eyebolt nuts with two flat washers.The coax is taped to a ten-inch from the tower I used an electric service entrance insulator fastened by I always use 300 ohm tv twinlead that is still being sold at most Radio Shacks in the USat least for now still being sold. On 75 and 80 meters, you should have about a 220 kHz bandwidth. Even up on the hill in Martinez it wasn't bad. The delta loop is 264.5 feet in total length. The next step was a site survey through my garden. The direction of fire is broadside to the antenna. Ham Radio operators review new sites every day since 1998, for potential inclusion in the Directory, and to evaluate the best place to list them. Debugging SM0VPO's spiral loop antenna build. Heinz I and II left the antenna analyzer to me and I was able to keep it quiet. Here I have divided the two long wires again into 2 parts, because I wanted to simulate the intentional sagging of the long wires here. The opposite end of the feed point is approximately 35' AGL. We use cookies to ensure that our website runs as smoothly as possible. The N3FJZ antenna system. If the loop is going to be used as a single-band antenna (meaning that it will provide a feedpoint impedance of around 50 Ohms) then using coax for the feedline will work well. Cebik W4RNL goes into Using a 160 meter full wave loop in that fashion is likely to be counterproductive. know that I built the KL7JR Sloping Vertical Delta Loop and I am having a wire used. Clarification: Thiis was a better all band antenna than the 160 L or the 240 ft dipole. (This includes any inappropriate posts on a topic, as I cannot monitor every topic.) For the sake of completeness, the plots for bands 40, 30, 20 and 10m follow, which already show a clear directional characteristic. is above the horizontal base wire of the antenna. Hamuniverse.com uses Green Geeks Web To my delight, theory (EZNEC calculations) and practice (miniVNA measurements) were not far apart, comparing the above EZNEC diagram for 1 30 MHz with the image below. eHam.net provides recognition and enjoyment to the people who use, contribute, and build the site. cwJM7 20m cwA92 20m SSB5T0 It always handles full legal limit power with no problems. https://hamradiohawaii.wordpress.com. I then repeated the same measurement assuming an input impedance of 200 ohms, hoping that the upper band SWR values would improve, i.a. right.For the feedpoint connection I used a 1-1/2" PVC pipe T I wish I had tried this antenna sooner in my ham hobby years. /* Ad banner 160 x 600 */ For example why not feed with 450ohm line, then a 9:1 balun into coax? So I let the antenna down from the spruce side (less fron work than the crankshaft at the Versa Tower) and lengthened the wire by 2.70. Say you don't have the room for a full wave antenna then . Full wave HF loop antennas are ideal NVIS (near vertical incident skywave) antennas for local, state, and regional communications. Use a TV coax and balun for a poor-man's OCFD? found to be so appealing about this antenna was that it was fairly To build this antenna you need a lot that is at least 100 feet across. SWR and impedances in the frequency range 1 31 MHz. The also exhibit gain on harmonic bands. Site design / logo 2023 Stack Exchange Inc; user contributions licensed under CC BY-SA. A Hawaii-based Amateur Radio Antenna Blog focusing on the theory, design, and use of homemade antennas. Conditions have been average lately so it has to get better as the propagation improves. With the SWR button you can now display the resonances of the antenna structure over any frequency range, as shown below. Antenna covers all bands 80-10 meters + 30, 17, 12 meter WARC Bands This antenna works as a Full Wave Loop on 80 Meters and also works as a 2 wavelength open loop or Bi-Square on the 40 Meter band 80m 2 element Yagi antenna 2 elements short boom yagi for 80 meters Receiving antenna for low bands K9AY loop antenna installed at PA6Z Contest group. google_ad_client = "ca-pub-9377297764300878"; Well, some.. depending on your choice of It may even have loaded on 160 meters but I forgot to try. Antenna for Condo Backyard-Stealth. Jim you are absolutely correct. A little wood, some wire and a handful of components can make a directional antenna for indoor use where outdoor antennas are not permitted. This is a little long for 80, 17 and 12 meters, but a little short for 40 and 30 meters and just right for 20, 15 and 10 meters. https://bigislandarrlnews.com. Then I cranked the mast at nominal height about 16 m high, and performed a new measurement. percentof them being with stations outside North America *(about 10% The 40m band looks similar, but with a worse but acceptable SWR without impedance matching: Below are the EZNEC calculated directivity diagrams for all shortwave bands. This antenna is resonant at 3.650 MHz-~-~~-~~~-~~-~-Please watch: "Minelab Manticore fir. Are there any canonical examples of the Prime Directive being broken that aren't shown on screen? Anyone do the same Delta but horizontal? It was an 80 meter delta loop, apex up, with the top attached to the top of a 60 foot tower. According to Rich, this antenna is resonant at 3.650 MHz. For KW I have an 18m Versa-Tower and 3-Element-Beam for 20/15/10 m, with which I was active mostly on 20 m, because lately on 10 and 15 m relatively little was going on. It worked just fine 80 10. Often times on 80m far! 5x1 quality "both ways".For those doing the math, call the remaining 5 But since my main interest is in 80 / 40m operation, I have then made me to connect the cable at the feed point without impedance matching. Remember to add at least 8 feet to dimension "A". 43-45. With EZNEC I had calculated the values directly at the feed-in point of the antenna. It outperforms dipoles and OCF antennas. All stainless steel, 600 Watt, with proper strain relief. Should I re-do this cinched PEX connection? Interpreting non-statistically significant results: Do we have "no evidence" or "insufficient evidence" to reject the null? It would load on 160 but did not xmit really work well but did receive very well on that band, very low noise receive antenna. galvanized water pipe. The impedance at the loop resonant frequency is approximately 100 ohms but will very slightly on harmonics. 7 Delta Loops for 7 MHz. This configuration is best suited for working long haul DX. Hams!About HamuniverseAntenna DesignAntenna Safety! Trying to avoid buying a tuner. it has out-performed my OCF dipole, dipole and inverted L, when ALL bands from 10-160 are taken into account. Why not equip your bicycle for 2 meter/70 cm mobile operation? The 80m delta loop is a field day team's secret weapon to run 80 and 40m frequencies. The diagram nicely shows the resonances at 3.6 MHz and their multiples. pileups on the first or second call. google_ad_height = 600; Noise Suppression up to 38 dB, Receiver Impedance/Isolation Transformers, Broad Band Terminated Dipoles (BBTD, T2FD). in QST over the years on loop antennas. If you can't see the video, please insert this title URL into your browser search box: https://www.youtube.com/watch?v=aeNHIQ_j4Dk This well-produced and richly illustrated tutorial on the classic G5RV HF Dipole Antenna was presented to the Brandon Amateur Radio Society in Brandon, Florida in 2017 by Bernie Huth (W4BGH). My Versa Tower is firmly screwed to the garage wall, I can crank it down to the height of about 7-8 m. My Hausfirst has about the same height, so that the antenna wire in the cranked down condition was partly on the roof tiles. This added height will be how high the base of the antenna will be above ground. .