++++++++++++++++++++++++++++++++++++++++++++++++ Date: Sat, 3 Mar 2001 23:42:34 -0500 From: Victor R Dively Subject: [Elecraft] Non-resonant dipoles; multi-band dipoles Craig, K4IA asked whether or not a non-resonant dipole might be better for multi-band use. Another thing to consider is an off-center fed dipole. The ARRL "More Wire Antenna Classics, Volume 2" discussed off center fed dipoles in some detail. An intriguing design is the 68 feet long dipole where the feedpoint is 41 percent from one end. You end up with a 40M dipole that is also resonant on 20, 15, and 10M. You also end up with a very reasonable SWR across a wide spectrum of frequencies, so you can easily tune to 12. 17 and 30M also. If you used a regular center fed 40M dipole, you would see high SWR, except on 40 and 15M, trying to do the same thing. It seems like the only thing really going for a center fed dipole is that, at 1/2 wavelength heights, the impedance at the resonant frequency is a close match for coax. However, If you aren't using coax, I'm not sure if there is any good reason to prefer the center fed dipole over a off-center fed. Try the 41% off center fed dipole with 450 ohm ladder line if you are interested in multi-band use, and keeping the SWR much easier to match. Vic KG4HTT Date: Sun, 4 Mar 2001 10:18:30 -0800 From: "Ron D'Eau Claire" Subject: RE: [Elecraft] Non-resonant dipoles; multi-band dipoles Vic, KG4HTT wrote: "...It seems like the only thing really going for a center fed dipole is that, at 1/2 wavelength heights, the impedance at the resonant frequency is a close match for coax. However, If you aren't using coax, I'm not sure if there is any good reason to prefer the center fed dipole over a off-center fed..." The biggest advantage to center feeding a doublet with open wire line is to minimize the radiation from the transmission line (and the pickup of noise and other QRN from the transmission line in receive). Open wire line suppresses radiation (and pickup) by having the currents in each side equal and opposite. That is, they are balanced and the field around each wire cancels out the field around the other wire. The only off-center fed antenna where that is true to a significant degree is the classic Zepp where the open wire feeders feed a 1/2 wave radiator at one end. In that case one feeder goes to a very high impedance point at the end of the radiator because it is exactly 1/2 wavelength long, and the other feeder goes to an insulator. So they both look into very high impedances. Still, that isn't as well balanced as the center fed, and it is a single-frequency affair. As soon as the radiator is no longer 1/2 wavelength long, the feeders start radiating. In any multi-band off-center fed system that I've seen the feeders may do most of the radiating on some bands. Is that bad? Not always, but it can be if the feedline has to run through places where you wouldn't expect an antenna to radiate very well. It's safe to assume that the feeders are radiating as much as any other part of the antenna in those cases. Ron AC7AC K2 # 1289 ++++++++++++++++++++++++++++++++++++++++++++++++ Date: Sun, 25 Feb 2001 17:37:25 -0700 From: "Santa Fe" Subject: [Elecraft] antenna at W5YA / portable today Responding to request for antenna info: The antenna is one of my own design, which does not mean that someone else hasn't done it. It is shaped like the letter U on its side so I call it a lazy U. It may well exist somewhere else in the literature, I just don't know about it. Apologies to any other original originator. You can think of it as a bent 20 meter windom which is fed off center to get a high impedance point. Or you might think of it as a top loaded vertical with a counter poise. Regardless of how you think of it, it works. The two horizontal elements cancel each other out so the radiation is almost entirely from the vertical element. The top horizontal element was seven feet long, the bottom one 9 feet long, and the vertical element was 17 feet tall and the base of it was 15 feet up. All minor variations seemed to work on the computer, but this gave the best compromise between ten meters (no vertical radiation) and slightly more manageable impedance on 15 meters where it is very high. The antenna was made of # 22 wire, and the horizontal elements were supported by fishing line with tiny spinner clips and swivels, no insulators, and pulled out at a 45 degree angle, tied to tent stakes. These two elements want to be more or less parallel but seem to act essentially the same at 45 degree angle as they do at a 90 degree angle to the vertical, based upon computer modeling. I fed it at the juncture of the vertical and the bottom element through a homebrew 4:1 balun in a film can (TNX W1CG). This antenna models to have very low angle radiation on ALL bands 10-20, and high impedances meaning it will be efficient even with a lousy ground which we have here in the desert. It also means the feedline is tuned and has high SWR on it. It wants to be short, mine was 20 feet at most, and a good tuner is required. The KAT-2 is a GOOD tuner. Make no mistake. Most of the tuners on the market are dummy loads IMHO. The KAT-2 made easy work of the tuning, and the antenna worked DX on each and every one of the bands. Best DX, D68C on ten meters, did take a few minutes to get our QRP turn in the pile-up. Also a handful of European contacts, no problem. It is a DX antenna, BUT, now this is cool, you want higher angle stateside radiation from same antenna? You shape it like a Z instead of lazy U, and you have higher angle radiation for stateside contacts, not straight up either. Neat, huh? Total weight INCLUDING 33 foot pole, three pounds. Pole needed here. Last time I shinnied up a cactus I ruined a perfectly good pair of jeans. Course our tent, now that weighed about 6,000 pounds, but we rolled that ;-) ++++++++++++++++++++++++++++++++++++++++++++++++++++ Date: Mon, 26 Feb 2001 19:24:12 -0500 From: "John L. \"Jake\" Carter" Subject: RE: [Elecraft] Portable antenna Chas -- W1CG: I've tried both square and delta loops. The deltas are much easier to put up and I don't see much difference in performance between the two. I get great signal reports with a full wave 10m wire delta loop with the apex at about 30' and the feed point at one of the bottom corners. The feed is not in the horizontal side -- its in one of the diagonal sides. I feed the loop with a quarter-wave matching section of 75 ohm coax -- works great -- I get very close to a 1:1 SWR without a tuner. To raise the antenna I just toss a line over a tree limb, tie it to the apex of the delta loop, hoist the loop up, stretch out and secure the corners and get on the air -- very easy. Hope this helps. 73, Jake -- N4UY (K1 #384) +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Date: Mon, 26 Feb 2001 16:13:01 -0600 From: "Stuart Rohre" Subject: Re: [Elecraft] Portable antenna Charles, Last year at Field Day, I found out the merits of square horizontal loop vs. Delta Loop horizontal. One less pole to find! Really, if you make them symmetric there is not discernable difference. We had light poles situated around a football practice field such that we could do two corners of a delta squeezed to be longer east and west. Then, we put up a home made PVC slip up mast, (3 ea 10 foot sections to make a big overlap to get up 20 feet), and used a couple of back stay guys in a Vee, to counter the pull of loop wires on the legs tied to that corner. Worked great, and modeling confirmed that all we did was squish the pattern out to favor east and west. A lot of fill in happened on higher bands, and it worked great to North and South as well. Feed either type in a corner. Use straight lengths of wire for each leg and simply join wires with wire nuts at corners, (Thanks Ron!) Easier than wrestling one big roll of wire around a loop, especially in trees. We had each leg on a spool. Went up in 20 minutes or less, using one ladder and a crew of about 3 folks. The 20 foot ht. was dictated in how high up the ladder would safely reach with average height person on it. Don't make the error we did one year, used the tallest person in the club to climb the ladder and hang the antenna on Sat., and then when he was not there at takedown on Sun. it was really a chore, as no one else could reach that high safely! Our loop was about 1.25 waves on 160m, but its use was planned for 80m and up to 10m. And it did work well with transmatch on all bands. We did not try 160, and 80m at night did not have enough contacts working FD to make it worth firing up on that band. Besides, they all had trouble hearing each other, complaining of summer static, while our loop attenuated lightning static. The great thing about a low loop, is it is ideal for North American contacts which is the main point of field day. On 40m SSB, the loop attenuates the HF low angle skip from European BC stations that required audio DSP to cancel their heterodyne interference in past years. The BC was there, but 10 dB or more down from the stateside FD contestants. It really played well on 20m and 15 m as well as 10m. On 15m, the low loop worked into HI twice in early part of Sat. afternoon, nailing down one of the remote sections you want in FD. Thus its DX potential was proved. I had not had much experience with loops until that field day, although I knew several club members who swear by them as good all around antennas. I have a buddy near me who has one for 40m as his only antenna and uses it on all higher bands. This is easy to do with ladder line, which is low loss. Good twin lead would also work as well. GL, Stuart K5KVH ++++++++++++++++++++++++++++++++++++++++++++++++++++++ Date: Mon, 5 Mar 2001 17:07:52 -0600 From: "Stuart Rohre" Subject: Re: [Elecraft] Non-resonant dipoles; multi-band dipoles Three problems with all off center fed dipoles, the SWR is not as good over all bands, The pattern will be distorted by the off center feed, and most of all, The feedline will radiate, since unequal currents will be flowing in it, from coupling more to the radiated field on one side than the other. A center fed antenna has the advantage of balance when its feed is equidistant from both ends of the antenna. (Least chance of feedline radiation). See a rather good work up on the OCF in the Bill Orr, W6SAI Antenna Handbook, (CQ Publications). You need a balun and a transmatch for all band coverage just as you do with a center fed dipole used on other bands. SWR to a modern commercial rig is an issue that cannot be ignored, thus making it an issue when multibanding any antenna. In the urban environment, the OCF can add to problems of RF getting into not only your own shack but also into other RF sensitive devices in the home. As a matter of fact, any dipole used on other than its cut frequency becomes a non resonant dipole, and would require a transmatch. Even the touted ability of a 40m dipole to operate on 15m is not exactly true, you will have lowest SWR not on the exact harmonic of the frequency to which the antenna was cut for 40m, but probably out of the 15m band. A transmatch takes care of that. In any practical case, the loss is unnoticed from having the transmatch circuit. Stuart K5KVH ++++++++++++++++++++++++++++++++++++++++++++++++++++ Date: Sat, 17 Mar 2001 17:20:53 -0600 From: "Larry" Subject: [Elecraft] Attic Antenna Just a note about attic antennas. I have used one off and on for years with good results operating at QRP levels. I use the tuner in my K2 and a 4:1 balun at the rig. For feedline I use parallel RG62(100 ohm) coax to make a sheilded 200 ohm parallel feedline. This way I can run the feedline through the house and not worry about it getting close to metal objects. My antenna is 50' long and tunes 40 thru 10 meters with ease. And it works pretty good at a height of about 17'. Larry N0SA ++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Date: Wed, 21 Mar 2001 09:05:19 -0500 From: Charles Greene Subject: Re: [Elecraft] Random wire antenna At 06:28 AM 3/21/2001 -0600, tom quinn wrote: >My K2 #1804 is coming right along, and it's time to get an antenna >ready. About the only antenna I can use is a long wire about 30 feet >long out my apt window, strung ovet to the balcony. I have an Emcraft >ZM-2 ant tuner. Do I have this right--the antenna should be >non-resonant, but the counterpoise wire should be 1/4 wave for the >intended band? That pretty well restricts me to 20M and above. > >I would like to hear any ideas on this > >Tom, You should avoid 1/2 wave length antennas unless your tuner will tune them. There's a current node at the end of a 1/2 wave length antenna which gives a high voltage at that point, however a lot use the 1/2 antenna as an end fed zepp either fed with a 1/4 feed line or with a series tuned LC circuit at the current node. More common is a 1/4 antenna and a 1/4 counterpoise. You could try a TV rotor cable with 1/4 wave dipoles cut for several bands for both the antenna and the counterpoise. 73, Chas, W1CG ++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Date: Wed, 21 Mar 2001 16:19:31 -0600 From: "Stuart Rohre" Subject: Re: [Elecraft] Random wire antenna As long as you have a transmatch, the counterpoise can be less than quarter wave and still work, or you could zig zag one for lower bands. It does NOT have to be straight. The Random wire, though will work poorly in that it can be one directional, and mostly off its end, if long enough for a given band to be a "long wire". I would suggest a center fed dipole, even if the ends are dropped at right angles to middle section, or zee folded to fit your space, and tuned for all bands. Will give you better omni pattern and more contacts than a random wire. Had a random wire as a Novice and could not work out of town! 73, Stuart k5KVH +++++++++++++++++++++++++++++++++++++++++++++++++++++++ Date: Wed, 21 Mar 2001 16:23:25 -0600 From: "Stuart Rohre" Subject: Re: [Elecraft] Random wire antenna Charles of course, made a good point in the case of END feeding a half wave wire. the best beginning antenna, which will only require a transmatch for bands out of resonance is the center fed dipole. At a low height, or on higher bands than its half wave cut, it can give near omnidirectional patterns, and lobing will tend to fill in in reality, although at 10m, it might show a number of lobes, you will still hear and work all directions. 72, Stuart k5KVH ++++++++++++++++++++++++++++++++++++++++++++++++ Date: Wed, 21 Mar 2001 21:57:15 -0500 From: "Francis Belliveau" Subject: Re: [Elecraft] Random wire antenna Stuart, All ideas expressed on the list were good ones. Many HAMs like yourself overlook possibilities when thinking about HF antennas. As expressed by others, "do not think in straight lines". For instance is your appartment had 3 windows on the same wall you could run sideways horizontal from the center one to each of the other two then out away from the wall. Then you could even let some wire hang vertical from the ends. That would yield a "bow tie" pattern radiating perpendicular from the wall. Bottom line is get as much wire as you can as high as you can. Good Luck, Fran +++++++++++++++++++++++++++++++++++++++++++++++++++ Date: Thu, 29 Mar 2001 14:57:49 -0600 From: "Stuart Rohre" Subject: Re: [Elecraft] Am I getting out???? Tom and the group, I started out in ham radio with a similar antenna and could not get out of the city limits. That lead to a life long fascination with antennas and I can offer some hints. Depending on how you have run your counterpoises, you may be experiencing shadowing by the building on your outside wire, and the inside wires are coupling into the building frame, a lot of precious RF. A single wire can be very directional off the end and that is the usual cause of complaints like Tom's. I heartily believe we all need more than one antenna for many occasions, but that it is hard to beat a simple dipole, fully balanced antenna, for it will not need a transmatch with its losses on the resonant band. If you parallel 3 wires and fan them out you can make a 20,15,10 meter dipole leg on each side of center feed point. In the apartment upper floor case, a very effective balcony antenna can be made from conduit for the fundamental band, stuck out at right angles to the building. Use PVC pipe to insulate it from the clamp to the balcony rail. Use PVC to insulate the center. Run coax up the hollow conduit to the center. Now, for 2 other bands, use wire on TV standoff pipe clamp insulators, and then angle the wire to the center and feed in parallel with the conduit. If the conduit is large, you can get by with less than 32 feet total length for the 20m dipole part. Make the 15 m and 10 m dipoles of wire at full size, based on 468 over f in MHz as a starting point. If the antennas measure long with an antenna analyzer, fold back the wire on ends. You could try to make the 20m out of two 10 foot conduit lengths, and use a coil of large copper solid ground wire from Home Depot electric dept. as a matching coil at center, to make up the capacitive reactance of the short dipole. Dipoles of 60 per cent of full size still have efficiencies in the 90 per cent range and are good antennas. At right angles to the building, you will have lobes to the two directions, as well as straight up. The straight up lobe can be used to work short skip, around your state or nearby states. The other directions should give you desired DX skip. You will not need any inside counterpoise wires for the dipoles. An antenna can be too high. It will still hear well, but its transmitting power may have too much in high angle lobes. 20 stories would be like 200 feet plus off the ground. At 20M, that is pretty high. Years ago, we used horizontal 10 wave Vee beams at Field Day at low elevation. Someone thought we should put them up on our 40 foot tower at another Field Day. They did not work within our desired North American FD target area, but skipped over it. Thus, they had been put higher and higher until they were too high for the job we desired. An inverted, Double Extended Zepp dipole with 5/8 wave legs did much better that year! And it still worked DX with gain, out across the Pacific to New Caledonia on Field Day night. Another thing you could try is to make a vertical dipole out of coax, with the shield being half of it. Put a ferrite choke with the coax placed coiled a couple of turns thru it to define the "end " of that side of the dipole, 1/4 wave from where you have stripped off the braid, and soldered the center conductor to a wire of quarter wave that will hang with a fishing weight on its end as the other half of the dipole. Now this is mainly a one band solution, such as for 20m, and you hang it as far off the balcony as you can on the end of a PVC or other insulated pipe. Run the coax out to the end of the pole, and then let the coax hang from the point that has the core choke. Again, this is going to suffer from the building shadow in that direction, but it will have the same horizons as the conduit dipole. It just will be closer to the building, if that is a problem. Of course, you could always make the conduit dipole with two sections held by hose clamps to bring it in when you are not operating. The coax dipole could be loaded on higher bands, and the coax loss would not be much if the station i s on or near the balcony. I greatly discourage a random wire such as you have in urban environments. I never see them work as well as even a dipole in an attic. Some use them as field antennas and they work well if you are high on a hill camping in the clear. Another balcony antenna is the quarter wave sloper with its base clamped and insulated from the balcony rail, made again of conduit, but this too requires several counterpoises, and that may not be effective in your building. A half wave antenna has twice the capture area of the base fed vertical or sloper, and is to be preferred for that. 72, Stuart K5KVH ++++++++++++++++++++++++++++++++++++++++++++++++++++++ Date: Fri, 30 Mar 2001 11:37:55 +0200 From: "Deinhardt, Toby" Subject: RE: [Elecraft] Am I getting out???? Hi Stuart & Tom, I am a newcomer to the shortwave bands, and can not put the kind of antennas we all dream about ... > I greatly discourage a random wire such as you have in urban > environments. I use a random wire in a very urban enviroment, and, at least for me, it seems to work well, so I would not generally say that this not the way to go. A lot probaly has to do with type of buildings surrounding the antenna, the height of the buildings, the height of the feed point, the hight of the far end, etc. etc. On 160 and 80 I am able to work all over Europe with 5 watts from DL. 40 is a no no right now, cause #885 talks in many tongues here, i.e. #885 has a problem which hasn't been solved yet [Gary: if you read this, I hope to do the ALC measurements this weekend]. On 30 and 20 I have worked a bit of european short skip. No DX or higher bands yet. This is with a 40m +/- a couple meters, very thin (0,5 mm radius) stealthy wire from my appartment (about 15 m over ground) to a small tree (about 4 m high). I have various bits of wire and a radiator as counterpoises. The antenna is fed directly by the K2-ATU without any feedline, transformers etc. This antenna appears to produce a fairly large number of high angle lobes, which means it might not be a DX machine works well within a radius of c. 2000 - 3000 kms. Two last remarks: Up to now all my QSOs on shortwave have been in CW, and secondly my CW is still fairly (very) slow. It is not always easy to find a partner willing to deal with a newcomer with a weak signal. Do not give up after just an hour of hunting, it may take a while, but the reward is worth it. vy 73 de toby - -- DJ7MGQ (ex dd5fz, dg5mgq) K2 #885 ++++++++++++++++++++++++++++++++++++++++++++++ Date: Fri, 30 Mar 2001 12:29:51 -0600 From: "Stuart Rohre" Subject: [Elecraft] A link to Antenna debugging information After several new rig owners lamented their problems with random wire antennas and others, I found this EXCELLENT tech paper on the Force 12 Antennas web site, http://force12inc.com. Debugging An Antenna System, by Tom Schiller N6BT. Tom is the President of Force 12, who have many innovative beam and compact antenna models. I have heard him recount the DX contest winning operation he did from Jamaica in past years. ("Verticals on the Beach") He definitely knows his antennas and the basics of all antennas, and covers troubleshooting them very well. This troubleshooting aid, will go a long way to zeroing in many causes of antennas failing "to play". His outline also emphasizes the thing one needs to do in troubleshooting any failing circuit or rig, etc. Change only ONE thing at a time, and keep NOTES on what you do each step! I write in the margins of my kit manuals, any thing about a test that may be slightly differing from the text. I write clarifying notes, if the directions are vague to my understanding. Keep SWR, Z, and gain figures for each new antenna in your log book, after putting them up for future reference if things seem to change for the worse. The blank backs of the ARRL log book pages are ideal for notes drawings and charts. 72, Stuart K5KVH ++++++++++++++++++++++++++++++++++++++++++++++++ Date: Fri, 30 Mar 2001 16:57:07 -0700 From: Larry East Subject: Re: [Elecraft] Am I getting out???? At 02:38 PM 3/30/01 -0600, Stuart Rohre wrote: >Toby, >I maybe did not make clear; my random wire did make local contacts, but DX >is what we all want, right? For DX, a single wire has a directionality that >greatly limits what you can do. On the bands 20m and up, we all can likely >put up some dipole, even if short, and thus benefit from a balanced antenna >independent of an earth connection except in the reflection. I have a end-fed 450 length of wire up 20 feet (more-or-less, depending on droop and the lay of the land) running up a small hill behind my house in an easterly direction. It is a darn good DX antenna on 20M and up (sometimes for 40 and 30 as well -- depending on direction). A wire that long has multiple lobes for the higher bands so one is not confined to working in one or two directions. Of course, it might be a little difficult to string up something that long in an "urban environment" unless your are really, really sneaky! :-) 73, Larry W1HUE/7 PS -- "How do you feed it" you ask? I have a 9:1 transformer at he base and feed it via RG-8X against ground (just a ground rod -- no counterpoise). I get a good match on all bands from 40 thru 15M, but the feed impedance bounces around quite a but on 12 and 10M. But the K2 auto-tuner handles it with no problems. It even works as a transmit antenna on 160 and 80 in spite of its low height. +++++++++++++++++++++++++++++++++++++++++++++++++++ Date: Sat, 31 Mar 2001 23:43:26 +0100 From: "David Johnson" Subject: [Elecraft] Stealth antenna Of the various cheap and simple antennas I've used over the years, a doublet seems to perform as well as any. It depends on circumstances, but they can be made very inconspicuous if needed. You will need an ATU of some sort as well as a 4:1 balun. My doublet seems to work very well on the K2, it's got a 100 foot top, elevation 30 feet, about 25 foot of open wire feeder, feeder and top section single length (for each side) of 32 strand black pvc insulated hookup wire, 4:1 balun in plastic box, hole through wall into upstairs shack, 3 feet of UR-76 coax to VCI ATU. Tunes 80 to 10 with no problems and gives plenty of DX contacts. Dave, G4AON K2 #1892 ++++++++++++++++++++++++++++++++++++++++++++++++++ Date: Sun, 1 Apr 2001 10:19:53 -0400 From: "Francis Belliveau" Subject: Re: [Elecraft] Stealth antenna Lamar et. al. An antenna that takes the shape something like ---- -| <--> radiation ---- Allows a full sized 20 meter antanna in a 10x10 room. Preferred radiation pattern is also indicated. Obviously 10 and 15 meters can also be supported from such a configuration. If you are lucky and have a convenient door nearby you might combine 2 rooms to get 40 or 80 metters worth of wire. To complete the picture above run your feedline up the center of a wall to the ceiling. Secure that location as your feedpoint and run an equal amount of wire out from there. How much wire you can put up depends upon room geometry. You can go out along the wall containint the feedpoint or straight toward the opposite corners. I ran a 15 meter resonant antenna from a first floor room for my HW-8 and it worked quite well. Measure out the space you have, add up the available places you can run wire and see what fits. From the second floor I expect that a dipole or doublet are your best indoor bets. I used transformer wire supported at the ends by common pins and it was virtually invisible. I used a poster to hide the feedline. Fran ++++++++++++++++++++++++++++++++++++++++++ Date: Sun, 1 Apr 2001 19:55:33 -0500 From: "David Bixler" Subject: RE: [Elecraft] Stealth antennas Hi Lamar: I've been watching this thread with interest. The suggestion I wanted to make is a source of "invisible wire" that I have used for years when stealth antenna were needed. I found that the ringer coils in old fashioned mechanical telephone ringers have hundreds of feet of small gauge wire on them. Not sure of the wire gauge, but it is probably 32 gauge or so. Really thin stuff and makes for very hard to see antennas. I used this wire successfully when I was living in boarding rooms at college and later many times at hotels for undercover operating. The old telephones are often found at yard sales and go for a quarter or fifty cents around here. Look for the phones that "ding" when you tap or shake them and have a mechanical ringer loudness adjustment on the bottom. 72 and good luck, Dave David Bixler W0CH - VK2IQX Seneca, MO Main Web Site: http://www.qsl.net/w0ch Mirror Site: http://showcase.netins.net/w0ch QRP: Little Radios, Big Fun! ++++++++++++++++++++++++++++++++++++++++++ Date: Wed, 4 Apr 2001 14:59:13 -0500 From: "Stuart Rohre" Subject: Re: [Elecraft] remote antennas The G5RV, and the McCoy dipole, which is a half wave cut for the lowest band of interest and fed from balanced parallel line, (450 ohm or 300) can both be erected as inverted Vees from one support, tall tree, pole, etc.. If you are outdoors and have a Lot of room, you can make the dipole legs longer, up to 5/8; and that gets you some 3 dB gain, and all band coverage. The multi lobing that appears with such a wire on high bands seems to fill in well enough to be an excellent 20,15, and 10 m Field antenna, if the fundamental 5/8 waves are cut for 80m. The legs are 175 feet for 80m CW, but half that would make a competitive antenna for 40m and up.Have used such to place 8th in QRP class in contest. 72, Stuart K5KVH +++++++++++++++++++++++++++++++++++++++ Date: Thu, 5 Apr 2001 10:08:09 +0200 From: "Dieter Klaschka" Subject: Re: [Elecraft] remote antennas - ----- Original Message ----- From: "Arthur Laurent" To: Cc: Sent: Wednesday, April 04, 2001 9:56 AM Subject: [Elecraft] remote antennas > Kevin Swesey says, > > <...Would like to hear from other subscribers as to what they use > in the field. Remember portability is my main objective... >-------------------------------- Hi, Kevin, When I am on holidays I use a fibre mast abt 9 m high and a little metal post from a cattle fence to attach the mast to with short rubber ropes. I use a wire vertical for 10 Mc and 14Mc with one radial (kinda vert dipole, Upper-and-Outer from the GQRP ant book); when you lift or drop it you can influence SWR. For 14 Mc I have a loop with a lambda 4th coax 75Ohm to adapt - then coax 50 Ohm to rig. For 7 Mc I use a FOXX with the C and the little coil in a film cannister. For 14 and 10 an inverted V should be a good solution - I used one for 7 Mc when having been on the coastal line of the UK, but this needs a rather wide space to be fixed. Since I mostly have B&B facilities it all depends on the actual situation. 73, Dieter.DL2BQD ++++++++++++++++++++++++++++++++++++ Date: Thu, 05 Apr 2001 10:51:54 -0400 From: "David A. Belsley" Subject: Re: [Elecraft] K2 all band antenna? Tony: I suspect, for a single wire, all-band antenna, it is hard to beat the extended double zepp (2XZepp). This is a center-fed dipole 5/8-wave instead of 1/2-wave long. You have got to feed it with open-wire line (because the swr can get very high for some bands) and use a transmatch at the point you switch from open wire to coax. If you can't place the transmatch near the transceiver, you can simply switch an antenna analyzer, such as the MFJ 259B, into the line at the transmatch, tune and go. It's a great way to tune the transmatch in any event because you needn't use your transmitter power. I use the 40 meter version of the 2XZepp, which has an overall length of roughly 167 feet. It loads all bands 160 through 10. I use a home-brew transmatch that has considerably greater flexibility than any commercial versions, which is the reason I can actually load the 2XZepp properly on 160 rather than simply tying the feed lines together and using it as a top-hat vertical. If you've got the room, it would be interesting to try the 80 meter version. Rather generally, however, a good principle for all-band wire antennas is: get as much wire in the air as possible up as high as possible (don't worry about resonance); feed with open wire line to a transmatch. Also, within a wide range, you needn't worry too much about feeder length. With a properly designed transmatch you can accommodate what variation you need with coil taps. The 2XZepp is amazingly effective. It does, in theory, have lots of lobes on the higher bands, so you may have some problems in some directions, but, at the same time, you will have great results in other directions. On the lower bands, the antenna also pumps a lot of energy at a high angle of radiation, unless you are able to put it hundreds of feet into the air. But I have not found this to be a practical problem. I'm all over Europe, east and west, with 5 or 10 watts and getting excellent reports. I suspect this angle-of-radiation thing is somewhat misplaced anyway. My experience accords more closely with the newer notion of propagation that has radiation breaking out of paths that parallel the earth rather than bouncing up and down like rubber balls. Furthermore, the higher angle of radiation is excellent for local qso's, which, for rag chewers, is salubrious. If you want to avoid the transmatch, consider a set of parallel dipoles, but using the transmatch is really very easy and fast once you get your initial settings, and you are not making compromises at every turn. best wishes, dave belsley, w1euy - --On Thursday, April 5, 2001 8:40 AM -0500 Tony Parks wrote: > Now that I have K2 #1939 working well I am looking for a good 80 through > 10 wire antenna. I am on a farm so antenna length is not a problem.. I > would appreciate hearing what has worked for other K2 owners. > > Thanks! > > Tony > KB9YIG ++++++++++++++++++++++++++++++++++++++++++ Date: Thu, 5 Apr 2001 13:42:43 -0400 From: "Eagerman, Sumner" Subject: [Elecraft] For field collapsible poles in portable situations consider using "hot Sticks" used by linemen in the power utility industries. These poles are very sturdy, easily extended and collapsible and are available up to 50 feet or so. I strongly recommend purchasing the triangular shape poles for they are easier to lock into place, as you extended each section, over the round poles. These pole can be purchased through distributors like Graybar, Wesco or other electrical houses serving the power industry. 73 Sumner WA1JOS K1 #615 not yet born +++++++++++++++++++++++++++++++++++++++++++++++++ Date: Fri, 6 Apr 2001 12:54:40 -0500 From: "Jim" Subject: [Elecraft] SD-20 works great - Extendo Pole = better price? I already have the Black Widow 20ft pole. I've used it on the beach, and in my north 40 field with great results. I searched http://www.thesportsauthority.com/ and found an even price for a 20ft pole. Its called the South Bend Extendo Pole. At $14.97 the price is right. Looking at the best picture they have, it looks just like what I have here. http://www.thesportsauthority.com/product/index.jsp?productId=8449&position= 4 I didn't make the SLV. I just cut a 14.060mHz 1/4 wave stinger and two radials. I soldered the bottom of the stinger to a so239, and soldered a 3" lead wire to one of the ground holes on the so239 coax connector. There is an eye loop at the top of the pole, where I tie the top of the stinger. On 20M the pole is just long enough so everything fits great. I stab a 2ft long piece of construction rebar in the sand and slide the big end of the pole down on that. This is all it takes to keep the pole standing tall. Some old fiberglass 24" tent poles are stuck in the ground 1/4 wave length away from the base of the pole 180 degrees from each other. The 2 radials are off the ground, and perform better that way. To change bands, I have a twisted wire connection I can separate and the stinger then becomes resonant for 21.060mHz. At the twist point I have knots tied in the wire, and a piece of string holds both sections together, but dos'nt allow the wires to touch. I then roll up the radials for 1/4 wave, at 21mHz, and I have knots tied at the proper length on each radial for best SWR. When I go portable I keep it simple and chose two bands. Doing more than that when portable gets too complicated for my tastes. Check out some pics of my portable QRP-QRPp setup at my webpage. The antenna can be seen there, but not in great detail. http://sunwatt.homestead.com/slategap.html But it might give you some idea of how simple this antenna is. 73's de Jim KJ5TF "All Milliwatts, All The Time" http://sunwatt.homestead.com/Main.html ++++++++++++++++++++++++++++++++++++++++++++++ Date: Mon, 9 Apr 2001 08:47:57 EDT From: DLShips at aol.com Subject: [Elecraft] Effective, Quick and Easy 15 meter portable antenna Guys, I been having a lot of fun at the picnic table on my deck with the K1 and this quick and easy antenna. Saturday I was all over the place, Alaska, Poland, England, Utah, CO, etc. It requires little effort, no ground return and NO TUNER. You guessed it, it's a delta loop and the bottom is fairly close to the ground (within 5 feet). It's shape is equilateral and It's tied to the railing on the deck with a foot of nylon cord. I'm feeding it with 3 ft of 50 ohm coax and the top of the antenna wraps over nicely spaced oak tree branches. I suggest a coat button at the feed point. You can tie each end of the loop to a hole in the button and the string can be looped through the bottom two holes. The whole antenna takes about 47 ft of insulated hookup wire and I'm using alligator clips at the end of the coax for quick connection. I started with the formula of 1005/21.06 but upon checking it with the RF Analyst I had to clip at least a foot of wire before I got a good 50 ohms at 21060 and the lowest possible vswr. For those of you struggling with antenna choices, and if you have the right setting, this one is a winner. 72/73 de Don, W3RDF Builder of the following Elecraft K2 Kits: S/N 0041 - NB - ..............................BATT S/N 0479 - NB - ATU - SSB - 160m S/N 0611 - NB S/N 0704 - NB - ATU - SSB - ...........BATT S/N 0926 - NB - ATU - SSB S/N 1049 - NB - ATU - SSB - 160m - BATT S/N 1205 - NB - ATU - SSB - 160m S/N 1325 - ........ATU - SSB S/N 1500 - NB - ATU - SSB - 160m S/N 1575 - NB - ATU - SSB - 160m - BATT S/N 1714 - .................SSB S/N 1911 - NB - ATU - .....................BATT .................NB......................160m..........(for S/N 0557) Builder of the following Elecraft K1 Kits: S/N 0116 - Extra band pack S/N 0395 S/N 0500 S/N 0560 - ATU +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Date: Tue, 10 Apr 2001 10:54:07 -0400 From: Charles Greene Subject: [Elecraft] Antennas for Field Use Hi All, I have seen some discussion recently about antennas for field use with matching networks and thus. The NJQRP Squirt which is a 1/4 flat top on 80 fed with ladder line is one, and there's and article on a 1/3 wave length antenna in Sept 98 QST fed with ladder line and there are some others. All have some kind of matching network and tune "all bands." This is great for some of the QRP rigs, however, K2 owners with a KAT2 have a matching network built in. What is needed is a balun at the end of the ladder line and a short length of coax to the K2. Since the loads at the end of the ladder line can vary from a few ohms to a few hundred ohms, a 1:1 balun is about as good as any. My present antenna for portable operation is a 34' flat top (1/2 wave on 20) fed with #24 twisted pair wire I extracted from a telephone cable, however nearly any length of flat top antenna fed with ladder line or a substitute is going to work. You should keep the length of 1/2 the antenna length plus the feed line electrical length not equal to 1/2 wave length on any band of operation as that will give you a current node and a high voltage point with high SWR that is hard to match. The 1:1 balun I am using is simple constructed of 8 turns of RG174 coax wound on a FT82-43 toroid with a 12" length and a BNC for the K2 and a couple of inches with alligator clips for the twisted pair. If you go more than a few feet to get to the K2 use a coax with lower loss than the RG-174. Just thought I'd try to dispel some of the "magic" of some of the current antenna systems and offer my thoughts on what works. 73, Chas, W1CG +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Date: Tue, 22 May 2001 08:19:27 -0700 From: Eric Swartz WA6HHQ - Elecraft Subject: Re: [Elecraft] Superantennas MP-1 I put longer radials on it, especially for 40M. 73, Eric Julian wrote: > > Some months ago, I bought an MP-1 antenna with tripod for portable use. > > Since getting the KBT2 option in my K2 it has become apparent that in my > experiments, the antenna was seeing a ground through the radio itself. ... > > I'm sure I heard of the MP-1 first on this list, so there must be other K2 > users who use it as a portable antenna. How do you use it? Do you ignore > the SWR, just tune for maximum noise and then let the KAT2 take care of the > match? Or should I be trying longer radials, more radials, resonant length > counterpoises of something? I am at the point of giving up on the MP-1 as > an expensive mistake and would appreciate any advice. > >Julian, G4ILO. (RSGB, ARRL, K2 #392) ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Date: Tue, 5 Jun 2001 15:17:24 -0500 From: "Stuart Rohre" Subject: Re: [Elecraft] Field Day Blues The preferred way to get into canyons and jungles is HF NVIS, Near Vertical Incidence Skywave, which is done with very LOW antennas, such as a dipole 10 feet up, or less. This can give you state wide coverage over most of Texas for instance, no mean feat. 80 and 40 are used statewide here for most of our state disaster nets. 40 for days, and 80 for nites. If the hams get the new band at 5 MHz, that should be ideal for NVIS uses. While stationed in Malaysia, I had an associate who established an NVIS SSB network for jungle penetration to the scattered hospitals in aborigine country. He had to fly out to check on technical issues with the field radios,and did this by a not very reliable chopper. When it would have its periodic engine tantrums, they would set down on a clear spot such as a river bank, and he would roll out, and hang on bushes, an 80m dipole he carried for just such occasions when the aircraft VHF radio was out of range, and on the ground too low under the forest canopy to work. He would take one of Don Stoner's radios which is what they bought for the SSB net, and call home base for a repair chopper. With mobiles, the military is folding over their HF whips to get NVIS coverage. Hams could adapt the fold over whip pivot joints for clearing parking garages and do the same. 72, Stuart K5KVH ++++++++++++++++++++++++++++++++++++++++++++++++++++ Date: Mon, 18 Jun 2001 15:26:19 -0500 From: "George, W5YR" Subject: Re: [Elecraft] K1 antenna(s) Steve, if you can stand the extra length, making the flat-top 88 ft instead of 66 ft might avoid a lot of tuning problems plus give you up to 3 db gain on 20 meters and allow the antenna to be used on 80 - 10! On 20 meters, your 40-meter dipole is going to present a very high Z to the feedline which depending upon its length, etc. could present a very awkward Z and voltage/current levels for the rig. And there is always the possibility with internal tuners of excessive voltage/current at the tuner terminals causing damage. I gave up on multi-band "resonant" antennas a long time ago . . . 72/73, George W5YR - the Yellow Rose of Texas QRP-L 1373 NETXQRP 6 Fairview, TX 30 mi NE of Dallas in Collin county EM13qe Amateur Radio W5YR, in the 55th year and it just keeps getting better! Icom IC-756PRO #02121 Kachina #91900556 IC-765 #02437 Steve Lawrence wrote: > > Bob, > I'm about to venture into the field with a ladder-line fed dipole, cut for > 7.150 mHz. Experiments seem to indicate that the K2 tuner (yes, I > understand you have a K1) will tune this setup on 40M and higher. The > antenna is simple, I guess I can hang it as an inverted-V or a traditional > horizontal dipole. ++++++++++++++++++++++++++++++++++++++++++++ Date: Mon, 18 Jun 2001 16:47:01 -0400 From: "ZOOM" Subject: Re: [Elecraft] K1 antenna(s) Bob grounding is very critical with wire antennas. You can put out as much wire as you want but if it's not grounded well, it will be a poor performer. A great reference is the ARRL antenna handbook. If you don't have one, someone in your area may and perhaps lend it to you. Failing this, your local library may have a copy for loan. Also for portable use, I found using a hustler mobile antenna with three aluminium struts for ground radisl works very well. I put both elements on a makshift holder and it's fairly broadband. 20/40 elements Cheers, Robert VE3RPF K1 #455 - ----- Original Message ----- From: "Bob Garske" To: Sent: Monday, June 18, 2001 1:13 PM Subject: [Elecraft] K1 antenna(s) > To the K1 gang, > > > I am building a K1 for 40 and 20 meters, with the built in tuner. > Finishing up the RF board this week. I love it so far. > > Please contact me with antenna suggestions for a (PORTABLE) DUAL BAND > WIRE ANTENNA with easy set up and take down for these 2 bands. > > I prefer a single antenna that I can use either as an "Inverted V", fed > with RG-8x, (possibly with small alligator clips to add the extra dipole > sections) or ????? > > A random length wire, on an incline, (tossed up into a tree at one end) and > fed with the built in tuner would be ok, but I have NO experience with this > type antenna and don't know how it would perform as compared to a pair of > dipoles, cut for each band. > > I would like to correspond with any who recommend antennas. > > > Thanks and 73, > > Bob, K9JMP K1 #746 ++++++++++++++++++++++++++++++++++++++++ Date: Mon, 18 Jun 2001 14:26:54 -0700 From: "Ron D' Eau Claire" Subject: RE: [Elecraft] K1 antenna(s) Steve, AA8AF wrote: I'm about to venture into the field with a ladder-line fed > dipole, cut for > 7.150 mHz. Experiments seem to indicate that the K2 tuner (yes, I > understand you have a K1) will tune this setup on 40M and higher. The > antenna is simple, I guess I can hang it as an inverted-V or a > traditional > horizontal dipole. > > I am pretty much convinced that an antenna like this represents a lot of > pluses... Good points. Actually, the antenna will be quite efficient as long as it is at least 1/8 wavelength overall. That is, an antenna cut for 40 will work well on 80 meters as well with only a small loss in efficiency. The usual problem with a horizontal antenna on the lower bands is height above ground. You want it 1/2 wavelength up if you can get it, and at the very least 1/4 wave high for it to put out much of a signal except straight up. That's a bit over 30 feet on 40 - pretty easy to arrange most places - but it's 60 feet on 80! If you are hanging it 'inverted vee' style, the effective height is about 80% of the peak height at the center, so the center needs to be proportionately higher. The issue with the balanced feed is converting the K2 or K1 tuner output to balanced feed. Most ops use a balun, which works as long as the feedpoint impedance isn't too awfully high or low. The balun quits working at extreme impedance's, and can act as a great dummy load at times, letting the rig tune up nicely but not putting out much of a signal. Probably the easiest way to alter the impedance at the feedpoint is to change the length of the feedline if needed. For only two bands, as the original question posed, a dual dipole (one feedline with two dipoles connected to the feedline each cut to 1/2 wavelength) can work very well. They are trickier than most realize to cut so you have a very low (less than 2:1 SWR) on both bands, but the ATU in the K1 or K2 will take care of the SWR on the feedline so it's not an issue. Just cut them to 'textbook' length (468/f(MHz)). If one uses good feedline (no RG-174 miniature coax!) the dual dipoles won't create a high enough feeder SWR to cause significant losses. RG-58 for a reasonably short run or larger lower loss coax for longer runs is easier to deal with than the open wire line for most ops, and it does not require a balun. Ron AC7AC K2 # 1289 ++++++++++++++++++++++++++++++++++++++ Date: Mon, 18 Jun 2001 20:38:21 -0400 From: "Francis Belliveau" Subject: Re: [Elecraft] antenna(s) On: Monday, June 18, 2001 1:13 PM "Bob Garske" wrote: > > I am building a K1 for 40 and 20 meters, with the built in tuner. > Finishing up the RF board this week. I love it so far. > > Please contact me with antenna suggestions for a (PORTABLE) DUAL BAND > WIRE ANTENNA with easy set up and take down for these 2 bands. > > I prefer a single antenna that I can use either as an "Inverted V", fed > with RG-8x, (possibly with small alligator clips to add the extra dipole > sections) or ????? > Since you are interested in a dipole style I suggest that you read the page at http://www.cebik.com/aledz.html There is an excellent description of how to cut a single dipole for multiple bands. My choice to satisfy the above would be to cut it for 40. His data shows that good results can be expected on the two bands when cut for either 67 feet or 44 feet. The difference is that 44 feet does better on other bands. My suggestion would be to not carry RG-8. It is too heavy. If that is not a concern then okay. I would use twin-lead to keep the feed-line light and the losses low. Fran ++++++++++++++++++++++++++++++++++ Date: Mon, 18 Jun 2001 20:18:19 -0700 From: "Ron D' Eau Claire" Subject: RE: [Elecraft] K1 antenna(s) Bob wrote: > A vertical antenna, OTOH, is a much different situation. I've wondered > for decades why people use vertical antennas at all on HF. A vertical can out-perform a very low dipole (less than 1/4 wave above the ground), at least in terms of radiation any direction but 'straight up' and I've used them when I was limited that way. If you make the 'vertical' 1/2 wavelength long (or close to it) it can be very efficient with a very simple ground. Of course that means a tall antenna - or losses in coils or other loading contraptions. But if you can get a horizontal dipole up a decent height - up close to 1/2 wavelength high, the gain produced by the ground reflections will beat a vertical by a big margin! I did some testing and modeling of my limited home QTH setup. With a dipole at only 20 feet high, a vertical beat the horizontal on 40 meters. But with the horizontal up about 25 feet or so, the tables start turning and the horizontal beats the vertical and the difference grows very quickly in favor of the horizontal as it moves toward 1/2 wavelength high. One way a low dipole (or inverted vee) us used to great effect by some portable ops is to hang it off of the side of a cliff. A low dipole has lots of gain straight "up" and if it is hanging off the side of a steep incline, "up" becomes out towards the horizon and DX. I've seen one installation where the op used a short pole and some line. the pole stuck out at about 70 or 80 degrees from the vertical on a steep mountainside incline and was kept from falling by one line going to a tie-off further up the side of the mountain. The dipole was hung as in 'inverted vee' with the ends stabilizing the pole side to side. It reportedly worked lots of DX on 20 meters with only a 10 foot supporting pole. Ron AC7AC K2 # 1289 ++++++++++++++++++++++++++++++++++++++++++++ Date: Tue, 19 Jun 2001 08:48:50 -0400 From: "Mark J. Dulcey" Subject: Re: [Elecraft] K1 antenna(s) Mike wrote: > > A vertical antenna, OTOH, is a much different situation. I've wondered > for decades why people use vertical antennas at all on HF. ON4UN's book on Low Band DXing supplies a number of good reasons. Basically, they're the easiest way to get low-angle radiation on the lower HF bands (though you need to lay a lot of ground wire to get the best possible performance out of them), and therefore can be highly effective antennas for DX work. Not many hams can get an 80m or 160m dipole up high enough for low radiation angles, and Yagis for those bands are large and difficult to build, especially if you want them to be able to rotate. Verticals are also popular at DXpeditions, perhaps in part because the excellent ground that many of the popular DXpedition sites have (what with being located near beaches; on the smaller islands, you can't help being near one) means that verticals perform well, even with minimal grounding systems. On the other end of the scale, there are issues of neighborhood acceptance of your antenna system, or feasibility of erection in a small lot. A base-fed flagpole, for instance, has been used by a number of hams as an effective antenna in locations that don't allow antennas. And a simple roof-mounted ground plane for 10-20 meters can be put up even if you have no yard at all, whereas a dipole or other wire antenna needs SOME real estate. Now, if you'e strictly talking about PORTABLE antennas, you have a stronger case - except possibly for locations where there are no antenna supports available at all, and especially ones with good ground like the seashore. If I were going to operate portable from a beach, I might well pack a vertical and a small ground rod. +++++++++++++++++++++++++++++++++++++++++ Date: Sat, 23 Jun 2001 19:11:20 -0400 From: Jim Wineteer Subject: [Elecraft] k1 portable antenna Hi Gang, I don't have a k1, but I built an antenna that some of you would find suitable. I had a roll of 450 -ohm ladder line lying around here, but my blt was giving me grief so I searched the web for g5rv plans that used 450 ohm. I found ZR1DQ's website on a g5rv modified for modern ladder line and coax using a computer modeling program. I got the dimensions in metric, but I would have been willing to convert if the article actually covered my 450 ohm ladder line. I called radio works and asked if they knew what the velocity factor was, I was going to adjust the dimensions. But they didn't have it, and I wasn't about to drive out to work to shoot it with a TDR, so I got back on the web and found n5crk's page from another search engine. I built an antenna from his plans. It's 90' 3'' in the horizontal, and vertical element is 40' 450 ohm ladder line (it's a tranformer not just transmission line) into an unmeasured scrap of rg58 with a bnc already on one end. My antenna won't do 15 M, but 80- 40- 20- 17- 12- 10?? were fine with ATU2, and I think a pair of bands would be fine even with no tuner, if someone was willing to do some measuring and pruning. I hate hearing a dx beacon or long distance freebander on ten when I don't have any hams to work, but it rx'd fb there too. http://www.qsl.net/zr1dq/antenna-202.htm http://n5rck.tripod.com/wireband.html 73's Jim ++++++++++++++++++++++++++++++++++++++ Date: Sun, 24 Jun 2001 12:11:53 +0200 From: "Ingo DK3RED" Subject: [Elecraft] Re: k1 portable antenna Hello Jim, > ... I got the dimensions in metric, > but I would have been willing to convert if the article actually covered my > 450 ohm ladder line. I called radio works and asked if they knew what the > velocity factor was, I was going to adjust the dimensions. But they didn't > have it, and I wasn't about to drive out to work to shoot it with a TDR, so > I got back on the web and found n5crk's page from another search engine. > I built an antenna from his plans. ... Please see on http://www.g3ycc.karoo.net/g5rv.htm There are the dimensions adn velocity factors for different lines. 72 de Ingo, DK3RED +++++++++++++++++++++++++++++++++++ Date: Sun, 1 Jul 2001 10:03:29 +0200 From: "Dieter Klaschka" Subject: [Elecraft] dipole -vertical Ken wrote ......................snip................... This week end I set up this vertical antenna and my new 44 ft dipole with 22 ft of 300 ohm twin lead (NO BALUN) and tuned each with the KAT2. I could compare them with the push of the ANT button and I was in for a surprise. The dipole almost always was stronger and had less QSB. I also gained back 30 and 40 meters. The dipole was only 10 ft off the ground using PVC pipe for supports while the vertical was the 16 ft piece of copper pipe and the 16 ft trailer frame counterpoise. I also tried my ZM-2ATU and it works well but ........ ......................snip............... Hi, Ken, Do you mean a dipole 2x22 ft or the Extended DZ with t w o 44 feet legs (that's ca 13,41 m each if I am right) ??? There was a short contribution of DF2OK on the DL QRP server who mentioned that not all lengths of feeders will do a pretty good job. He added the figures of which he heard that those "were playing well" 34,60 m 40,50 m 54,00 m 64,80 m Your experience with the Zmatch tuner described seems to confirm that. In this connection there has been a discussion on the best way to find and construct the rungs (?) /steps/spreaders of the chicken ladder/feeder: So far some results which differ from possibly known ones: - -take the small slender plastic squeezers from the stationeries which hold single paper/pages packs - -take plastic pieces cut from plastic forks used for camping - -take stripes from check cards (old ones I hope or not your own at least) - -take parts of thin plastic tubes used for moving curtains - - take stripes of plastics which are used in forms at bakeries to seperate cake from metal form - -SPRAT informed about using nylon strings used for weed wackers handled with an iron and hot glue (AA1MY) - -the icing on the cake: take stripes from small pipes which are used in industry for pneumatic or hydrolic connectors; small diametre pipes which are used for automatic watering flower pots in garden centers or at home may also do. Cut holes with a special pair of pliers (saddlers's equipment, will be found in the same DIY shop I think, pricy) The wires could then be fixed with a drop of glue easily - no drilling!!! Could you add some more? Cu.73! Dieter.dl2bqd ++++++++++++++++++++++++ Date: Sun, 1 Jul 2001 12:18:39 -0500 From: "Kenneth Christiansen" Subject: [Elecraft] 44 ft Dipole with 22 ft feed line Subject: Re: [Elecraft] K2 At 09:36 06/07/2001 -0700, Daryl Cline wrote: >Also I am interested to know what >different people use for light weight antenna systems. >Especially those who backpack. Thanks. Bonnie Crystal KQ6XA Has come up with this clever and very versatile design for a portable wire antenna, it works a treat with the K2's internal ATU see http://www.qsl.net/kq6xa/antenna/ I have a short piece of coax with 2 banana plug sockets on one end and a BNC plug on the other end to connect my miniback to the K2, no need for a balun with the K2 if you have the ATU installed. Bonnie's main page is at http://www.qsl.net/kq6xa/ The K2's internal tuner Is REALLY good, It matches everything I have ever tried it on, It even matched a 2m rubber ducky on 40m, I even managed a local (~4 Miles) QSO with the Rubber ducky. You will not regret choosing a K2. - -- Brendan Minish EI6IZ ei6iz at oceanfree.net PGP key available from key servers wwwkeys.pgp.net +++++++++++++++++++++++++++ Date: Fri, 24 Aug 2001 22:03:21 -0700 From: Jeff Stai WK6I Subject: Re: [Elecraft] Antennas and other rambling (Elecraft-related, of course!) The C3SS is a FINE antenna, but I would hesitate to spin it on a TV rotator. The hexbeam looks more appropriate for that use. (I do need a portable solution myself and I hadn't remembered the Hexbeam. If I can convince myself that band changes can be quick, I might go for it. thanks!) - - jeff wk6i At 07:53 PM 8/24/01, Mark J. Dulcey wrote: >John Clifford wrote: >>Greetings, >>I'm looking to buy some sort of small beam for 20m and up. Practical >>considerations prevent me from going the huge tower route (it WILL happen >>sometime in the future!), but I'd like to get something 30' AGL or more >>without offending the neighbors or the wife. Based upon the reviews on eHam >>the short list consists of the Butternut Butterfly, the Cushcraft MA-5B, and >>the TGM Mini-Quad. These (or something similar in size) were chosen also >>because they are not much bigger than the non-used TV log periodic antenna >>currently shading the chimney, and they can be turned by a TV rotor. My >>goal is to get something up that will outperform a static dipole hung at the >>same height. > >If you've got the budget, other candidates would include the Force 12 C-3SS and the Traffie Technology Hexbeam. They're both rather expensive, but the reviews are favorable. They're a bit bigger than the others you named, but still significantly smaller than a standard tribander. > >Based on what I've heard, one antenna to avoid is the Mosley Mini-33. jeff stai radio stuff: WK6I in DM13 rocket stuff: NAR #21059 TRA #3356 Level 2 Cert. email: jstai at home.com or wk6i at arrl.net ROC web page: http://www.rocstock.org/ LDRS web page: http://www.ldrs20.org/ +++++++++++++++++++++++ Date: Sat, 25 Aug 2001 10:28:28 +0200 From: "lpec" Subject: [Elecraft] RE: 20 Mhz and up antenna Hallo all, I'm ussing since a while a D2T all band antenna, look at www.antenna.it Hams, D2T It works vy well above 14 Mhz also on 6 Mtr.s and 2 Mtr Gain aprox 4 a 6 db turnable with TV rotor see testrapport 72/73 de Bert PA0LPE 8Q7PA K2 # 1077 # 2139 +++++++++++++++++++++++++ Date: Mon, 27 Aug 2001 17:34:45 -0400 From: Bill Coleman Subject: Re: [Elecraft] Antennas and other rambling (Elecraft-related, of course!) On 8/24/01 1:29 PM, John Clifford at johnclif at ix.netcom.com wrote: >I'm looking to buy some sort of small beam for 20m and up. Practical >considerations prevent me from going the huge tower route (it WILL happen >sometime in the future!), but I'd like to get something 30' AGL or more >without offending the neighbors or the wife. Based upon the reviews on eHam >the short list consists of the Butternut Butterfly, the Cushcraft MA-5B, and >the TGM Mini-Quad. I owned a Butternut HF4B. I'm familiar with the MA-5B. I used to have the HF4B up. I replaced it with a Cushcraft A3S. The A3S is nearly twice as big as the HF4B, but it performs more than twice better. The MA-5B is similar in size to the A3S. The specs speak for themselves. The MA-5B looks like a poor compromise to get 5 bands. You can turn an antenna the size of an A3S (14 foot boom) with a TV rotator. I'd recommend the in-line type (old CDE AR22 / 44). I used an AR22 for 8 years, and it worked great. There are other small beams of this type. The TA33jr, the TH2 and TH3 come to mind. You might look for one of these types on the used market. These tribander designs are 20 or more years old, but they still perform OK. Bill Coleman, AA4LR, PP-ASEL Mail: aa4lr at arrl.net Quote: "Not within a thousand years will man ever fly!" -- Wilbur Wright, 1901 +++++++++++++++++++++++ Date: Mon, 27 Aug 2001 18:36:12 -0400 From: "Anthony A. Luscre" Subject: Re: [Elecraft] Antennas and other rambling (Elecraft-related, of course!) Bill Coleman wrote: --snip--- > > There are other small beams of this type. The TA33jr, the TH2 and TH3 > come to mind. You might look for one of these types on the used market. > I would add two additional items to your list- Sommer Log-Yagis X403 or x500. The X403 has an 8 ft boom and X503 has a 15 boom. I have the X508 and it has been great, quality construction, quality workmanship and great performance. Although the x500 series may too big take a look at x400 at http://www.sommerantennas.com/ - -- |--------------------------| Anthony A. Luscre K8ZT Stow, Ohio |--------------------------| ++++++++++++++++++++ Date: Mon, 27 Aug 2001 17:48:00 -0500 From: "Stuart Rohre" Subject: Re: [Elecraft] Antennas and other rambling (Elecraft-related, of course!) The A3 is a good beam, I have used one at Field Days in the past. For any used beam it makes a big difference to clean their overlapping joints up with a Scotch Brite pad, then apply No Ox or similar anti oxidation grease immediately. Trust that any beam that sat up for awhile needs clean up before use. Especially smaller beams Like the TA 33 Jr. or A3, that have smaller diameter elements. Surface area resistance is everything to their good working. Aluminum oxidizes immediately after cleaning, thus the grease must be ready to go, and put on as you finish each joint. Also, make sure you have the right instructions and trap positions for any used antenna, and mark the settings on the elements for the favorite band Voice or CW. Many times beams are hauled out to Field Days without adequate instructions, assembled in what seems a logical manner, only to not work well, because of trap reversals, or wrong element lengths or spacing. Finally, feeding some older beams requires the right matching balun, or substitute, or a properly wound cable choke without the first and last turns touching, or in the case of old Mosely beams, you can connect coax right to the split driven element without a balun! I did not believe that was right, but confirmed it with a factory engineer, who also added that a cable choke of wound up coax would not hurt, if kept symmetric to the element center. 72, Stuart K5KVH ++++++++++++++++++++ Date: Mon, 27 Aug 2001 21:39:02 -0400 From: "Mark J. Dulcey" Subject: Re: [Elecraft] Antennas and other rambling (Elecraft-related, of course!) Anthony A. Luscre wrote: > > I would add two additional items to your list- Sommer Log-Yagis X403 or x500. > The X403 has an 8 ft boom and X503 has a 15 boom. I have the X508 and it has been > great, quality construction, quality workmanship and great performance. Although > the x500 series may too big take a look at x400 at http://www.sommerantennas.com/ Although the XP403 has only an 8 ft. boom, it weighs 40 pounds and has a wind load of 6.8 sq. ft. That's a lot higher than the other antennas people have been discussing; probably too much for a TV rotor or simple roof mount. It also has 35 foot long elements, which are rather large. Aside from that, it looks like a fine antenna. Most of the antennas that have been under discussion have reduced length elements. Aside from the reduction in weight and wind load, the reduction of visual impact may be important in some applications. A really small antenna like a Mini-Quad or MA5B is likely to attract less attention from the neighbors than a full-size tribander. Let's compare the statistics of some reduced-size contenders: Antenna Element len Boom len Weight Wind load TGM MQ-1 11' 4.5' 16 lb. 1.5 sq. ft. TGM MQ-2 12.1' 4.5' 17 lb. 1.6 sq. ft. TGM MQ-3 11.4' 10.2' 22 lb. 2.6 sq. ft. TGM MQ-4 12.1' 10.2' 26 lb. 2.8 sq. ft. Mosley Mini-33 16.7' 6' 10 lb. 2.5 sq. ft. Mini 33-A-WARC specs not yet on Mosley web site Butternut HA-5B 12.5' 6' 22 lb. 3 sq. ft. Cushcraft MA-5B 17.1' 7.3' 26.5 lb. 3.22 sq. ft. Hexbeam HX-5Bi 18.8'* 18.8'* 19.5 lb. 5 sq. ft.* Force 12 C-3SS 27' 11.7' 27 lb. 4.4 sq. ft. Sommer XP403 35.3' 8' 40 lb. 6.8 sq. ft. * the Hexbeam isn't directly comparable in size or wind load to other antennas, due to its unique shape. Its effective wind load is reported to be less than its actual frontal area. And some small full-size tribanders for comparison: Mosley TA-33M 28' 14' 37 lb. 5.7 sq. ft. Cushcraft A3S 27.8' 14' 30 lb. 4.4 sq. ft. Force 12 C-3S 37.5' 11.7' 26 lb. 5 sq. ft. Hy-Gain TH-3JRS 27.2' 12' 21 lb. 3.35 sq. ft. Hy-Gain TH-3MK4 27.4' 14' 35 lb. 4.6 sq. ft. I'm not trying to compare performance of these antennas, just size. All specs are from the manufacturers, and the weights are a mixture of shipping weight and "installed weight"; some manufacturers give one, some the other. The C-3SS is listed as a "reduced size" antenna because it's smaller than the standard Force 12 antenna - but it's as big as a lot of the full-size tribanders. Meanwhile, the TH-3JRS has a low enough wind load rating that it might be a good alternative to the reduced size antennas, despite being a nearly full-size tribander. +++++++++++++++ Date: Mon, 27 Aug 2001 23:52:27 -0400 From: Bill Coleman Subject: Re: [Elecraft] Antennas and other rambling (Elecraft-related, of course!) On 8/27/01 9:39 PM, Mark J. Dulcey at mark at buttery.org wrote: >Let's compare the statistics of some reduced-size contenders: > >Antenna Element len Boom len Weight Wind load > >TGM MQ-1 11' 4.5' 16 lb. 1.5 sq. ft. >TGM MQ-2 12.1' 4.5' 17 lb. 1.6 sq. ft. >TGM MQ-3 11.4' 10.2' 22 lb. 2.6 sq. ft. >TGM MQ-4 12.1' 10.2' 26 lb. 2.8 sq. ft. >Mosley Mini-33 16.7' 6' 10 lb. 2.5 sq. ft. >Mini 33-A-WARC specs not yet on Mosley web site >Butternut HA-5B 12.5' 6' 22 lb. 3 sq. ft. >Cushcraft MA-5B 17.1' 7.3' 26.5 lb. 3.22 sq. ft. >Hexbeam HX-5Bi 18.8'* 18.8'* 19.5 lb. 5 sq. ft.* >Force 12 C-3SS 27' 11.7' 27 lb. 4.4 sq. ft. >Sommer XP403 35.3' 8' 40 lb. 6.8 sq. ft. > >* the Hexbeam isn't directly comparable in size or wind load to >other antennas, due to its unique shape. Its effective wind load >is reported to be less than its actual frontal area. > >And some small full-size tribanders for comparison: > >Mosley TA-33M 28' 14' 37 lb. 5.7 sq. ft. >Cushcraft A3S 27.8' 14' 30 lb. 4.4 sq. ft. >Force 12 C-3S 37.5' 11.7' 26 lb. 5 sq. ft. >Hy-Gain TH-3JRS 27.2' 12' 21 lb. 3.35 sq. ft. >Hy-Gain TH-3MK4 27.4' 14' 35 lb. 4.6 sq. ft. Beware comparing measurements of "wind load". Not all manufacturers use the same units. (Ask yourself, "Square feet of what?") >The C-3SS is listed as a "reduced size" antenna because it's >smaller than the standard Force 12 antenna - but it's as big as a >lot of the full-size tribanders. The key is the reduced boomlength. Other things being equal, the gain realizable in a yagi antenna has nearly nothing to do with the number of elements, and is proportional to the boom length in wavelengths. Tribanders represent a compromise in optimal element placement. The A3S has a wide element spacing on 10m (.2 wl), but much shorter on 20m (.1 wl). The Force 12 designs are superior to many of these old trapped yagis because they opt for more optimum spacing of the elements. The C3SS really only uses two elements per band. (It is three 2 element beams colocated on the same boom) >Meanwhile, the TH-3JRS has a low >enough wind load rating that it might be a good alternative to >the reduced size antennas, despite being a nearly full-size I think any of the antennas you list with a 10-14 foot boom length would be good performers, certainly better than anything with a 6-8 foot boom. There's also another class of tribanders with 15-24 foot booms (KT34A, Cushcraft A4S), as well as another class with 25-up foot booms (KT34XA). I would divide these into four classes: Short: 6-8 foot boom Small: 10-14 foot boom Medium: 15-24 foot boom Large: 25-up foot boom I wouldn't recommend anything in the Short catageory, unless there's no way you can fit a Small tribander. Bill Coleman, AA4LR, PP-ASEL Mail: aa4lr at arrl.net Quote: "Not within a thousand years will man ever fly!" -- Wilbur Wright, 1901 ++++++++++++++++ Date: Tue, 25 Sep 2001 18:22:52 -0500 From: "Stuart Rohre" To: Cc: Subject: [107487] Antennas for steel pole Message-ID: <010701c14618$ffd3baf0$4e100a0a at rohredt2000> Mark, Just go to Radio Shack. Get the TV twin line standoffs, and attach to pole, run twin line to G5RV as an inverted Vee, or to a doublet and you are in business. A transmatch at the shack takes care of matching, you can run twin all the way. Second best dipole like length would be 88 feet center fed as above. 72, Stuart K5KVH ++++++++++++++++ Date: Tue, 25 Sep 2001 19:19:10 -0500 From: "George, W5YR" To: rohre at arlut.utexas.edu Cc: Low Power Amateur Radio Discussion Subject: [107490] Re: Antennas for steel pole Message-ID: <3BB11EFE.AF3A7FEA at att.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit I also use a steel pole to support the centers of two 20-meter EDZ antennas, each 88 ft long. I simply pull the ladderline to one side and secure it to the edge of the roof to keep it away from the pole. I would argue that the 88 ft antenna will outperform the G5RV on 20 meters since it provides 3 db gain which the 1.5 wavelength G5RV cannot. I use two of the EDZs mounted at right angles. They work well on 80-10. Feed is ladderline to W2DU balun to coax to tuner. 72/73, George W5YR - the Yellow Rose of Texas QRP-L 1373 NETXQRP 6 Fairview, TX 30 mi NE of Dallas in Collin county EM13qe SOC 262 Amateur Radio W5YR, in the 56th year and it just keeps getting better! Icom IC-756PRO #02121 Kachina #91900556 IC-765 #02437 +++++++++++++++++++