ > Topband Reflector Archives - http://www.contesting.com/_topband > _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: Use shunt fed tower
Depends upon the concrete/cement . ( Base fed vertical) Years ago, found after experimenting with out base insulators that there were definite high RF losses. (resistance went through to earth) 73 Bruce-k1fz https://www.qsl.net/k1fz/bognotes.html . On Sun, 16 Sep 2018 20:26:02 -0400, Stan wrote: Hi everybody! A couple thoughts on shunt fed towers... Depending on what you read on the web, concrete/cement might (or might not) be somewhat of a conductor. So, could attaching to concrete around the house be a help as a ground/radial? Thoughts??? Feeding a tower with NO RADIALS. It seems it would be possible to feed a tower about halfway up as a center fed vertical dipole, with no need for radials. In most cases it would be a very short dipole for Top Band, tho. Thoughts??? Sometimes weird ideas pop into my head.. Stan K8LL 10-10# 76801 FP# 3255 Propagation is our master... but sometimes the master is cruel! _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: Use shunt fed tower
Steve, Think you are doing a great job considering the lot size.Never know what else is in the mix. The power line neutral (ground) may. be helping Someone years ago fastened to a metal sewer line. 73 Bruce-k1fz https://www.qsl.net/k1fz/beverage_antenna.html On Sat, 15 Sep 2018 19:36:13 -0700, Steve Lawrence via Topband wrote: 217 DXCC 36 Zones. Shunt fed tower. No radials. West Coast city lot. I can only imagine my totals if it really worked. 73 Steve WB6RSE > On Sep 15, 2018, at 5:42 PM, John Harden, D.M.D. wrote: > > A shunt fed tower requires radials period. It cannot work without them! > > 73, > > John, W4NU > > Sent from my iPhone > >> On Sep 15, 2018, at 1:55 PM, wrote: >> >> It makes no difference how the tower is fed, a vertical antenna must have >> radials of some kind to be effective. 73. . .Dave, W0FLS >> >> -Original Message- From: cfytech24x7 >> Sent: Saturday, September 15, 2018 11:29 AM >> To: topband@contesting.com >> Subject: Topband: Use shunt fed tower >> >> A shunt fed tower is a vertical antenna so it offers lowest take off angle. >> Shunt feeding avoids need for radial field. Any horizontal wire antenna is >> going to put most of your radiated energy out at high angles, unless you can >> get it at least a half wavelength of height. A loop may be a quieter >> antenna for RX but your existing inverted Vs are no doubt better for TX. >> There is some art and experimentation involved in the matching but the >> results will be worth the effort. I would start with your highest antenna >> for top band, next highes for 80m. Note that your yagis will act nicely as >> capacitive hats to add to effective tower hight. >> Gl es 73, ab1vl chuck >> >> >> >> >> Sent from my Galaxy Tab® A >> _ >> Topband Reflector Archives - http://www.contesting.com/_topband >> _ >> Topband Reflector Archives - http://www.contesting.com/_topband > > _ > Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband
Topband: Fwd: Sky Glow
Will the sky glow called "STEVE" benefit low band propagation ? It remains to be found. https://www.livescience.com/63385-steve-not-aurora-mystery-phenomenon.html 73 Bruce-K1FZ _ Topband Reflector Archives - http://www.contesting.com/_topband
Topband: Topband
Watching 160 meters activity on DX-watch. Noting a gradual increase of DX postings . Propagation to TX5T looks good to many areas.. 73 Bruce-K1FZ _ Topband Reflector Archives - http://www.contesting.com/_topband
Topband: Fwd: Re: Baker Island DXpedition on 160
As in ARRL literature, even as short antenna in a great ground plane can be very effective. The Baker Island group has indicated that they were going to use the salt water.. 73 Bruce-k1fz On Wed, 13 Jun 2018 16:14:01 +, jon jones wrote: Back in the 90's - KH6ND was active from Kure Is on 160M during July. He was very workable in North America in the early morning hours before NA sunrise. I logged Mike with 100 w and my balloon supported vertical. QRN from thunderstorms may be lower at that time. Europe may well have some short windows of opportunity as well. A safe trip to the KH1/KH7ZZ team. - Jon N0JK Hello TopBanders, KH1/KH7Z will be active on 160 from Baker Island from June 27 to July 6 (note that dates are tentative and may change -- please visit http://baker2018.net/ for updates). GL and CU, George, AA7JV PS: Donations are the life-blood of DXpeditions and this one is no exception. _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: Propagation on 160
Hi Ash, Propagation is very poor and noise is high this particular period of time. Your Beverage is probably OK. http://www.qsl.net/k1fz/beverage_antenna.html 73 Bruce-k1fz On Wed, 30 May 2018 09:59:38 +0100, Ashraf Chaabane wrote: Hi All, I set up a 260m long beverage beaming NA back in March. The height from ground was 1m. It performed well (RBN spots of US stations). I dismantled it then re-installed it two weeks ago at 2m high. But I almost can't have any US station reported. Is it a matter of poor propagation these days? (Sorry, I can't monitor the band for entire nights). Does this have to do with my beverage height? When I filter NA/EU RBN sport, I don't find many spots. Beverage details: http://www.kf5eyy.info/technical.htm 73 -- Ash ~ 3V8SS/KF5EYY http://www.kf5eyy.info/ Phone/SMS/Whatsapp: (+216) 22670026 Skype: kf5eyy _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband
Topband: Cores on Beverage antennas.
A good reference for Beverage antenna length is by W3LPL, Search online for his patterns, F/Binfo. If a shorter Beverage wire length is used because of space restrictions,a near perfect feed and restive termination can appear as a low VSWR, over a reasonable frequency range. However here in Maine, the ground is typically not close to level in elevation , and with variations in soil conductivity, resonant lengths are beneficial.. One of the ways to make a wire look electrically longer is the use of covered wire. (Velocity factor that can vary with type of covering used). Also some have placed small lumped inducatances along the way,, Another used a slinky.. Basic understanding about cores that most, excepting mix 33, are inductive, So have a question for anyone who has tried it. Will adding many mix, 43, and 77 spaced cores with a few turns each along the Beverage wire , lower the basic frequency enough to be beneficial? 73 Bruce-K1FZ http://www.qsl.net/k1fz/beverage_antenna.html _ Topband Reflector Archives - http://www.contesting.com/_topband
Topband: Aurora
"STEVE" Follow up address https://www.space.com/39968-steve-aurora-mystery-explained.html 73 Bruce-k1fz _ Topband Reflector Archives - http://www.contesting.com/_topband
Topband: "Steve" Aurora phenomenon
Google News Science section has interesting information about "meet Steve" , A new part of the Aurora. Check it out. 73 Bruce-K1FZ _ Topband Reflector Archives - http://www.contesting.com/_topband
