If anyone is really interested in any kind of operational review of the Isotrons, go to their web site isotronantennas.com and read the reviews that were published years ago in 73 magazine. There are other reviews too. I am sure that you can find operational scenarios that are in good prop periods that the person has worked the world. But how do they perform as a general antenna in an average amount of typical ham on-air time?
On Tue, Dec 22, 2020 at 9:37 PM Jonathan Guthrie via BVARC <[email protected]> wrote: > I'm not sure that it's that they don't know any better, but that it > suffices for their needs. If you don't have a specific purpose in mind, > other than make contacts, and you have a limited amount of space, why not > use it? Would a much larger antenna really be much better in that case? I > find that most hams don't have a specific purpose in mind when they select > an antenna, they just want a "good antenna" but an antenna that's good for > one purpose may be crap for another. If you know what you're trying to do, > you can look at it through the lens of your purpose and actually get > something that suits your needs. > > I didn't see your answers to Rick Hiller's questions, but they are very > important to understanding what antenna you should get. What kind of > operating do you expect to do? Contesting? Nets? DXing? "Rag Chew and > the usual BS"? What? Is there a particular direction you want to send a > signal? What kind of space do you have for an antenna? Do you have any > objection to laying out radials on the ground? What's your budget? How > much work are you willing to do to make the antenna happen? Do you have an > HOA CC&R that you have to abide by? > > I was pretty happy with the dipoles I used to have back in Ohio. My 20m > dipole was fed with the same line as my 40m dipole and hung underneath it, > looking kind of like an archery bow. A 20m dipole is only about 35 feet > long and only has to be about 15 feet off the ground to radiate like people > think a dipole radiates and I can put two of them at right angles in the > back yard of my 1/6 of an acre lot, one N-S and one E-W. To put them up, I > would tie one end of each to an eye screw in the soffit of my house and the > other end to a 15 foot mast along the back fence. A couple of feed lines > and a coax switch in the shack (or remote antenna switch, if you wanted to > get fancy) plus baluns, if you feel like, and I could go world wide no > matter where they are. You're looking at a couple hundred dollars for that > set up, assuming you buy baluns and the coax switch. Maybe more if you put > in tensioners so the wire doesn't snap in a strong wind. You can use the > wire itself as the structural element, or you can use the twine to support > the copper. If you use the wire to support itself, get hard drawn copper > so that it doesn't stretch. As much. > > Alternately, you could look into the TH-11DX at 100 feet that I mentioned > before. You should be able to get all that for $10,000, I'd guess, > assuming your lot is big enough for a 100 foot tower and the county > engineer approves your plans and permits. I know of at least one HOA where > that might fly, but unless you live near 249 and Louetta, you probably > don't live there. > > On the other extreme, you could buy a metal Slinky(tm) and an antenna > tuner with a single wire output and use that. My late friend Steve worked > the world on 150 watts and a slinky in his shack until he upgraded. That's > what? $10 for a slinky and I can loan you a tuner I'm not using any more. > > My current antenna, which I am not really happy with, is a trap dipole in > the attic. I'm mostly unhappy because picks up every little bit of > electronic noise generated in the house, but there are other reasons, not > having to do with the construction technique. Large parts of every band > are completely unusable and there is a high noise floor on all of them. I > made the traps from coax and PVC fittings, based on an article I read in > QST. This antenna used to work notably better than it does, I suspect > because the HVAC guys damaged it when they replaced my unit this summer, > but it really never worked very well, especially for receiving. I picked > up the book *Receiving Antennas for the Radio Amateur* but I haven't put > any of the ideas in it into practice, even though I have some ferrite rods > specifically for that purpose. Eventually, I will have to chase down the > noise, but during the 10m contest a few years ago, I found that just > putting a vertical antenna outside reduced the noise dramatically while the > signal levels were unchanged, so I'm going to change to an exterior antenna > first. > > My current plan for that exterior antenna calls for winding 1888 inches > (157 feet or so) of 20-gauge magnet wire around five foot lengths of 2-inch > PVC. It won't resonate anywhere, not intentionally anyway, so I'm going to > feed it through a remote antenna tuner and lay out a bunch of radials made > of 26-gauge cross-connect wire, a spool of which I happen to have. I don't > know how many radials I'll lay out, but the idea is to lay them out such > that the ends are about a foot apart. I hope it will cover all of the HF > bands, but I'm not even going to try to analyze it. If I can get it to > work on 160 and 80 and perhaps 40, but have problems with one or more of > the higher bands, I might just buy a second antenna for those higher > bands. I kind of have vague plans of making two of them and using a phaser > to make it a directional phased array, but every time I start thinking > about it, I lie down until the feeling passes. If it doesn't work on some > band (probably because it is accidentally resonant on that band--it's > possible to end feed a resonant half-wave dipole, but the techniques to do > that are specialized) then I may ignore it or I might try something to fix > it. A capacitance hat or something. Who knows? > > I live in an HOA where the operative phrase is "seen from the street" and > I can put up anything I want as long as you can't see it when parked in > front of the house and as long as the neighbors don't complain. Wire > antennas are such an odd thing that, in my experience, the management > company doesn't have a clue that they should complain about them if they > see them, but a column of PVC behind the house won't even be seen. Just > don't hang laundry from it because clotheslines are expressly forbidden. I > might be able to get away with a "spider beam" at about 20 feet, but that > costs more money than I am willing to spend right now, and besides I'm more > interested in the "Low Bands" than in 6-20m > > There's one opinion, worth what you paid for it. I hope it helps. > > On 12/22/20 2:11 PM, Mark Brantana via BVARC wrote: > > Jonathan > I totally agree with your insight. Still have not found a single objective > review of the antenna. Dave Casper is going to do one. That is why I was > looking to see if anyone here has tried one. Meanwhile, yes, there are > people who don’t know any better, and cognitive dissonance is very real. No > one wants to admit to themselves that they bought into something that was > wrong. I noticed that almost every one of the hundred or so antennas on > eHam got 5-starts. Predictably they also write paragraphs praising their > antennas. Interesting. So I totally agree with your premise. > Mark > N5PRD > > Sent from my iPhone > > On Dec 22, 2020, at 8:53 AM, Jonathan Guthrie via BVARC <[email protected]> > <[email protected]> wrote: > > > You ask why there are lots of reviews from people who love the Isotron > even though you can't find anyone who has used it. I don't know why you > can't find anyone who has used it, but I can explain some (most? all?) of > the good reviews. > > First, some people tend to give five-star reviews for stuff they like, but > not love. I tend to not give five-star reviews for 'seems to work the way > it's supposed to' because that's not outstanding, it's expected, but I am > known to be odd. Second, some people are likely fans of Isotron for other > reasons and they would give a five star review to an such an antenna made > of wet string lying on the ground and disconnected from the feedline. > > The thing is, most people have no real idea how to evaluate an antenna and > definitely don't have the setup for it. The equipment most hams used to > evaluate an antenna is an SWR meter, but an SWR meter, in and of itself, > tells you precisely nothing about how well an antenna is working. The > proper tool to use is a field strength meter, but using one of those for an > HF antenna usually requires more land than a typical ham has access to and > more time and effort than they're likely to want to go to. So, what is > someone to do? > > Well, when I was looking into the "EH Antenna" (don't judge me--I seek the > Holy Grail of antennas just like every ham) I found that typically people > would describe "far off" stations as loud or talk about working stations at > so many km. For a receiving antenna, efficiency is not paramount, so > signal strengths are a misleading measure, and the distances for stations > worked were on the order of 150km, as I recall. I'm not impressed by > working a station 150km away on 40m using a small antenna, but if you're > getting contacts through this sheet metal contraption, you can't say that > it doesn't work. If it's working for you, meaning you're making Q's, then > why not give it a positive review? > > Antenna selection is often a matter of balancing what you want to do > against how much money you have to spend and other restrictions you might > have. There's an old list of "antenna truths" that I saw that began with > "Any antenna is better than no antenna" and for many people, the Isotron is > what they can get an use and it does what they need it to do, so they give > it five stars. > > A good option for 20m? Have you considered a TH-11DX up about 100 feet? > > > On 12/21/20 2:45 PM, Mark Brantana via BVARC wrote: > > Thanks to everyone for the insightful comments. I will put the light bulb > antenna on my list. Could an LED work? It should consume less power. > > How come, though, there are so many comments from those who have no > experience with the isotonic antenna, yet eHam is loaded with reviews from > people who love them? Rick makes a good technical point I need to consider, > but don’t understand why wHam has 78 reviews in the past 180 days give a > 5-star average rating for the antenna, and 3.9-star average overall. I get > that there have been disappointing novel antennas in the past. Anyone > remember the can field antenna? > > I am looking for a good option for 20 m and have the coax run and waiting > for the right selection. Open to ideas. > > Mark N5PRD > > Sent from my iPhone > > On Dec 21, 2020, at 10:39 AM, Jonathan Guthrie via BVARC <[email protected]> > <[email protected]> wrote: > > > I have one I got from K5LDD. It's for 80 meters, it comes with no > instructions and some parts may be missing. You want it? > > It should work reasonable well as a radiator, physically small antennas > have been used by many people with great success, but its feedpoint > impedance is going to vary rapidly with frequency and that means it's going > to be fiddly to use. At my age, I dislike fiddly. > > On 12/21/20 9:12 AM, Mark Brantana via BVARC wrote: > > Thank you, Rick. > > Saw one on Dave Casler’s blog last night. He is planning to test it out. > They are said to be good on one band only. Have been a try around 30 years. > I saw a surprising number of 5 star reviews. Has anyone here tried one? > Could just come down to cognitive dissonance on their part. > > Mark > N5PRD > > Sent from my iPhone > > On Dec 21, 2020, at 6:25 AM, Rick Hiller via BVARC <[email protected]> > <[email protected]> wrote: > > Very high Q. Finicky. Poor radiator. > > Sent from my i-Thingamajig > > On Dec 21, 2020, at 12:14 AM, Michael Monsour via BVARC <[email protected]> > wrote: > > You might have the same luck using a light bulb for an antenna-at least it > will be cheaper > > On Sun, Dec 20, 2020 at 10:32 PM Mark Brantana via BVARC <[email protected]> > wrote: > >> Anyone have any experience with an Isotron antenna? >> >> Mark >> N5PRD >> >> ________________________________________________ >> Brazos Valley Amateur Radio Club >> >> BVARC mailing list >> [email protected] >> http://mail.bvarc.org/mailman/listinfo/bvarc_bvarc.org >> > ________________________________________________ > Brazos Valley Amateur Radio Club > > BVARC mailing list > [email protected] > http://mail.bvarc.org/mailman/listinfo/bvarc_bvarc.org > > ________________________________________________ > Brazos Valley Amateur Radio Club > > BVARC mailing list > [email protected] > http://mail.bvarc.org/mailman/listinfo/bvarc_bvarc.org > > > ________________________________________________ > Brazos Valley Amateur Radio Club > > BVARC mailing > [email protected]http://mail.bvarc.org/mailman/listinfo/bvarc_bvarc.org > > > -- > Jonathan Guthrie > ARS KA8KPN > > ________________________________________________ > Brazos Valley Amateur Radio Club > > BVARC mailing list > [email protected] > http://mail.bvarc.org/mailman/listinfo/bvarc_bvarc.org > > > ________________________________________________ > Brazos Valley Amateur Radio Club > > BVARC mailing > [email protected]http://mail.bvarc.org/mailman/listinfo/bvarc_bvarc.org > > > -- > Jonathan Guthrie > ARS KA8KPN > > ________________________________________________ > Brazos Valley Amateur Radio Club > > BVARC mailing list > [email protected] > http://mail.bvarc.org/mailman/listinfo/bvarc_bvarc.org > > > ________________________________________________ > Brazos Valley Amateur Radio Club > > BVARC mailing > [email protected]http://mail.bvarc.org/mailman/listinfo/bvarc_bvarc.org > > > -- > Jonathan Guthrie > ARS KA8KPN > > ________________________________________________ > Brazos Valley Amateur Radio Club > > BVARC mailing list > [email protected] > http://mail.bvarc.org/mailman/listinfo/bvarc_bvarc.org > -- Rick Hiller *e-mail: [email protected] <[email protected]>* *Cell: 832-474-3713* *Physical: 9031 Troulon Drive* * Houston, TX 77036*
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