Jonathan Wow. I am going to have to read this a few more times. Great food for thought. I will write more of my goals later, once I have access to a proper keyboard. Thank you for the details. Mark N5PRD
Sent from my iPhone > On Dec 22, 2020, at 10:35 PM, Rick Hiller via BVARC <[email protected]> wrote: > > > 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]> >>>> 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]> 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]> >>>>>>>> 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 list >>>>>>> [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 list >>>>> [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 list >>> [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] > Cell: 832-474-3713 > Physical: 9031 Troulon Drive > Houston, TX 77036 > ________________________________________________ > Brazos Valley Amateur Radio Club > > BVARC mailing list > [email protected] > http://mail.bvarc.org/mailman/listinfo/bvarc_bvarc.org
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