Aug 27, 2009 the theory behind the eh antenna is total nonsense, as is the theory behind the isotron. The following is from direct measurements and trials i have conducted. Dec 17, 2020 isotron antennas, designed and manufactured by the bilal company, employ a unique new embodiment of a fullsize harmonic antenna which permits the radio amateur who has limited space to get on the air from an apartment, condominium, mobile home, or other spacelimited environments, there are no compromises in matching or tuning isotron antennas to your transmitter. Nov 17, 2008 isotron 2040 m this is the isotron for 20m i use. Somewhere on the isotron website, i believe they make the claim that it is a very quiet receive antenna that can be rotated to null out local noise. Share your videos with friends, family, and the world.
I have used the isotron 4020 for about three years. Most of the tomes used by the last generation of am consulting engineers date back to the 1940s and are no longer in print. To combine pdf files into a single pdf document is easier than it looks. Represents the overall geomagnetic condition of the ionosphere ap if averaged from the kpindex an average of the eight 3hour kindices a referring to amplitude over a given 24 hour period, ranging linearly typically from 1100 but theoretically up to 400. It consists of a coil placed between two angled sheet metal plates.
Gain of the antenna is best achieved by focusing the antenna in certain direction. Antenna should be mounted as high as possible for best performance antennas are ups shippable. Indoor stealth antennas indoor antennas may work very poorly if your home has aluminum siding, a metal roof, steel construction, or foillined insulation. Shipping charges, import taxes, customs duties or other fees are not included in the purchase price and are your responsibility. Isotron is the trade name for a shortwave antenna marketed by bilal co. It is physically short as compared to a dipole antenna for a given frequency. Aug 20, 2016 antenna restrictions isotron antennas are the solution. The first antenna that i built was a 144mhz ringbase antenna designed by f c judd g2bcx and published in practical wireless back in september 1982. Pdf is a hugely popular format for documents simply because it is independent of the hardware or application used to create that file. Depending on the type of scanner you have, you might only be able to scan one page of a document at a time. I used secondhand, coaxfed 20 and 40meter bilal isotron antennas. Jan 10, 2021 antenna restrictions isotron antennas are the solution. The isotron claims the surface area makes a large radiator, but anyone with common sense knows that is untrue. Multiband operation on one feedline with backtoback mounting and no loss of performance.
Ingenuity compensated for a limited budget in the golden age of radio and itll do. In simple terms, we designed the isotrons into a three dimensional package. Searching for a specific type of document on the internet is sometimes like looking for a needle in a haystack. When an isotron antenna was lab tested at 400w, it reportedly smoked and caught on fire. Bilal has been manufacturing the line of isotron antennas for 22 years and makes.
Actual shipping cost will be determined at the time of the. Am broadcast band antennas other frequencies up to 60 mhz available. If your scanner saves files as pdf portbale document format files, the potential exists to merge the individual files into one doc. Amatuer ham radio antennas also great for limited spaces. This means it can be viewed across multiple devices, regardless of the underlying operating system. You can use the tools in paint to add something to a different document. The isotron antenna represents an interesting antenna design and build techniques for an compact transmitting and receiving antenna to be used in small spaces and locations where there are.
Bilal company isotron antennas for over 30 years document preparation. The antenna has not required any futher maintance after assembly. In general you will probably find they are 1520db down from a dipole in signal strength. Manual 80 antennas mounting accessories amateur ham radio antennas contact isotron antennas parts and harnesses isotron, small antenna, lowprofile antenna.
Solve virtually any restricted space problem 40 meter isotron only 22 inches x 16 inches x 15 inches easy, quick, and simple installation. By michelle rae uy 24 january 2020 knowing how to combine pdf files isnt reserved. Compact and portable antennas at a glance alpha delta outreachoutpost bilal isotron 40 force 12 zr3 mfj1788 traffie hex beam ii band or frequency range 16010 meters 40 meters 20, 15 and 10 meters 7. Im leaning towards an aea or mfj isoloop for 1030 and the isotron for 4080. Doclive free unlimited document files search and download. Dec 10, 2020 antenna restrictions isotron antennas are the solution. Needs minimal 14 coax feedline to work and a chocke at 14 wave from the antenna. Ive got some questions and would like comments on either or both of these unique antenna designs. In those days, qst required manufacturers who wanted to advertise a product in qst to send a sample for evaluation in the arrl lab. It may behave similar to a receive loop, with nulls broadside to the faces of the loop. If, you have a balcony, inside house, or basement dont purchase the isotron antenna s. Discussion in cb antennas started by smilex2692002, jan 5, 2014. Its most certainly not the snake oil contained in the isotron antenna thats making the contact happen. I paid for a pro membership specifically to enable this feature.
The unit is mounted on 20 ft steel 2in pole and a 8 foot copper ground rod under the pole. Tunes and performs without radials or antenna tuners. Antenna restrictions isotron antennas are the solution. I mounted them on the balcony before operating and took them down when i was done.
Stealth antennas the columbia amateur radio club presents. Although no longer made by aea, mfj has picked up the slack here. This antenna works great running about 100 watts while working stations in the usa, mexico, south america and canada. David lowrance al5x for the betterment of amateur radio, this document is public domain. Jun 16, 2009 the isotron is a lossy tuned circuit that radiates. My rst using a 5band vertical was 59 while wb3gbfs rst, using an isotron 40meter antenna, was 520 db over 9. Lightning arrestor inline will further improve the sn ratio. I can picture them all on one tower with no wires, control cables or antenna rotors. I found that for the cost and ease in mounting the isotron is an efficient antenna. However, unless you have a very high tree and cant hang a 40m or 80m dipole. Sep 09, 2015 the isotron 201510 combination antenna system requires only 1 feed lines and one metal mast. Isotron iso11 11m cb radio antenna dipole performance.
If you are hearing a good signal from an isotron, then you may be doing all the heavy lifting to give that other station a good signal report. Ralph had promised to send me the lat the tv mast with the help of my xyl who see if the isotron was really an antenna. Easy, quick, and simple installation tunes and performs without radials or antenna tuners handles up to watts pep depending on mode and version. Pdf file or convert a pdf file to docx, jpg, or other file format. A normal wideband two element reflectordriver yagi is about 5. I still have it in my shed and it still works perfectly. A 32mm diameter gray pvc tube, 2mm coppercoated sheathed singleconductor wire 3mm with the sheath, two pvc sleeves for 32mm tube, two metal disks hs hard disks for example cm diameter. Recommend instead, wire, yagi, dipole, horizontal, vertical antenna s. This means you will be hearing only the strongest of signals on the band. The instruction manual from bilal is sort of basic. I have the 80m, 40m and 20m versions of the isoltron antennas.
One antenna that has always caught my eye has been the isotron. Solve virtually any restricted space problem 40 meter isotron only 22 inches x 16 inches x 15 inches. Location and setup is the critical factor in how these antennas perform. I cant and wont recommend isotron antenna sto any person. Hf antennas especially stealth models for those in an hoa.
Prior to the gable end roof mounting i did testing and tuning. One of the fun things about computers is playing with programs like paint. A pdf file is a portable document format file, developed by adobe systems. Solves virtually any restricted space problem for example, a 40 meter isotron measures only 22 inches x 16 inches x 15 inches. An oversized pdf file can be hard to send through email and may not upload onto certain file managers. This article explains what pdfs are, how to open one, all the different ways.
I own 10, 20, 40 and 80 meter isotrons and have just ordered the 6 meter version. I have build it by following the instructions on the homepage of f5swn, but for 80m band and with copper plates. One antenna that has always caught my eye has been the isotron as sold by the bilal company in america. Isotron am broadcast antennas transmission equipment. Most electronic documents such as software manuals, hardware manuals and ebooks come in the pdf portable document format file format. Making a pdf file of a logo is surprisingly easy and is essential for most web designers. Antenna should be mounted on a metal mast with a maximum size of 1. The isotron am antennas are the perfect am broadcast antenna for all broadcast band am transmitters from 300 to watts. Antennas mounting accessories amateur ham radio antennas contact isotron antennas parts and harnesses isotron, small antenna. While they took snapshots of the isotron site all the way back to 2003, the isotron site is strangely silent on the older, shorter version of the isotron 160. The 40meter isotron instruction manual is a small, 18 page manual put. Wire antennas can be run near the peak of the roof inside the attic, bent in odd shapes to match the space available. If the radiation is focused in certain angle, then eirp increases along with the antenna gain.
Page 3 compensation for variation in location the antenna toground capacitance of your isotron antenna depends on its location with respect to. The feedpoint is what determines how the antenna will match the transmitter and measurements taken at the connector of the antenna. Tuning an isotron 20mtr antenna i have this isotron purchased some time ago to use on 20 meter psk31 but never got around to. Please see individual antenna listings for more details. Tuning an isotron 20mtr antenna now that i have enough gnuradio tools to measure reflection coeffecients, sweeping across a range of frequencies collecting magnitue and phase data it should be possible to put them to use for something practical like tuning an antenna. The mast can be groundmounted with guy wires, mounted to a wooden pole, or attached to a tower leg. May 24, 2019 you can make contacts with isotron antennas. An isotron antenna generally should not have any type of choke balun at the feedpoint, even though the feedline carries some commonmode current and radiates along with the antenna. Once youve done it, youll be able to easily send the logos you create to clients, make them available for download, or attach them to emails in a fo. On 30m or 20m this combination of height and somewhat lower loss clearly favors the isotron as it would any reasonably efficient small antenna. Please remember, isotron broadcast antennas are custom made at time of order. Manual 40 antennas mounting accessories amateur ham radio antennas contact isotron antennas parts and harnesses isotron, small antenna, lowprofile antenna. Antenna to ground capacitance affects resonant frequency and feedpoint impedance of your antenna.
Aug 20, 2010 the a index low is good 1 to 6 is best. But if you are looking for a compact, mulitband solution to your antenna situation, consider this amazing option. If your pdf reader is displaying an error instead of opening a pdf file, chances are that the file is c. Amateurs may use any of the material as you choose to, including my photos and all text. So now i am a believer in isotrons, but studying and following the manual is a must. Jul, 2020 2014 dayton hamvention antenna check this great article by g0ksc in.
Bilal isotron antennas radio amateur 101981 amateur. In the apartment i used secondhand, coaxfed 20 and 40meter bilal isotron antennas. The paint program can help you make new image files, but it cannot open document or pdf file. Therefore whether the circuit is on your radio board or hanging as an antenna, all formulas and theories apply. Luckily, there are lots of free and paid tools that can compress a pdf file in just a few easy steps. Both of those antennas, even though they have very different excuses about how the antenna works, are based on nonsense. It is the purpose of this paper to provide the interested reader with a general body of knowledge of am antenna systems. Antenna isotron 152040, f1rfm in reception, i only lost one point on average compared to dipole despite the poor release of the isotron. The isotron is not a substitute for a yagi at a 100, but provides a good alternative for those without a large amount of space to mount a large antenna. The tuning of the isotron is a little tricky sometimes.
I just went to the wayback machine site and a couple of others. When the isotron antenna appeared on the market, the manufacturer tried to advertise the isotron in qst. Ive used two of them, and although they can make contacts, ive had way better success with the mfj super hiq loop antenna which is actually no larger than an isotron but covers several bands and is perfectly resonant on each, and works incredibly well for its size. The gain of such antenna will be 3dbi where 3db is a factor of 2 and i represents factor of isotropic condition. Isotron must be above the roof line or in your yard. At the feedpoint the dipole or isotron am antenna will resonate. Read on to find out just how to combine multiple pdf files on macos and windows 10. A tiny 18 inch 20 meter vertical that operates on the same. I would venture to say that the same is true for those that use the the isotron antenna. They use the coax as an active part of the antenna.
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