Here's how I used these brackets to route and 160 meter full wave loop antenna. to a ground stake, for lightning protection. Put a connector on one end of about a Here is how the top of each corner post was I found a 60 meter resonance for this 160 loop (third harmonic) and it did not work as well as a low dipole cut for 60 meters. Then another approximately 100 Ft of standard 50 ohm coax brings it into the shack. Both loop and dipole at the same (lower) height lose performance beyond the blue circle, but the loop is still consistently better than the dipole at the high angles. It seems clear from this very basic, but perfectly reasonable, EZNEC simulation a full wave 160 meter loop running in the 80 meter band is a good antenna for DX work, but leaves much to be desired for NVIS even if you lower it towards the ground like you do with a dipole. I was unable to copy the other station since he was lower power, but it was quite a thrill. frequency is maybe more pronounced on 80m, a secondary target Amy(AI6ZU) and I build a magnetic loop antenna for 160 and 80 meter amateur radio. 1) This antenna is over three metres in diameter and weighs around 30 kilograms. I wanted slightly above mid band, to favor 1.885 and 1.945, the common AM frequencies in this area. I do not understand why people study for an exam and learn the formulas for antenna lengths, obtain SWR bridges or antenna analyzers, and still buy pre cut commecial dipoles. It did work for DX, but was lousy for local ragchews beyond There are some caveats you need to consider before constructing this antenna. At swap meets, buy up older ceramic insulators whenever you can. The loop theoretical radiation is 1 to 2 dB better than a dipole of the same height (half an S unit). I now have a linear amp that covers 160. Magnetic loop antenna for 160 - 15 metres. pictures for details. His conclusion is: "Good NVIS gains are available from a broad range of heights starting at 20 feet up to 45 or so feet. A helically wound 80 and 75 meter vertical did quite well over the same ground plane wires. is a minimum SWR point (off the left side of the graph). In Ithaca, I have to run over 200 feet of coax to get the loop away from Use the best stuff and install it ONCE. The surface has deteriorated and eroded, exposing rough interior plastic. Some guy telling you that you oughta have a balun is not an Two days after I posted this, my 160 meter inverted “L” antenna was taken out in a storm. take care of it. Double Extended Zepp Antenna. K9AY 7. The insulators on Long Island are available at Agway or a farm store. Balance does not The formula for this impedance transformation was on your Extra theory test. https://www.dxengineering.com/search/product-line/dx-engineering-rg-11-u-75-ohm-bulk-coaxial-cable. K3ZXL - 160 Meter Receiving Loop Project Dan Schaaf 20 January 2010 _____ For several years, I have been struggling with atmospheric noise on the 160 meter band. Half Delta Loop Antenna. To cut the antenna wire length to resonance we use the formula: Length (in feet) = 1005 divided by frequency (in MHz). Remember that an S unit is about 6 dB, so it is unlikely to show measureable difference in the real world. An early version of … the pictures. Here is the Google Earth graphic with the The purveyors of these antennas have to compete on price, so they often take short cuts. 160 meter full wave loop antenna The antenna is a 10 - 160 meter horizontal loop fed with 450 ohm ladder line all the way into the ham shack to an Palstar AT1500BAL balanced line antenna tuner Trapped dipole for 40-80-160 meters Build a space efficient trapped dipole antenna for 40-80-160 meter bands using RG-58 and PVC pipe by W8NX I use a $13 Wireman #801 CQ dipole center insulator: I use ceramic MFJ 16C06 insulators at each support. a spool of STRANDED #12 or #14 THHN wire at Lowe's for less than $50. 1 1/8" hole separation wire antenna insulators and may be black, gray … Solve Common Mode Noise Issues with Common Mode Chokes For Beverages, Active 8-Cir/4-SQ Arrays, Other RX-Antennas N3RR Solutions, Typical 75 Ohm … I do not address the use of a loop as a multiband affair. YES, I am still building 160/ 80m, 80m and 160m receive loops. EFFECT OF SHORT DIPOLE. band. Full-wave loop antennas can be large at lower frequencies, but they are quieter than dipoles and have more gain broadside to the plane of the loop. Even for NVIS close in work, the ground loss increases as the antenna gets lower to the ground. holding a J-pole for VHF/UHF. Significant amounts of power would break it down if it got damp, and even at QRP the loss would make it unuseable. I feed In the case of commercial multiband fan dipoles, nearly all have separator insulators that are too close spaced. They are electric I did a a choke coil of coax) can actually increase the system problem. This can influence the accuracy of the modeled results. There is a story that some computer analysis of the bumble bee concluded that it was impossible for them to fly. Most all tuners use an inferior voltage balun, and should never be used. As the frequency of minimum SWR approached the QST June 2016 page 45 advocates the case for a dipole; the gist is the VERTICAL loop average height is lower than the identical dipole or inverted V and therefore low angle gain is lower and ground losses higher. As it turns out, building a 160m loop antenna with a total circumference of λ/3, even within the restricted space of a residential yard, is not difficult at all. 160m Capacitance Loaded Vertical Antenna. Another item on this website discussed antennas that amateurs use to operate from confined locations. the loop. Getting the most RF in the air matters. Take them off and throw them away immediately after you take these antennas out of their box. quarter wave of the coax. center fed types like the Carolina Windom are the same stuff. eliminated all that loss that would have resulted from SWR caused by using 50 ohm coax all the way. Use a bare wire to hold the insulator in position on the insulated antenna wire as shown. Based on his data, I decided NOT to install a ground reflector on my 40 meter dipole, mostly due to the extra complexity and difficulty mowing the lawn. Random Length Radiator Wire Antenna. Note that the element is continuous except for a gap at the top across which the variable capacitor is wired. transition to 50 ohm coax. 2) The antenna must be mounted on a suitable post and guyed for stability. Please take this in the spirit in which it is offered: not the grumblings of an old curmudgeon, but the encouragement to "exper"-iment and gain "exper"-ience that gives you the confidence to build your own antennas from high quality available raw materials and learn something useful in the process. By Chris, G0DWV. He also explains the term dBi (gain over a non existent ISOTROPIC antenna that antenna manufactures use to confuse the unwary). The increased resistance in the SWR plot at the low end of the band shows that choice. I have the luxury of enough land to have wire antennas optimized for each band. by 125 feet, on Long Island. A review of the literature on 160 meter antenna designs leads to the usual discussion of dipoles, inverted-L's, T's, V's, loops, deltas, and verticals. You can use a full-wave loop on frequencies higher than design frequency as well (for example, … There is some mythology about NVIS or Near Vertical Incidence antennas. We must subtract 4% of the total full wave length if we are using insulated wire. 40m - 80m - 160m Short Dipole Antenna. I used ceramic MFJ 16C06 insulators in Ithaca. I do not do open wire feeders, for a variety of reasons already discussed on this page. This antenna normally has about a 3 DB gain over a 1/2 wave center fed dipole. The mechanical like erecting a wet spaghetti noodle. Let your antenna down JUST ONCE (if it was up yet), adjust the length, put it (back) up, and you are done. AB0X Roof Loop 2. loading coil would reduce bandwidth and radiated signal. 160m Half-Sloper Antenna… indicated. Delta Loop Antenna. https://en.wikipedia.org/wiki/Quarter-wave_impedance_transformer. I asked him about his success and his … When propagation is extraordinarily good, winter during a sunspot minimum, double hop can occur at longer distances at times. And the balun is lossy, never achieves balance, and balance does not matter anyway. It worked well in it’s only test, and will be reconstructed. design frequency, the minimum SWR also dropped. Due to the short length, this will probably continue as my only 160 meter antenna at this QTH. For a discussion of how this technique works, see: Replace them with MFJ 16C06 insulators or better. If you use the line specified, my length should be close enough to work, if you cut the antenna length properly. Since the antenna is resonant, there is little reactance and no high voltages. Further, a loop in any orientation is inherently broader band width than a dipole. For instance, if you are comparing a beam antenna to a dipole, you must subtract at least 8 dB from a beam rated in dBi. ground wave distance. no @#$% balun! the calculated wavelength because the wave travels slower in the coax than 1.9 MHz Full-Wave Loop Antenna. But W8JI focuses his discussion on VERTICAL plane loops and low angle patterns for DX.

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