Re: Topband: Location of beverage close to 60 ft hill
Go for it. I live in the middle of the Appalachians and my Beverage wires go up and down many hills and valleys and cross many ravines and work great. On their worst day they still hear things my TX vertical couldn't hear on its best day :) > Comments Please 1. Why the need to keep it 300' from the inverted L? You can read a lot about how they should be far apart, but (outside of multiband contest stations where one radio is trying to listen on the Beverage while another is transmitting) it may not be so important in practice. I will explain my experience... A few years ago I put up 580' Beverage antennas for NW, NE, SE, and SW. I read that they should be far from the TX antennas, so the closest point from any of those RX antennas to any TX antenna is about 1000'. To cover the "missing" directions, I put up a 4 square receive antenna from a popular manufacturer. But, I found that the Beverage antennas were (usually, but not ALWAYS) better than the 4 square even in its favored directions. So, I decided to put up Beverages for N, E, S, and W also. N and S were no problem. But, when it came to E and W there was an issue. All of my Beverage antennas are installed on my neighbors property. It is 32 acres (surrounded east through west by 1.6 million acres of national forest!) but very "long". It is about 400' wide by about 3200' long with an odd triangle shape at the far end, all pointed slightly northwest. I am on the west side of that property. A 580' East/West Beverage would just not fit on his property unless I put it in that odd triangle area at the end, which was about 2500' from my house! Alternatively, I could put it in the area where his property and my property lined up. That would give me 800' E/W to work with, but it would mean that the Beverage would come within 100' of my TX vertical (and the miles upon miles of radial wires that lay on/in the ground around them). I consulted my friend and antenna mentor Frank, W3LPL. Frank suggested that I first put up the E/W Beverage where it was close to the TX vertical. If the noise wasn't any louder than it was on the other 6 Beverage directions it was fine. Otherwise, he recommended going the 2500' away route. I did as he suggested and it turned out to be just fine. My E/W Beverage, which runs within 100' of my 160m TX vertical and 80m vertical array, doesn't have any more noise than the other 6 directions whose combined closest point is 1000' away from the TX antennas (the furthest points are much further!) The S/N ratio on the E/W antenna is not discernibly different than the other 6 directions. If I were a multi-band (multi/multi or SO2R) contest station I suspect I would have issues trying to listen on that antenna while transmitting. But, for DXing purposes, it works very well. It is worth noting that this antenna merely "passes by" one or more TX verticals within 100'; the feedpoint is several hundred feet from any TX vertical and doesn't line up with the base of any TX vertical in a targeted direction. 2. You said your target was EU and AF. I have found (from southwestern VA where the bearings aren't much different than they are in MD) that an EU Beverage and an AF Beverage are two different antennas. At least with 580' antennas, 45 degrees is great to EU and northern AF while 90 degrees is great to central/southern AF (and ok to northern AF). A 580' Beverage pointed at EU won't hear central and south AF very well. If you can do two, I'd recommend one at 45 degrees and one at 90 degrees. If not, I'd recommend one at 60 degrees. 73, Tom NI1N -Original Message- a. cross a 8 ft wide stream b. run about 10-15 ft up a bank behind my house Jim WA3MEJ ___ UR RST IS ... ... ..9 QSB QSB - hw? BK
Topband: Dimensions of K2AV folded counterpoise
Hi Guy Your folded counterpoise idea sounds excellent. About 12 years ago, I built a miniature quad antenna for 7MHz that used folded capacitive loading to make two elements, each with sides around 20', using techniques pioneered by G3FPQ. During the course of this experimentation, I learnt that it was possible to make relatively low-loss capacitive loading using folded wires (bent back on themselves) if a minimum spacing was observed. The miniature 40m quad antenna, mounted at 20 metres high, was a very effective antenna. At 7MHz, this minimum spacing transcribed to about 0.005 of a wavelength, or about 9 inches (23 cm). Scaling this up to 1.8MHz, this gave a spacing of about one metre between the folded wires and I built my late father Ossie G0TYJ a very effective folded 160m antenna and counterpoise that fitted into a very small space, using this technique. I would be very interested - as am sure other users of this reflector would be - on what spacing you use between the folded wires on your counterpoise system. If you have found you can use a spacing of less than a metre between the wires, this would be good news to myself and others! One metre spacing was rather cumbersome. Vy 73 Steve, VK6VZ (ex-G3ZZD) --- Guy, K2AV wrote: SNIP >Remember that the current entering the FCP is set by the radiating wire because the apparent series resistance in the FCP is so low relative to the radiation resistance of the vertical radiator. The FCP's beginning current would be the same amplitude as the beginning current on the two radials. Set our imaginary power drive to get one ampere at the base of the antenna in both cases. Counting FCP segments 1 through 5. 33 feet per segment. Directions used are for illustration only. 1: center to 33 feet east 2: 33 feet east back to center 3: center to 33 feet west 4: 33 feet west back to center 5: center to 33 feet east and end insulator. Segments 2 through 5 carry the typical cosine current curve of a 0 to 90 degrees quarter wavelength. This is enforced working backward from the end insulator. Segment 1 has the cosine of -22.5 degrees to 0 degrees. The current max is at the connection between segments 1 and ___ UR RST IS ... ... ..9 QSB QSB - hw? BK
Re: Topband: Another non-traditional antenna working.
Guy Olinger K2AV wrote: > Counting FCP segments 1 through 5. 33 feet per segment. Directions > used are for illustration only. > > 1: center to 33 feet east > 2: 33 feet east back to center > 3: center to 33 feet west > 4: 33 feet west back to center > 5: center to 33 feet east and end insulator. Your analysis IMHO doesn't take into account coupling between the two conductors in the open wire line. I would characterize the above as a 33 foot radial in series with two 33 foot shorted stubs. A 33 foot shorted stub made of 600 ohm line is equivalent to about 20 microhenries of inductance. Two of those add up to 40 microhenries. This is close to the 55 microhenry loading coil you mentioned. Using a shorted stub of OWL to implement an inductor is an implementation decision. It seems less lossy because it doesn't get hot; the heat is spread out over a large area. But you still have the copper losses of a considerable length of wire which add up to a similar amount of loss that a big coil would have. You're probably right that it's cheaper than a coil, at least if you buy it new. Again, nothing wrong with doing this; I'm sure it works, but there is nothing magic going on here. It sounds like a nice ham-proof implementation of short elevated radials, which can be tricky to install the usual way. I don't see how any of this improves bandwidth except to the extent it adds loss to the system. There is a known relationship between antenna size, bandwidth and efficiency. Networks on the ground don't fundamentally affect this. Replacing an inductor with a shorted stub is always detrimental to bandwidth because the inductance of the shorted stub is proportional to frequency, instead of constant like the inductor. Rick N6RK ___ UR RST IS ... ... ..9 QSB QSB - hw? BK
Re: Topband: Another non-traditional antenna working.
Guy, > The junction of the FCP and vertical radiator is driven with a 1:1 > isolation transformer (required) between it and coax center conductor, > coax shield, and any connection to ground. Why is an isolation transformer required and not a simple tapped or series (as appropriate to the impedance of the vertical element) coil with a high quality common mode choke? > Counting FCP segments 1 through 5. 33 feet per segment. Directions > used are for illustration only. > > 1: center to 33 feet east > 2: 33 feet east back to center > 3: center to 33 feet west > 4: 33 feet west back to center > 5: center to 33 feet east and end insulator. What is the spacing between each "fold"? We know the FCP takes 66 linear feet but what about the transverse direction? Why only five segments? Why not six with length adjustment to provide more complete cancellation ... or a bidirectional FCP where each "side" provides complete cancellation for the other? 73, ... Joe, W4TV On 11/16/2011 10:12 PM, Guy Olinger K2AV wrote: > Hi Rick, > > We need to look at the current distribution and amplitudes on a 5/16 > wave single wire folded counterpoise (FCP) quite carefully. It really > is NOT the same as two loaded 1/16 wave radials. > > The deciding factor between the two is definitely not appearances. > When an FCP is either naturally in black or spayed with black, brown > and green against a background of trees or woods, our experience is > that it becomes invisible from the street, even when you know it's > there and where it is, actually up to HOA stealth levels. But > significantly more critical than that, if you really understood the > camouflage FCP's "Christine-approved" seal of approval both in nature > and depth of criticism, you would not propose appearance as a deciding > factor for two 1/16 radials. You'd be back to performance issues. > :>) > > Just in general, if two loaded 1/16 wave radials were as good as the > experience we have had with the FCP, two loaded sixteenth waves would > have already been out there in number, tons of folks happy as a pig in > slop using it, it would be in ON4UN's book and we would not be having > this discussion. Even with the single inductor for both radials, a > pair of 1/16 radials requires something like a whopping 55 > microhenries to tune it, and with a lossless coil has a 1.5:1 SWR > bandwidth of only 26 kHz. The coil required is almost all of a $70 ten > inch B&W #3026 Miniductor if you want to run QRO. Myself, the last > time I tried to do something that extreme I melted the plastic rods > with overheating. > > The smallest successful radial set I have seen is ON4UN's proffer of 4 > loaded 1/8 wave elevated radials, which is in use with good results at > one active contest station in my local area. John's radial length and > count choice, to my analysis anyway, seems a carefully chosen balance > between the loading inductor's size and losses, and narrowing of > bandwidth, and the loss multiplier of length over ground. But that > requires the 90 foot square for the radials, vs. the 66 foot line for > the FCP. > > The FCP is not a shortened counterpoise like a pair of 1/16 radials. > The FCP is a LENGTHENED counterpoise, LONGER than than a quarter wave > in order to pull off a field cancellation trick by folding it. It > also has a useful side effect of moving a typical tuned resonant Z of > smallish vertical radiator plus counterpoise above 50 ohms. > > The junction of the FCP and vertical radiator is driven with a 1:1 > isolation transformer (required) between it and coax center conductor, > coax shield, and any connection to ground. A wind, rain and snow > static ground is provided by a 10 watt 5 meg resistor bridging the > windings which is the only connection between the two windings. The > length of the radiating wire is adjusted at the far end to present > zero reactance on the shack side of the isolation transformer. This > way the residual inductance of the isolation transformer and the > capacitive reactance of the FCP is soaked up in the pruning and > tuning. Back to the current distribution... > > Remember that the current entering the FCP is set by the radiating > wire because the apparent series resistance in the FCP is so low > relative to the radiation resistance of the vertical radiator. The > FCP's beginning current would be the same amplitude as the beginning > current on the two radials. Set our imaginary power drive to get one > ampere at the base of the antenna in both cases. > > Counting FCP segments 1 through 5. 33 feet per segment. Directions > used are for illustration only. > > 1: center to 33 feet east > 2: 33 feet east back to center > 3: center to 33 feet west > 4: 33 feet west back to center > 5: center to 33 feet east and end insulator. > > Segments 2 through 5 carry the typical cosine current curve of a 0 to > 90 degrees quarter wavelength. This is enforced working backward from > the end insulator. Segment 1 has
Re: Topband: Another non-traditional antenna working.
Rick: Just to confirm what Guy mentioned regarding the visual impact of FCPs... They can truly be made virtually invisible from a distance even when a person knows where to look. I know this for fact because N3ND and I did the camouflage paint job on his FCP just two weeks ago. The method we used was similar to how I hide my 43' Rohn 25 among rows of pines at my QTH. Years and years ago we did the same thing in Vietnam during the war in order to camouflage aluminum and fiberglass antenna masts so Charlie and NVA Regulars had a more difficult time putting us off the air. It is easy to do if the rules of nature are maintained - no straight lines... A camouflaged FCP truly is a thing of beauty to behold and also to use on Top Band, I know because I use one (hi hi) Mine is hidden in the woods no need for spray paint but from a distance it doesn't stand out as even being there... Hi Rick, We need to look at the current distribution and amplitudes on a 5/16 wave single wire folded counterpoise (FCP) quite carefully. It really is NOT the same as two loaded 1/16 wave radials. The deciding factor between the two is definitely not appearances. When an FCP is either naturally in black or spayed with black, brown and green against a background of trees or woods, our experience is that it becomes invisible from the street, even when you know it's there and where it is, actually up to HOA stealth levels. But significantly more critical than that, if you really understood the camouflage FCP's "Christine-approved" seal of approval both in nature and depth of criticism, you would not propose appearance as a deciding factor for two 1/16 radials. You'd be back to performance issues. :>) Just in general, if two loaded 1/16 wave radials were as good as the experience we have had with the FCP, two loaded sixteenth waves would have already been out there in number, tons of folks happy as a pig in slop using it, it would be in ON4UN's book and we would not be having this discussion. Even with the single inductor for both radials, a pair of 1/16 radials requires something like a whopping 55 microhenries to tune it, and with a lossless coil has a 1.5:1 SWR bandwidth of only 26 kHz. The coil required is almost all of a $70 ten inch B&W #3026 Miniductor if you want to run QRO. Myself, the last time I tried to do something that extreme I melted the plastic rods with overheating. The smallest successful radial set I have seen is ON4UN's proffer of 4 loaded 1/8 wave elevated radials, which is in use with good results at one active contest station in my local area. John's radial length and count choice, to my analysis anyway, seems a carefully chosen balance between the loading inductor's size and losses, and narrowing of bandwidth, and the loss multiplier of length over ground. But that requires the 90 foot square for the radials, vs. the 66 foot line for the FCP. The FCP is not a shortened counterpoise like a pair of 1/16 radials. The FCP is a LENGTHENED counterpoise, LONGER than than a quarter wave in order to pull off a field cancellation trick by folding it. It also has a useful side effect of moving a typical tuned resonant Z of smallish vertical radiator plus counterpoise above 50 ohms. The junction of the FCP and vertical radiator is driven with a 1:1 isolation transformer (required) between it and coax center conductor, coax shield, and any connection to ground. A wind, rain and snow static ground is provided by a 10 watt 5 meg resistor bridging the windings which is the only connection between the two windings. The length of the radiating wire is adjusted at the far end to present zero reactance on the shack side of the isolation transformer. This way the residual inductance of the isolation transformer and the capacitive reactance of the FCP is soaked up in the pruning and tuning. Back to the current distribution... Remember that the current entering the FCP is set by the radiating wire because the apparent series resistance in the FCP is so low relative to the radiation resistance of the vertical radiator. The FCP's beginning current would be the same amplitude as the beginning current on the two radials. Set our imaginary power drive to get one ampere at the base of the antenna in both cases. Counting FCP segments 1 through 5. 33 feet per segment. Directions used are for illustration only. 1: center to 33 feet east 2: 33 feet east back to center 3: center to 33 feet west 4: 33 feet west back to center 5: center to 33 feet east and end insulator. Segments 2 through 5 carry the typical cosine current curve of a 0 to 90 degrees quarter wavelength. This is enforced working backward from the end insulator. Segment 1 has the cosine of -22.5 degrees to 0 degrees. The current max is at the connection between segments 1 and 2. Distributed current on segment 2 is the mirror image of distributed current on segment 1. Segment two is reverse current direction from segment one, therefore segments one and
Re: Topband: Another non-traditional antenna working.
Hi Rick, We need to look at the current distribution and amplitudes on a 5/16 wave single wire folded counterpoise (FCP) quite carefully. It really is NOT the same as two loaded 1/16 wave radials. The deciding factor between the two is definitely not appearances. When an FCP is either naturally in black or spayed with black, brown and green against a background of trees or woods, our experience is that it becomes invisible from the street, even when you know it's there and where it is, actually up to HOA stealth levels. But significantly more critical than that, if you really understood the camouflage FCP's "Christine-approved" seal of approval both in nature and depth of criticism, you would not propose appearance as a deciding factor for two 1/16 radials. You'd be back to performance issues. :>) Just in general, if two loaded 1/16 wave radials were as good as the experience we have had with the FCP, two loaded sixteenth waves would have already been out there in number, tons of folks happy as a pig in slop using it, it would be in ON4UN's book and we would not be having this discussion. Even with the single inductor for both radials, a pair of 1/16 radials requires something like a whopping 55 microhenries to tune it, and with a lossless coil has a 1.5:1 SWR bandwidth of only 26 kHz. The coil required is almost all of a $70 ten inch B&W #3026 Miniductor if you want to run QRO. Myself, the last time I tried to do something that extreme I melted the plastic rods with overheating. The smallest successful radial set I have seen is ON4UN's proffer of 4 loaded 1/8 wave elevated radials, which is in use with good results at one active contest station in my local area. John's radial length and count choice, to my analysis anyway, seems a carefully chosen balance between the loading inductor's size and losses, and narrowing of bandwidth, and the loss multiplier of length over ground. But that requires the 90 foot square for the radials, vs. the 66 foot line for the FCP. The FCP is not a shortened counterpoise like a pair of 1/16 radials. The FCP is a LENGTHENED counterpoise, LONGER than than a quarter wave in order to pull off a field cancellation trick by folding it. It also has a useful side effect of moving a typical tuned resonant Z of smallish vertical radiator plus counterpoise above 50 ohms. The junction of the FCP and vertical radiator is driven with a 1:1 isolation transformer (required) between it and coax center conductor, coax shield, and any connection to ground. A wind, rain and snow static ground is provided by a 10 watt 5 meg resistor bridging the windings which is the only connection between the two windings. The length of the radiating wire is adjusted at the far end to present zero reactance on the shack side of the isolation transformer. This way the residual inductance of the isolation transformer and the capacitive reactance of the FCP is soaked up in the pruning and tuning. Back to the current distribution... Remember that the current entering the FCP is set by the radiating wire because the apparent series resistance in the FCP is so low relative to the radiation resistance of the vertical radiator. The FCP's beginning current would be the same amplitude as the beginning current on the two radials. Set our imaginary power drive to get one ampere at the base of the antenna in both cases. Counting FCP segments 1 through 5. 33 feet per segment. Directions used are for illustration only. 1: center to 33 feet east 2: 33 feet east back to center 3: center to 33 feet west 4: 33 feet west back to center 5: center to 33 feet east and end insulator. Segments 2 through 5 carry the typical cosine current curve of a 0 to 90 degrees quarter wavelength. This is enforced working backward from the end insulator. Segment 1 has the cosine of -22.5 degrees to 0 degrees. The current max is at the connection between segments 1 and 2. Distributed current on segment 2 is the mirror image of distributed current on segment 1. Segment two is reverse current direction from segment one, therefore segments one and two completely cancel fields. Distributed current on segment 3 minus distributed current on segment 4 (distributed effective current on the west side) is almost identical to a mirror of distributed current on segment 5 which all that is left uncancelled on the east side. This means that the UN-cancelled distributed currents in the FCP are pair of ramps either side of center corresponding to the cosine of 67.5 degrees through 90 degrees, PROPORTIONAL to the ramp currents on two opposed elevated 1/16 wave radials, EXCEPT that on the two loaded radials the ramp current begins at 1.0 relative, and on the FCP begins at 0.38 relative at the center of the FCP. Since the cancel at ground due to opposite currents near center is the same in either system, and the ground loss is the integration of the square of the field intensity at ground times the ground area, the loss of the FCP is 0.145 rel
Re: Topband: Another non-traditional antenna working.
not forgetting my 2010 CQWW 160 award (counter poise + 120 up 130 over) mike w7dra On Wed, 16 Nov 2011 17:51:36 -0500 Guy Olinger K2AV writes: > This antenna started out as a "U", but in trimming it back to > resonance (folded counterpoise plus isolation transformer plus > antenna > length), the down part of the "U"s up, over and down got nearly > eliminated. There are four other stations using these who do not > wish > to be identified, who have used the counterpoise for significant > improvements, but to my knowledge have not put up the antenna with > all > the recent "refinements for cause". > > On Wed, Nov 16, 2011 at 8:40 AM, W0UCE wrote: > > Top Banders: > > > > Further to Guy's report, N3ND's Inverted U Antenna is the third > operational > > Top Band Antenna employing K2AV's Folded Counterpoise(FCP)versus > raised or > > buried radials. The other two are Inverted Ls with FCPs at K2AV > and W0UCE. > > > > After downsizing to a small QTH with limited space for a Top Band > antenna I > > expected my Top Band days were over. Not the case... My inverted > L vertical > > section is only 46.5' but results have been good to include > working JA, ZL > > and VK. The same antenna is used on 80 meters with ten 25' buried > copper > > radials and a matching network designed by Guy. Switching bands > is > > accomplished using a vacuum relay at the feed point. > > > > Jack W0UCE > > > > > > > >> We are testing N3ND's new 160 antenna tonight (Monday local time) > 1818 > >> @ 0005Z. This is another antenna based on RBN validated > untraditional > >> design. 73, Guy. > > > > To see the RBN, go to http://reversebeacon.net/srch.php > > > > Type in N3ND, hit enter. Look for the 160m spots around 03z 15 > Nov. The 03z > > spots are at 400 watts. The 00z spots were at 100 watts, before > the band > > was really open to the SE. RBN's from two other stations in the > area were > > down by similar measure at 00z and up at 03z. > > > > This is an up 70, over 60, down 5 wire fed via a feedline > isolation > > transformer against a 5/16 wave single wire folded counterpoise at > 8 feet. > > No radials. > > > > There is no way his small lot property could support a dense > radial field, > > either buried or elevated. Therefore, presuming that undense > irregular > > radials that would fit would be excessively lossy, per RBN data > previously > > gathered, the +33, -33 foot linear folded counterpoise > > (FCP) is used instead, elevated at 8 feet. The folds in the > counterpoise > > are designed to self-cancel fields as much as possible, thereby > minimizing > > ground induction, which is loss to skywave. The 66 foot straight > line (more > > or less, not critical) FCP footprint is much easier to place on > property > > than some miscellaneous attempt at a broadcast standard radial > field. > > > > 73, Guy. > > ___ > > UR RST IS ... ... ..9 QSB QSB - hw? BK > > > > > ___ > UR RST IS ... ... ..9 QSB QSB - hw? BK > 53 Year Old Mom Looks 33 The Stunning Results of Her Wrinkle Trick Has Botox Doctors Worried http://thirdpartyoffers.juno.com/TGL3141/4ec472c21fffd128dfbst02vuc ___ UR RST IS ... ... ..9 QSB QSB - hw? BK
Re: Topband: Location of beverage close to 60 ft hill
Not to worry. Your Beverage will work fine, as long as you feed it, etc. properly. They are not critical. It has well and often been said that Beverages just "want to work". My NE-SW 580' Beverage crosses a ravine wider than yours, not to mention running up and down a hill. Believe me, it hears very well indeed. Over the years, I have read a number of experiences of hams with Beverage antennas running up and down steep hills (some VERY steep) and crossing ravines, and absolutely NO ONE reported anything but good results. :-) When you cross a narrow stream or ravine like yours, there is no need to exactly follow the contour of the land. 73, Mike http://www.w0btu.com/Beverage_antennas.html On Wed, Nov 16, 2011 at 5:59 PM, wrote: > a. cross a 8 ft wide stream > > b. run about 10-15 ft up a bank behind my house > ___ UR RST IS ... ... ..9 QSB QSB - hw? BK
Topband: Location of beverage close to 60 ft hill
OK, After surveying my property and getting permission from the neighbor to use his property I have decided that in order to get a beverage pointed to about 35 - 45 deg. (from MD) and keep the beverage feed about 300 ft from my inverted L feed point I will have to: a. cross a 8 ft wide stream b. run about 10-15 ft up a bank behind my house Let me put this in perspective. Behind my house there is a dropoff about 60 ft down to a stream bed. My antenna will cross this and run partially up the bank. The feed point for the beverage is the part that is about 10-15 ft up the bank meaning that the antenna is pointing in the direction of the bank to get to the desired location (europe-africa). So here is my question. How much will the bank immediately above the feet point. Should I opt for another direction instead? Comments Please thanks Jim WA3MEJ ___ UR RST IS ... ... ..9 QSB QSB - hw? BK
Re: Topband: Another non-traditional antenna working.
This antenna started out as a "U", but in trimming it back to resonance (folded counterpoise plus isolation transformer plus antenna length), the down part of the "U"s up, over and down got nearly eliminated. There are four other stations using these who do not wish to be identified, who have used the counterpoise for significant improvements, but to my knowledge have not put up the antenna with all the recent "refinements for cause". On Wed, Nov 16, 2011 at 8:40 AM, W0UCE wrote: > Top Banders: > > Further to Guy's report, N3ND's Inverted U Antenna is the third operational > Top Band Antenna employing K2AV's Folded Counterpoise(FCP)versus raised or > buried radials. The other two are Inverted Ls with FCPs at K2AV and W0UCE. > > After downsizing to a small QTH with limited space for a Top Band antenna I > expected my Top Band days were over. Not the case... My inverted L vertical > section is only 46.5' but results have been good to include working JA, ZL > and VK. The same antenna is used on 80 meters with ten 25' buried copper > radials and a matching network designed by Guy. Switching bands is > accomplished using a vacuum relay at the feed point. > > Jack W0UCE > > > >> We are testing N3ND's new 160 antenna tonight (Monday local time) 1818 >> @ 0005Z. This is another antenna based on RBN validated untraditional >> design. 73, Guy. > > To see the RBN, go to http://reversebeacon.net/srch.php > > Type in N3ND, hit enter. Look for the 160m spots around 03z 15 Nov. The 03z > spots are at 400 watts. The 00z spots were at 100 watts, before the band > was really open to the SE. RBN's from two other stations in the area were > down by similar measure at 00z and up at 03z. > > This is an up 70, over 60, down 5 wire fed via a feedline isolation > transformer against a 5/16 wave single wire folded counterpoise at 8 feet. > No radials. > > There is no way his small lot property could support a dense radial field, > either buried or elevated. Therefore, presuming that undense irregular > radials that would fit would be excessively lossy, per RBN data previously > gathered, the +33, -33 foot linear folded counterpoise > (FCP) is used instead, elevated at 8 feet. The folds in the counterpoise > are designed to self-cancel fields as much as possible, thereby minimizing > ground induction, which is loss to skywave. The 66 foot straight line (more > or less, not critical) FCP footprint is much easier to place on property > than some miscellaneous attempt at a broadcast standard radial field. > > 73, Guy. > ___ > UR RST IS ... ... ..9 QSB QSB - hw? BK > > ___ UR RST IS ... ... ..9 QSB QSB - hw? BK
Re: Topband: Another non-traditional antenna working.
For short radials make them equal lengths and load using a single coil. Dave WX7G On Nov 16, 2011 10:49 AM, "Richard (Rick) Karlquist" wrote: > On 11/15/2011 9:10 PM, Guy Olinger K2AV wrote: > > > field, either buried or elevated. Therefore, presuming that undense > > irregular radials that would fit would be excessively lossy, per RBN > > data previously gathered, the +33, -33 foot linear folded counterpoise > > (FCP) is used instead, elevated at 8 feet. The folds in the > > counterpoise are designed to self-cancel fields as much as possible, > > thereby minimizing ground induction, which is loss to skywave. The 66 > > > 73, Guy.e > > It seems to me that the folded counterpoise is equivalent to > a couple of loaded short radials, except that "linear loading" > is used instead of lumping loading coils. > Thus the ground induction loss is not reduced by the folding. So this > is just a non-traditional implementation of 2 short loaded elevated > radials. Nothing wrong with that, if implemented carefully. The > decrease in gain is probably within the margin of error of RBN. > > In the described small backyard situation, I would think that making > radials out of plain wire and loading them with coils at the feedpoint > would be more acceptable from the visual clutter viewpoint. > > Rick N6RK > ___ > UR RST IS ... ... ..9 QSB QSB - hw? BK > ___ UR RST IS ... ... ..9 QSB QSB - hw? BK
Re: Topband: Another non-traditional antenna working.
On 11/16/2011 12:10 AM, Guy Olinger K2AV wrote: >> We are testing N3ND's new 160 antenna tonight (Monday local time) 1818 @ >> 0005Z. This is another antenna based on RBN validated untraditional design. >> 73, Guy. > This is an up 70, over 60, down 5 wire fed via a feedline isolation > transformer against a 5/16 wave single wire folded counterpoise at 8 > feet. No radials. > > There is no way his small lot property could support a dense radial > field, either buried or elevated. Therefore, presuming that undense > irregular radials that would fit would be excessively lossy, per RBN > data previously gathered, the +33, -33 foot linear folded counterpoise > (FCP) is used instead, elevated at 8 feet. The folds in the > counterpoise are designed to self-cancel fields as much as possible, > thereby minimizing ground induction, which is loss to skywave Is there more info available on this antenna? Especially a diagram (or crude drawing) of how things are done would be appreciated. A NEC model would be fantastic, but I'd be more than happy to prepare that from the crudest drawing anyone could send me, and then make it available to everybody else :) -- All rights reversed. ___ UR RST IS ... ... ..9 QSB QSB - hw? BK
Topband: 9n7md to start 160 tonight
They erected the 160 mtr today. Around 00:00 UTC they will begin with IZ2ESV at key. Since this is their first night please send me any reports on areas that hear them and didn't work them so they can adjust operating habits tomorrow. 73 Don N1DG 9n7md pilot - N1DG--Licensed since 1962 EX-WB2DND, A61AD (GUEST OP, QSL MGR), /VP8O, /KH4, A52DG, /KH9, /BV, /VS6, /4X, /9V /A7 Webmaster: VP8O, K4M, BS7H, 3Y0X, K5K, A52A, VK0IR, 9M0C, ZK1XXP, WB2DND/KH9, BQ9P, ZL9CI 2006 inductee into the CQ Magazine DX Hall of Fame Member: CWops, ARRL, DDXA, YCCC AIM SKYPE: aurumtel Please consider the environment before printing this email ___ UR RST IS ... ... ..9 QSB QSB - hw? BK
Re: Topband: Another non-traditional antenna working.
On 11/15/2011 9:10 PM, Guy Olinger K2AV wrote: > field, either buried or elevated. Therefore, presuming that undense > irregular radials that would fit would be excessively lossy, per RBN > data previously gathered, the +33, -33 foot linear folded counterpoise > (FCP) is used instead, elevated at 8 feet. The folds in the > counterpoise are designed to self-cancel fields as much as possible, > thereby minimizing ground induction, which is loss to skywave. The 66 > 73, Guy.e It seems to me that the folded counterpoise is equivalent to a couple of loaded short radials, except that "linear loading" is used instead of lumping loading coils. Thus the ground induction loss is not reduced by the folding. So this is just a non-traditional implementation of 2 short loaded elevated radials. Nothing wrong with that, if implemented carefully. The decrease in gain is probably within the margin of error of RBN. In the described small backyard situation, I would think that making radials out of plain wire and loading them with coils at the feedpoint would be more acceptable from the visual clutter viewpoint. Rick N6RK ___ UR RST IS ... ... ..9 QSB QSB - hw? BK
Re: Topband: Another non-traditional antenna working.
Top Banders: Further to Guy's report, N3ND's Inverted U Antenna is the third operational Top Band Antenna employing K2AV's Folded Counterpoise(FCP)versus raised or buried radials. The other two are Inverted Ls with FCPs at K2AV and W0UCE. After downsizing to a small QTH with limited space for a Top Band antenna I expected my Top Band days were over. Not the case... My inverted L vertical section is only 46.5' but results have been good to include working JA, ZL and VK. The same antenna is used on 80 meters with ten 25' buried copper radials and a matching network designed by Guy. Switching bands is accomplished using a vacuum relay at the feed point. Jack W0UCE > We are testing N3ND's new 160 antenna tonight (Monday local time) 1818 > @ 0005Z. This is another antenna based on RBN validated untraditional > design. 73, Guy. To see the RBN, go to http://reversebeacon.net/srch.php Type in N3ND, hit enter. Look for the 160m spots around 03z 15 Nov. The 03z spots are at 400 watts. The 00z spots were at 100 watts, before the band was really open to the SE. RBN's from two other stations in the area were down by similar measure at 00z and up at 03z. This is an up 70, over 60, down 5 wire fed via a feedline isolation transformer against a 5/16 wave single wire folded counterpoise at 8 feet. No radials. There is no way his small lot property could support a dense radial field, either buried or elevated. Therefore, presuming that undense irregular radials that would fit would be excessively lossy, per RBN data previously gathered, the +33, -33 foot linear folded counterpoise (FCP) is used instead, elevated at 8 feet. The folds in the counterpoise are designed to self-cancel fields as much as possible, thereby minimizing ground induction, which is loss to skywave. The 66 foot straight line (more or less, not critical) FCP footprint is much easier to place on property than some miscellaneous attempt at a broadcast standard radial field. 73, Guy. ___ UR RST IS ... ... ..9 QSB QSB - hw? BK ___ UR RST IS ... ... ..9 QSB QSB - hw? BK
Re: Topband: contesting in a field
With the caveat that I am not any kind of SME on 160 meter antennas, I would be surprised that you'd need much of a counterpoise for an End Fed Half Wave antenna. My experiences with an End Fed Half Wave antenna show that a small (small as in length of a singular wire) counterpoise is all that's required. Assuming the physics for an 80 meter or 40 meter EFHW antenna carries over to 160 meters I don't see the need for anything of length or numbers - for my 80 and 40 meter EFHW antennas I use about 3 feet of counterpoiseI've lengthened that wire up to a 1/4 wave and have noticed zero improvement in SWR or received signal strength at several RBNs. 72, Jim Rodenkirch, K9JWV > From: k...@radioprism.com > To: topband@contesting.com > Date: Tue, 15 Nov 2011 22:15:04 -0700 > Subject: Re: Topband: contesting in a field > > I like resonant, voltage-fed verticals for their simplicity. For field > ops, > they can be a very quick way to deploy a working antenna. On 40 meters, > for example, you're only dealing with 70ft- or 35ft if bent like an > "L", > Half Square, Bobtail, etc. > > If you could catch Murphy on vacation, and if you can raise a large > enough balloon to support ~268ft of smaller gage wire, you can go with > a voltage fed half wave using an LC tank to tune it. Tap up the coil > from the ground end with your coax for a 1:1 SWR (assuming your LC is > properly resonated) Your farm isn't near any airports, is it? OTOH if > it's windy, this could be a rather frustrating event. (technically, > you're 'pushing it' a little with anything over ~200ft in height) > > You don't need much of a counterpoise, feeding this way- roll out > however much chicken wire or wire cloth as you care to- or think > 'radials', if that is your preference. A denser, shorter radial field > or counterpoise ought to work pretty well. > > Having the current max up 134ft couldn't hurt. It ought to play > reasonably well. As always, more ground is better ground. I like > the roll(s) of chicken wire approach. > > 73, David K3KY > > > >The last thing I need is a reason to generate flammable gasses in bulk :) > > > >We homeschool, so maybe that would fit the stereotype everyone expects. > >"And then they did a chemistry experiment and blew up their garage." > > > >I've thought about an inverted L at home, I have just short of an acre, I > >think the above ground part wouldn't be a problem its the radials. I'm > >assuming in the wide open spaces at the farm I can pursue the same elevated > >radials I would for a kite/balloon vertical? The elevated vertical thing > >seems to be the best bang for the effort, and in some ways less effort > >especially for temporary ops like this. > > Chris > > ___ > UR RST IS ... ... ..9 QSB QSB - hw? BK ___ UR RST IS ... ... ..9 QSB QSB - hw? BK
