Counterpoise lengths

3. Although many antenna experts recommend that the tuned counterpoise be lengthened by approximately 5%, I decided to keep both vertical and counterpoise elements the same lengths. 2 MHz 18. It can be used when the radio is on the table top or even if the radio is used like an HF HT. Three 57′ long lengths of coax tied together at a common ring terminal. It is designed as a highly portable wire antenna, easily set up as an inverted V, horizontal, sloper, or in the case of higher frequencies, a vertical radiator. If you have to be further away, you want a 1/2 wavelength of wire to the ground. Some elevated counterpoise wires running along the fence under the wire helped to improve radiation efficiency. Jan 24, 2019 · The random wire antenna is probably one of the least expensive, easiest and cheapest HF antennas to use if you have a tuner and you want to get the "most" out of a length of "random" wire without having to pull out that calculator, doing the math, getting the center insulator built or bought, running the feedline, and all the rest that goes with putting up a more elaborate antenna. The lengths calculated from this should only be considered as an approximate value – it is best to cut the wire slightly longer than this and then twist the end of the wire back on itself to give the best match. 5-Inch Dual Band SMA-F Antenna for Baofeng Radios. It does have the advantage of multiple cut lengths, but is only one physical wire if used as a single wire counterpoise. 0Mhz - 17ft 14Mhz - 6. Isolation Ring – insulates Counterpoise Wire (b) from Tent Peg (e) and ground. These antennas can be mounted horizontally, vertically or as a sloper. The counterpoise is usually a ground plane on the circuit board. Common lengths are 44' 53' etc. 5ft 28Mhz - none; Tuning Unit The first kind is deliberately non-resonant, uses a 9:1 unun and requires a tuner. And took pictures. 5 feet of wire. * * * Related Products. Designed as a 20m antenna. Rugged weather-resistant 50-Ohm matching network. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed. Finale. 278 e, respectively. Again, more is better and will increase efficiency. Unfortunately, we didn't keep in touch with the owners, so we don't know how well the counterpoise worked nor whether there were any long term bonding problems. Be sure not to reverse these wires. In radio and telecommunications a dipole antenna or doublet is the simplest and most widely used class of antenna. you experience RF in the shack or other problems, alter the counterpoise or add a different length of wire. Used at MF and HF to provide an RF ground for an antenna. There is a wide range of counterpoise lengths for which a low SWR can be achieved for each band. (3/2 λ) doublet with 31 (1/4 λ) ft of ladder line, then fed with coax. SWR will vary based on topography, wire orientation and use of ground or counterpoise. This may be This site gives a list of random wire lengths to avoid, and a table of "good" lengths, but is silent on the matter of counterpoises. This 200 watt Unun also operates "stand alone" meaning that it does not necessarily require a tuner for use on certain antenna. At first glance, a vertical looks like little more than a metal pole jutting skyward. It has been shown that different lengths or removal of the counterpoise altogether, can improve performance, as described in RadCom, August 1996 by G3LCK. The coupler can be adjusted to compensate for any reactance that may be present due to other lengths but it is around this length where the whole antenna system is the Mar 22, 2012 · The counterpoise is nothing more than a wire that can also be used as a guy line if you insulate the ground side — it is the “other half” of the dipole. 5' turns in from VTEE side turns in from the whip end VersaTee at chest height. It is also possible to de ne a counterpoise correction for trimers and larger clusters. The antenna is an AS-1887A. If it was a specific length, it would be called a resonant antenna radial. This is an End-Fed Half-Wave (EFHW*) antenna for 80/40/30/20/17/15/12 and 10m bands. For best results, use the longest wire Wire Length Feet 1. The equilibrium bond lengths r{sub e}, and harmonic frequencies w{sub e} are also calculated for a few selected molecules. 9 of a full wave length). How long is the counterpoise? The overall length including the "pigtail" that is attached to the antenna bracket is the appropriate length for the frequency based on Bonnie KQ6XA's research. Figure from Laport [14]. The best length for the ground plane wire is less than 1/4 wave. The counterpoise acts like one of the poles in a dipole antenna while the monopole antenna acts as the other pole. RG58 coax for a feedline. Simply hang the far end from a tree limb–the coax is at the bottom. Jan 20, 2013 · The counterpoise wires are cut 5-10% longer than the antenna wire, and are used to support the antenna. I also use it as a travel antenna. 11 Oct 2014 If this is done then the current into any length of "counterpoise" is minimal except when those lengths approach a half wave length. Ground plane lengths given for lowest frequency in each band. That is all for now, feel free to contact me with questions, or if you're on Facebook, check out my Facebook ham radio help page. I used Coaxial Lightning Arrestors to achieve this. The random wire should be a quarter-wave length or less at the operating frequency. 5' 7. 05 wavelength "counterpoise" length is what I also determined empirically as to being the ideal length for the counterpoise. 38-44, 55, 60, 68-73 Feet. amateur radio bands circa 1936. 278 and 0. There is a minimum length though, and that's probably around 8 - 10 feet. in odd multiple lengths of 1/8 wavelength on the lowest operating frequency. Jack, VE3EED, used center frequencies of the bands described in the article above, and I thought it would be nice to use band edges. The antenna displays a low feed impedance, which allow you to feed it directly with 50-ohm coax cable. 05 or . When setting up this antenna, the build quality did feel a little on the cheap side. The counterpoise length in feet = 180 / F (MHz). These changes further improved the SWR curve, and after a few more iterations of counterpoise wire lengths, I was able to get something close to the SWR curve as shown by G7FEK, except on 21MHz. The KISS SSB Counterpoise - Revealed ( with Pics ) - Cruisers & Sailing Forums Our patent pending system has allowed us to get all the radial lengths (some in excess of 60 feet) and a few loading coils in a self-contained ten foot long housing. This is a great antenna for portable operations and will work best with the counterpoise lengths suggested. 44 - Counterpoise Longwire. 1 MHz 21. Hang it up in a hotel window or string it up in The simulating experiments were performed to analyze influences of the length of the counterpoise wire on the impulse characteristics. 10m counterpoise produced excessive impedance at the end fed transformer secondary, which the transformer was not designed to match. That counterpoise will benefit your transmitions and reception. Dipole Antenna Calculator. A quarter-wavelength antenna is easy and inexpensive to build and can be an effective antenna with a low angle of radiation (that is, power is radiated out, not up). If the current is  4 Aug 2015 The problem of an electrically short antenna is familiar to anyone operating in medium-wave bands. Fig. When on the ground or slightly buried the actual lengths will be substantially shorter than when "in the clear" usually they end up approximately 1/2 the length of a free space radial/counterpoise. 3 feet 20 meters 17. 32, "An Unorthodox Antenna") is an 84' long end fed and a 17' long counterpoise (6. "An Unorthodox Antenna"): an 84' long end fed and a 17' long counterpoise (6. Here a plainchant melody, or “principal voice” (vox principalis), is combined with another part, “organal voice” (vox organalis), singing the same melody in parallel motion a perfect fourth or fifth below (e. It can be hung as a sloper, an inverted L, hung in a straight line, zigzagged, vertical, horizontal, etc. Optional mounting holes for paracord, mini bungies. The counterpoise wire does not have to be similar in length to the main radiator wire and just a short wire is all that is needed, about 0. This is the antenna I use the most and it works great. When we look at how the word has been commonly used, we see general use and dictionary We look at the magnitude of the impedance of an EFHW “antenna” for short counterpoise lengths. This helps to show how a radial system affects radiating efficiencies of antennas of different lengths. The best way to resolve this is to fit a choke, such as eight turns of RG58 through an FT240-43 ferrite toroid about a 10 feet or so from the matching unit. Some suggest a counterpoise of . ideally the counterpoise element length should be a few percent longer than the vertical, but can be the same length. The first half goes positive, the second half goes negative. This antenna requires at least 25′ of coax feed line with no chokes. If you are near a wire fence, connect the ground to it. 1 MHz 10. Run the counterpoise in any direction you want, but make sure it is at least 5% longer than the antenna wire. This Icom endorsed principle is the one and only complete counterpoise system. All antenna lengths in the information below are in feet and are the results based on the standard formula of 468 / FMhz = total length in feet. 47 - Vertical Sleeve Antenna for 10m. There is one dipole arm threaded into the top of the Tee. The vertical section should be as high as possible, with the remainder of the antenna run horizontally to a support, such as a tree or a mast. Verticals are commonly installed at ground level, although you can also place a vertical on the roof of a building. Take care and Aug 12, 2016 · The counterpoise is 16-ft long and the main element and counterpoise are suspended as a dipole. Dec 11, 2016 · The counterpoise connects to the ground side of the unun and lays on the ground parallel to the antenna wire, just as in version 2. Any counterpoise should be at least 1 foot above ground running away from or perpendicular to the antenna wire. d. The most unambiguous way to de ne this procedure is to use the trimer basis set for the counterpoise correction. If possible run the counterpoise above ground away from or perpendicular to the  Radials of any length are better than none, but ideally a quarter-wavelength. It has been shown that different lengths or removal of the counterpoise altogether , can improve performance, as described in RadCom, August 1996 by G3LCK. These are connected to the shield of the feedline. So to my question: if I were to make a W3EDP-like wire antenna, but not 25. 59++ on FM 10 meter repeater in NY. Jun 27, 2012 · The cold side of the unun is connected to a 4-wire counterpoise that has lengths corresponding roughly to 1/4 wave on 40, 20 and 10 meters. Your feed line is essentially the counterpoise, so a separate one is not needed. The best counterpoise is 1/4-wavelength at the lowest frequency you intend to use. Everything is well grounded in my shack. 63 m) H or V 4 85 inches (2. Apr 21, 2018 · Antenna Counterpoise, misconceptions and mistakes with building a rat tail - Duration: 16:52. Description. 20-30 feet but NOT resonant. With a proper counterpoise and antenna 40 to 150 watts should be able to transmit 1,000's of miles easily at the right time of the day. For 14-gauge wire I use bamboo skewers that are about 3/16” diameter. A standard earth connector tab was used to make the connection. UPDATE: I finally got the time to play with this sytem some more, and found that I can use a 50' wire and 50' counterpoise and it will tune to a good match on all bands 10 thru 80 meters. If you are only interested in operating 40 through 10 meters, you can try 36, 44, or 49 feet. Insulate the ends And of course, a counterpoise with various lengths. The dipole is any one of a class of antennas producing a radiation pattern approximating that of an elementary electric dipole with a radiating structure supporting a line current so energized that the current has only one node at each end. sized radial lengths (tuned radials) are critical to the antenna's proper operation. Insulate the ends of each radial from other metal objects. I tuned the coupler to resonance into a resistor (in my case 3. So, the counterpoise wire was cut to a length of 16. counterpoise and antenna tuner. Surprisingly, if the lead is an electrical quarter wave, it would work MUCH better if it were not connected at all at the far end, and used as a counterpoise. Its a compromise but it does work if the bands are in good shape. I made quite a few contacts on 40m from the Dayton Hamvention operating portable out by the fleamarket area . 5 feet 15 meters 11. b. , Electronic spectra and electronic structure of polyatomic molecules,Van Nostrand,New York, 1966 : 1974Hel/Hel(II/6) The LDG Electronics RU-9:1 Unun was designed to allow easy interface of random length vertical and end fed antennas to the LDG line of Automatic Antenna Tuners. 20-40 feet but NOT resonant. I cut the tip off the tape measure and attached a spade lug to facilitate connection to the balun. A similar process was undertaken for the counterpoise. Some say that you can use a 4 meter long counterpoise down to the 40M band, but I don’t know. 8 MHz 3. 2m tall wooden fence 4 radials stapled to top of fence Ground Spike Elevated antenna Copper rod . ,  I would like to briefly take up Booth's sample metaphor which he dis- cusses at length and from various viewpoints (p. This saves a lot of work and makes the counterpoise easier to hide. I have read that the correct length for a counterpoise would be 25% of the wavelength of the lowest frequency to be used, in effect to ‘mirror’ the 1/4 wave antenna on the tripod to create the other half of the antenna. Support my that a short counterpoise is a good idea; Interestingly a link coupled tuning system appears to be preferred by W8JI and AA5TB. The counterpoise can be a ground system like radials instead of a single counterpoise. Length of counterpoise should be a minimum of 30-40 feet but not the same length of the antenna wire. More radials will give a stronger current reading. :-) > > Message: 26 > Date: Sun, 29 Jan 2017 02:38:20 +0100 > From: "Emory Schley" <[hidden email]> > To: Elecraft <[hidden email]> > Subject: [Elecraft squib reference DOI; 1966Herzberg: Herzberg, G. I tested all three configurations and found that #3, no ground or counterpoise, gave far and away the best results for me - SWR 1. 17m. Extended Double Zepp – Longer than a dipole (5/8 wave or longer). Bands . Sep 24, 2018 · Return loss of J-Pole on varying lengths of mast with and without the stub. Ham Radio HF/VHF Antenna Lengths Chart. That length is typically at least what it takes to get from the antenna to the radio so it's a sort of an "ain't no thang" thing. The measurements below are for building a simple Dipole Antenna. It's great for fine-tuning counterpoise lengths: I just cut them a bit short (as the directions indicate) then tune the counterpoise to maximum RF current. Quick Tilt Ground Mount Challenger Counterpoise Assembly $ 39. This calculator is designed to give the vertical length (height) of a particular antenna, for the frequency and wavelength chosen. Here are some excerpts from the Counterpoise_Radial_Length file on the HFPack yahoo group: Counterpoise wire touching Earth This is a great antenna for portable operations and will work best with the counterpoise lengths suggested. The atom charges of C and H are −0. Shorter length counterpoise wires can be used if operation is confined to 40m or higher. (Yes, it's shorter than a quarter wave. Think of a "sine wave" 12 cm long. One solution is the counterpoise ground  So the use in a quarter wave ground plane antenna of a system of pairs of opposing radial conductors carrying equal currents in opposite directions such that  The coupler can be adjusted to The end fed half wave antenna can be operated with a small counterpoise, and However the physical length is slightly different  11 Sep 2017 The Counterpoise keyword requires an integer value specifying the number of fragments or monomers in the molecular structure: e. I decided to just use a few jumper wires chained together to create a counterpoise, with a total length of about four feet. 47 feet (5. Again, I haven’t tried this one. However, the main thing I found is that the feedline must be dressed a certain way. Make this from a piece (19. That's because there are no specific lengths for a counterpoise. 8. 6" 10' 7. 1 Term. 52): “A lawyer friend of mine was hired to . •Counterpoise: •Important to have for stable, predictable performance •Length isn’t critical, but little/no benefit for lengths > 0. Rather than carry all those lengths of wire, I decided that something with a few wire segments with quick disconnects would roll up a lot smaller. 5″ for 440) of stranded wire, crimped and soldered to a battery clip. Well, as all the family was Band, Tap point, Counterpoise Length. elevated system called a "counterpoise" or "capacitive ground", with dimensions significantly smaller than λ/4, could be quite efficient. The system has many feet of exact length wire radials built in it. 46 - Piggyback Antenna for 10m. Electrically this gives a complete dipole antenna. Many get away with just using the coax shield as the counterpoise (which some manufacturers advertise as "no counterpoise"). 15m, 6. An HFp was set up for 20-meter operation, and connected to a network analyzer so that the return loss at the base of the antenna could be measured (return loss is essentially the inverse of SWR - the data presented here has been converted to SWR). I coiled the counterpoise on the pack frame as can be seen in the picture. For the two cases where the stock RC-292 uses counterpoise element lengths that are longer than the vertical length the equation is close to: Optimum Frequency = 267 / feet = 3216 / inches. In engineering we sometimes can not directly calculate a value, often when a “divide-by-zero” shows up, as when we try to calculate an impedance wiith a zero maybe better. With the view to establish a quick and easy multi-band antenna deployment for portable and camping operations a simple long wire antenna with an earth or earth plus counterpoise arrangement with a 9:1 voltage unun is one possible solution. 5 ft) counterpoise for 40 m band - 4 m (13 ft) counterpoise for 20 m band - 2. Mountain Parameters 1,594 views. 125 (for 40M) = 135. Be sure your string is least 75 to 100 feet long to go "up and back" down a support structure. 53 - All-Bands Antenna. That’s a lot of wire at, say, 3. 3:1 or better on all bands. If I do that math ( 300 / 7. You can  In electronics and radio communication a counterpoise is a network of suspended horizontal radio waves) drops as their length becomes small compared to a wavelength, so the radiation resistance of antennas on the LF and VLF bands is  Length of counterpoise should be a minimum of 20-30 feet but longer is better. I'm quite impressed with it so far. This makes the ground appear to be a very low impedance at the rig though the length is not ideal. g. You would be looking for increase bandwidth over a single leg. Based upon the zone of protection a counterpoise at 75mm is suitable for 1 to 2 cables and at 150mm for 3 to 4 cables after which additional counterpoise wires are required, as shown in Figure 12-2. 20m. Full Wave Loops. Typically, performance Jan 04, 2017 · We look at the magnitude of the impedance of an EFHW “antenna” for short counterpoise lengths. The coax end was split and center conductor and shield for about 9 inches was bare and connected to the radiator and the spiral counterpoise, this give me a 9 foot tall antenna with a 3 foot square counterpoise on 40 meters. If you are having difficulty getting your rig to tune, start with a 26’ wire. Bands Tap Counterpoise 31' 28' 13'2" 10. The basic formula for determining the length of a full-wave wire Loop antenna is:. Raising the antenna above ground over a counterpoise of elevated ground wires can increase efficiency and input impedance. The model proposed in the paper has been validated by comparing the numerical results with experimental tests. The radio is Xiegu X108G with Elecraft T1 ATU. counterpoise. 2kΩ) so a 1:1 SWR was obtained on my chosen frequency of 21. A very long counterpoise wire can work against this antenna as it begins to appear as a dipole resulting in the transformer that is designed to match impedances in ~2450 Ohms range is now the wrong type. 5 m (98 in) counterpoise for 10 m band. Easy I used a length of copper water pipe as the earth spike. 48 - Double Windom Antenna. The 0. It worked pretty good on 40 & 20m. com and found thIs page on random wire antennas: which got me thinking. A 17 ft (5. 3. You can insert a 1:1 choke balun in the feedline to reduce the problem of RF in the shack but its placement will affect performance. 50 - Collinear Trap Antenna. 78m and 5. If a longer cable length is required, the user may add standard RG-58 A/U cable between the radio and system cable, preferably in lengths that are multiples of nine feet. In fact many use this antenna indoors and it works well, but antenna location is always a compromise of some sort. Without an earth the antenna will try and use the coax as the return path. Longer lengths of wire are needed the lower the band. The calculated values of D{sub e} are compared to those without bond functions and/or counterpoise corrections. Counterpoise Length 160 meters 123 - 136 feet 80 meters 65 - 70 feet 40 meters 34. You do NOT need an additional counterpoise or ground wire with this antenna. 6 feet As you can see, from this table, the length of a counterpoise can be quite long on the lower bands. My ExpertPower 7. I fed them through a 9:1 balun and 50 Ω coax with 25 ft of coax back under wire, possibly acting as counterpoise, but I'm not sure about that. In engineering we sometimes can not directly calculate a value, often when a “divide-by-zero” shows up, as when we try to calculate an impedance wiith a zero Or you can use a single counterpoise long enough for the lowest frequency band and coil it back to the appropriate length for higher frequencies. 5 MHz, but you can loop the wire around the room and hide it from view. MFJ- 1899T Lengths of telescopics are for lowest frequency in band and with ground plane wire connected to radio. The bond lengths are 1. Our results and the available literature data clearly show that extrapolation of counterpoise Prior art date 1931-02-03 Legal status (The legal status is an assumption and is not a legal conclusion. The Medrad Overhead Counterpoise System provides 360-degree rotational mobility for Medrad CT, Angio, and Cardiovascular injection systems and gives you: • Medrad-designed reliability • Strength from single-forged aluminum horizontal arm • Vertical arm flexure compensates for high stress use by limiting torque applied to Overhead plane. This should produce good results on at least 40-6 meters using the narrowest performance range of internal tuners. several different lengths as shown in the table below. ) 160M Is a Tough Band • Propagation quite variable, signals often not very strong, heavy QRN during the summer –Mostly a nightime band, varies a lot through the night –During the winter, 800 miles or Good: Attach counterpoise stud to a radial field of 8 wires minimum, each 10 -20 feet long. that makes a great counterpoise. counterpoise lengths for the U. Counterpoise, in electronics, portion of an antenna system that is composed of wires Antennas may consist of single lengths of wire or rods in various shapes   Vertical Element & Counterpoise lengths (Roll out the single counterpoise for minimum SWR). 3 {18 , 21 & Term. A counterpoise is simply a length of wire laid on the ground and connected to the earth connection on the Paraset. 49 - Double Windom for 9 Bands. Since 2m is a shorter wavelength, we can then  15 Jul 2015 With the 9:1 voltage unun and wire lengths suggested in the below long wire antenna configuration with an earth or earth plus counterpoise. Either use a "counterpoise" at least 0. Dec 28, 2016 · This question can be a bit confusing. The fractal antenna of claim 10, wherein: 32, "An Unorthodox Antenna") is an 84' long end fed and a 17' long counterpoise (6. Howard Long Or a few rotator cable counterpoise wires could be cut/trimmed to the desired lengths and spread out in different directions. Multi-band with antenna tuner. now back to my question 7. A standard recommendation (see QST, March 1936, p. With the matching device at he feedpoint, you can run any length of coax that you want to the transmitter, since the matching device will be showing the feedline a 50 ohm match. On top of that, a RED Buddipole coil. Testing a new antenna for portable ops - Duration: 4:26. **Approximate length of Vertical Element. May 07, 2012 · I read somewhere that the wire lengths need to be balanced, that is equal lengths on both sides from where the wire goes up to the rafters forming a T, is that true? I am a bit fuzzy on the whole thing. 5' for 20m). 25MHz, then I removed the resistor and attached the half wave antenna (6. Unlike many END FED antennas on the market, this one does not require the Antenna Tuner to operate. 3 5' poles in which I installed the CHA250B on to. Figure 1 shows a typical example. 5', 18', 16'  6 Aug 2015 If this is done then the current into any length of “counterpoise” is minimal except when those lengths approach a half wave length. Oct 31, 2000 · in which A and C are constant coefficients for said first motif, N is an iteration number, and D is a fractal dimension given by log(L)/log(r), where L and r are one-dimensional fractal counterpoise system lengths before and after fractalization, respectively. ADD TO CART. More on Random Wire Lengths from Mike, AB3AP (06-29-2012) Hello everyone! I was surfing around Hamuniverse. This mess runs out the window and is arrayed on the garage roof. Counterpoise radials can also be added to improve antenna performance. Learn about the different types of grounding electrodes now >> Geometry optimizations were carried out for the (HF) 2, (H 2 O) 2, and HF-H 2 O intermolecular complexes using the MP2/aug-cc-pVXZ {X = 2, 3, 4, and 5} theoretical models on both the uncorrected and counterpoise (CP) corrected potential energy hypersurfaces (PES). The feed is This antenna requires at least 25′ of coax feed line with no chokes. Figure 6 reveals varying mast lengths alter the feed impedance of our j-pole antenna. But you will introduce another potential source of. Here are the counterpoise lengths that work well with my antenna set-up: - 9 m (29. The length of the counterpoise is not critical. ( Specifications ) Term. Mar 12, 2007 · A remote automatic wide-range tuner, such as the Icom AH-4 or SGC SC-230, between the end of the antenna and lengths of coax and control cable to the shack, appears to me might resolve that problem. ) For example, if you are getting RF problems on 20m (14MHz), a PVC-coated wire or counterpoise cut to a length of 5m may resolve many of the EMC issues. Several sites say the base connects to a tuner with a single wire, but one says it works better with a counterpoise (1 or more horizontal radial wires 5-15 meters long). Line Winder – Plastic winder used to store counterpoise wire. Steve Galchutt, WG0AT, uses a 58-foot wire length with a 25-foot counterpoise. 3 dB gain over a dipole. So if I use a 21 meter long wire, I take a 10. The outside braid of the coax acts as a counterpoise, so it’s important to have the coax on the ground for at least 16’, but again, this is a variable that is not etched in stone. 95. No ground plane or counterpoise is needed. 9 MHz 28. Figure 1 - A typical counterpoise ground system. The counterpoise wires are cut  12 Aug 2016 SWR of 2:1 on 40m with the 36-ft. 5 MHz and 7 MHz Connect Connect wire etc. Based on these results, it is necessary to compute the length of the a counterpoise? I've tried it on the house gutter with various lengths of wire, one down to earth, but the FT-857D complains about swr, on all bands. 4 Term. Sep 05, 2018 · Do You Need A Counterpoise Wire? I find a counterpoise about 17 feet long works well if I want to get on 40 meters. 66. In an electrical sense, a vertical is a dipole with half of its length buried in the ground or “mirrored” in its counterpoise system. Placing the coil about halfway up is a good compromise. Jan 09, 2019 · After much study to include the webpage I made regarding the KISS-SSB, I tried a new-to-me counterpoise system. Graphics by G8ODE DEC 2010 iss 1. Workable: Attach counterpoise stud on unun to a good ground rod at the feed point of the antenna. Hopefully someone on here may have tried it and can pass more info. 02 meters). The KISS-SSB is a US Patented marine SSB ground plane system. In electronics and radio communication a counterpoise is a network of suspended horizontal wires or cables (or a metal screen), used as a substitute for an earth connection in a radio antenna system. The extension of purely horizontal counterpoises with vertical rods has been subsequently considered, adding 1, 2 or 4 rods along each counterpoise; rod lengths were uniformly varied from 2 to 10 m, in 2-m steps. The larger the wire, the wider the bandwidth. Oct 09, 2013 · Counterpoise. Ground based radials can be "tuned" in situ in various ways. 05m respectively. A counterpoise will not be needed when using a mobile antenna like a Tram 1185 or Nagoya UT-72. You can also use the unun with no counterpoise or ground if your feedline is at least 25+ feet long. 51 - Short Dipole Antenna for 40m - 80m - 160m. Trailing Counterpoise Lengths. Fast Setup and takedown. The performance of a monopole antenna is critically dependent upon the associated counterpoise. 1005 ÷ freq (mHz) = Length (feet). 45 - Bisquare Loop Antenna. Notice the counterpoise running from the AH-4 in a circle around the tripod. BNC To Radio. With the view to establish a quick and easy multi-band antenna deployment for portable and camping operations a simple long wire antenna with an earth or earth plus counterpoise arrangement with a 9:1 voltage unun including a tuner or simply with a tuner is one possible solution. Additional grounding. It took a lot of testing to get all the SSB frequencies, Winlink/Sailmail frequencies and long range ham frequencies to work together, the many perfectly measured lengths of copper radials in our system are The Inverted "L" is a 1/4-wave Marconi, fed against ground or a counterpoise such as radials. SWR of the 1/4  Typical antenna lengths for the amateur bands from 160 - 10m, both when using counterpoise length in metres is calculated as 75/frequency (MHz), which  Originally I designed a custom wire for the SLV that was just the right length for 20 meters and used a modified Suggested ground laid counterpoise lengths:. Wire lengths for the 4:1 ratio in models 4932 and 4935. Other pages in this section – Antennas: Antenna Safety It was interesting that most of my counterpoise lengths are very different from what is recommended in “Buddipole in the Field” by Scott, NE1RD, by a good margin. 05 λ. S. Tests show that laying the coax in a straight line is best. Plan View . You can collapse the telescopic pole a section at a time for the halfwave lengths on the higher bands that are shorter than your pole. 9. Oct 03, 2014 · The coax is the counterpoise on the 9:1 balun end fed types and the feedline radiates and its length will affect performance. We also present the critical lengths of the counterpoise for short stroke currents as a function of soil resistivity. Counterpoise as a preventative measure Counterpoise Length. Recommended wire lengths for Unun models 9130, 9132 & 9135 Table shows typical SWR relative to installed wire length. The formulae to calculate the impulse effective lengths of counterpoise wires were proposed. 76 m) V only EFHW-8010-1K ™ Multi-Band End Fed Half Wave Antenna . This is a test anyone can do using one of the new amateur level network analyzers coming on the market. This information from Bonnie KQ6XA appeared on the Miracle Whip Yahoo group some years ago. Counterpoint in the Middle Ages. However, wire lengths range from 20 feet to 32 feet (0. Best performance is achieved with a coax of 16’ or In my case the band to operate will be 80 meters. Mar 20, 2018 · I posted my issues on the Buddistick group site and I got reply saying to treat the counterpoise in “guy wire” type fashion. You can  The antenna wire had a length of 84 ft (25. Amateur radio operator for 40+ years (still learning) I received the antenna this past weekend and installed it on my roof on a professional vent mount. 1/4 λ = 234 / F MHz (Feet) or 1/4 λ = 75/F MHz (metres). 05 wavelenth •Don’t go >0. If it is a single wire or a few wires, they should be insulated from earth and kept a little distance above earth. 5', 18', 16', and 14'. Thanks to Jon AF7TS for the suggestion and discussions that led to this article. Length of the coax is not critical beyond 25′. As usual, Figure 2 —Gain of a quarter-wave 80 meter vertical antenna over average soil, as the number of buried radials is varied, for seven different total lengths of wire. 9. Do You Need a Balun or Unun? I connect my 29-foot cheap HF antenna to a 9:1 unun to lower the impedance. If you want to use the antenna for 80m, the you will need to add a counterpoise, and I suggest using an additional 50 to 100′ of wire. It's a decent match on everything from 40m to 10m, but i was wondering about the effect of the length if the counterpoise. If a metal pole is used for it's support, it's part of the 'counterpoise' too. Note that any of these lengths are going to be long on 6 meters. 50. , G or F below C). The magic lengths to use with the End Fed longwire is 29, 35. I knew it was going to be long so I ordered 200' of 18AWG wire for this test. 2/MHz, m = 15/MHz) or connect the side opposite the antenna to the system ground (return). For some antennas, the antenna is simply not complete without a radial system, or at least a counterpoise. 16:52. With the decline of that site it may eventually vanish along with this valuable information. about 15-20 meter long if I use a 41 meter long antenna wire. The counterpoise wire is installed continuously 75 to 150mm above the cable, conduit or duct bank, or as shown on the plans if greater. where do people get these figures on lengths of coax to use? 3ft,6ft,9ft,18ft,etc. No long counterpoise, radials or feedline required. 23 m) V only 7 148 inches (3. 16 m) H or V 5 106 inches (2. The end fed half wave antenna is an attractive option for many radio hams as it is able to provide multiband operation without the use of traps or stubs whilst occupying a minimum amount of space and not presenting a very ugly visual impact. We continue our antenna offerings with this single band, 80m-10m end fed half wave wire antenna. Expect to experiment and optimise the lengths that work best for you. Portable operation could not be easier. Radials & Counterpoise - Using them with Smartuners™ The SGC Smartuner gets energy into an antenna, but the design of an antenna is what controls what happens to the RF energy from there. Grid dippers are one way Good: Attach counterpoise stud to a radial field of at least 8 wires minimum, each 10 -20 feet long. SSQ Base coil Mar 09, 2010 · How to create a counterpoise for an EFHW antenna is hotly debated. If you are setting up a portable station and plan on using no additional "counterpoise" then just hook up all of your equipment. its resistance under rf load is dependent upon the diameter of the center conductor to the dia. Counterpoise lengths. 1/4À radial for each band Ground terminal AT-130/E 1/4R (quater wavelength) radial for each band is suit- able for a counterpoise. Figure 12-2. This antenna can be hung in many different configurations. Now on to testing the both end fed antennas. 65m) and counterpoise (66cm) from the above calculator. If possible run the counterpoise away from or perpendicular to the antenna wire. It is a self-contained counterpoise radial ground system that is the perfect answer for trouble free Marine SSB It was interesting that most of my counterpoise lengths are very different from what is recommended in “Buddipole in the Field” by Scott, NE1RD, by a good margin. isolated from the mounting structure. The FCP: A 160 Meter Counterpoise for a. In my experience, I normally use the half length of the antenna wire. They did change the resonant frequency and some lengths pretty much did away with the hand capacitance. 54 - All-Bands The coaxial feedline, besides being the conduit for the signal to reach the antenna, serves as a tuned circuit that creates the necessary counterpoise. The results are conveniently displayed in inches, centimeters, feet and meters. To resolve this I followed G7FEK’s suggestion of adding an additional wire about 4m long, which I Counterpoise: A wire or group of wires mounted close to the ground, but insulated from ground, to form a low-impedance, high capacitance path to ground. L : Counterpoise length for the operating frequency [m] The NEC requires that grounding electrodes are under 25-ohms resistance-to-ground (Earth). In this configuration, the coax shield will act as your counterpoise. 5 & 7. Install the counterpoise directly below the EDX-3’s ground terminal. 23 against a reasonable RF ground or counterpoise. radiator and the 13-ft. No ground or counterpoise, just let the coax shield act as your counterpoise. 2. The antenna calculator above uses this formula as a starting point to calculate wire lengths for the dipole. Thus 8, 16, 32, 68 lengths are ruled out. **Length of 4  There are always questions about the length of wire to use with an SGC An RF counterpoise at least 5% longer than the antenna wire is needed, but you might  12 Dec 2010 After our counterpoise length optimization process, the SWR is around 1:1,4 and almost flat in all the 20 meters band (fig. 3 . 13 feet. This length would make the antenna resonant at 14. and a good ship's ground is not available, connect a counterpoise. This model is 1⁄4λ (quarter wavelength) radial for each band is suitable for a counterpoise. c. I got a big roll (a bit over 500 feet of the 22 AWG) and I want to run it through the whole perimiter of the attic 50′ long. to be counterpoise here. We cut three more lengths of wire, wound the unun, connected the  9 Jan 2019 The purpose was to see if I would get any different results against the existing counterpoise I now have. whip lengths shown are only approximate. This is the Portable Resonant system from Alpha Antenna that covers 7 bands with the 5. Length of counterpoise should be approx. 0712 Å for C–H. Thanks to Jon AF7TS  A counterpoise is simply a long, insulated wire that attaches to the ground connection on your antenna tuner. Length is not critical, but best longer than 50 feet. It would be interesting to hear what sort of ground Scott as using when he did his experiments. com The coax connector is at one end of the dipole, where it is most needed. So let’s see — no coils, only half a dipole worth of arms and whips — sure sounds like a lot less stuff than a BuddiPole Deluxe kit with long mast option (which costs $474) Dec 06, 2016 · This antenna works very well. Some designs connect one end of the secondary coil to the antenna socket, which then makes the coax shield act like a counterpoise. To correct this problem, the radial system must be R. 5″ for 220 and 6. In conclusion: are popular lengths. The Tuning capacitor in the AMU can be a 365 - 500pF broadcast type or a miniature version is OK for QRP use. firestik. Firestik Antenna Company - 2614 E Adams St - Phoenix, AZ 85034 - (Tel) 602-273-7151 - www. The purpose was to see if I would get any different results against the existing counterpoise I now have. Actual lengths will depend on several factors including mounting position, coax length, other antennas in the area and matching method. Its fairly easy to do and allows you to use a 23' wire antenna and a 23' counterpoise and get complete 10 thru 40 meter coverage. 52 - Center Fed-Zepp Antenna for 80m - 40m. Three 25′ long lengths of coax tied together at a common ring terminal. Jun 25, 2012 · Although the nominally correct length for a counterpoise is a quarter of a wavelength it must be noted that the optimum counterpoise length is very dependent on the antenna situation, how close to the ground it is and what other grounding (such as power supply cables) is present. It would look something like a folded dipole as your counterpoise. 5 MHz 50. Counterpoise was 5. 6 feet 12 meters 9. 8 and divided by 4 again I get 33 or so feet. 180 ÷ freq (in MHz) = length in feet. I later added Coax ground points along the feeder line. Adding on the wire counterpoise will Counterpoise Correction in Clusters So far, we have only considered dimers. rg-8,rg-8x,rg-58,rg-213 are all 50 ohm coax no matter what length you run. Bad Grounds Can Lead to RF Burns! The instructions give a starting position and length for each band, when used with a quarter-wave counterpoise. 1909 Zepp antenna patent diagram What is the W3EDP antenna? The best way to answer that This site gives a list of random wire lengths to avoid, and a table of "good" lengths, but is silent on the matter of counterpoises. Easy to take with you, easy to set up, easy to make contacts. The Principle of the counterpoise – In the older times, this contraption is used to complete the so called “Marconi antenna” which in effect is a quarter-wave antenna. I look over the chopsticks or skewers and discard the misfits, about 10-15 percent of the lot. Counterpoise definitions can be found in dictionaries. You might experiment with angling the folded part so there is an angle between the outgoing and the incoming legs. Different sources tell you to make the counterpoise wire different lengths, some even say that you don’t need a counterpoise. Since closed loops are not subject to "end-effect" the calculated physical lengths with this formula are longer than corresponding dipole dimensions and are close to free space dimensions. I first tried just letting it hand down but it was horrible, Then I pulled it back under the counterpoise and the feedline is 45-degrees down from the counterpoise. 5″ on 2m, 11. Suggested wire lengths for 1-31 Mhz operation. 6 m), and was installed at a height of 20 ft (6 m). My experiments have shown that with the NVIS 80 meter dipole at 10 feet above ground, and with a 5% longer wire buryied just under the sod, I lose one S Unit of signal strength, but the Noise Level Drops by at least two S Units. And found someone bought one and disassembled it, with no further data, like wire lengths and the such. It is important to use a counterpoise. with wing-nut for counterpoise and SO239 connector Wires stapled to The length of the counterpoise wire, of course, depends on the frequency, and a table of lengths vs bands is provided with the antenna. With the '931 you may be able to get by with just one or two lengths of wire for your counterpoise. The second kind is EFHW which is half wave resonant on the lowest band but is also resonant on all harmonics. Again do not allow the whip to enter the close wound loading coil area of the Hamstick antenna in order to not shear the wire that passes through the fiberglass rod. Snooping around I’ve found bamboo skewers in various lengths and diameters for very little money. meter range. Now with the counterpoise coiled the antenna system is out of the tuning range of T1. of the shield. The counterpoise is the usual length, about 15 meters. The coax connector is at one end of the dipole, where it is most needed. 41 meter (17 foot 9 inch) stainless steel telescopic antenna element as a Vertical with the optional counterpoise installed, or as a Dipole with optional extra element. If you had it thrown over a tree limb the only catch would be the wire end catching on the branches. John MacDougall, KA4WJA concludes that random lengths of wire cut near the operating frequency can be used to the same effect as the KISS-SSB. Figure-1a. Band. The length of the counterpoise is equal to one half the length of the vertical antenna, connected to the ground element of the antenna and doubled in the opposite direction. 3 CPE int (ABC) = EABC ABC (ABC) EABC A (A) EABC B (B) EABC C (C) (4) The 0. 5 meter length or irregularly spaced radials, or any. Probably the main area of disagreement between these two commentators relates to the length of an effective counterpoise. Guy Kit 200 ft Voyager Counterpoise Assembly $ 79. F. A counterpoise is simply a long, insulated wire that attaches to the ground connection on your antenna tuner. The best counterpoise is 1/4-wavelength at the  This is a great antenna for portable operations and will work best with the counterpoise lengths suggested. 6 deg) Tuning the antenna element to resonance first (using a dinky ground plane…or a good one!) is prudent, because it is very tricky to simultaneously tuned the antenna and the counterpoise. Requires antenna tuner. Alf. 5″ DUAL BAND 144/430Mhz U/V SMA-F Antenna arrived today, and even though it’s only 2″ longer than the stock BaoFeng 5″ antenna, you can tell that it is much better than the stock antenna. Aug 22, 2016 · The antenna cannot be an actual 1/4 wave length on any ham band. My counterpoise is about 50 feet (for an approximately 75 foot antenna) and I can reliably work domestic DX and occasionally foreign DX with only five watts the seven different total wire-lengths spanned the range from 500 feet (just less than one wavelength of wire) to 32,000 feet (almost 60 WL). The shield of the coax acts as a counterpoise. The antenna base-loading coil or capacitor is a reminder that ground reactance is tuned-out by a tuner simultaneously with the antenna input reactance. 25 feet of coax (using the supplied commercial Buddipole coax). 2 m) long "counterpoise" wire (6. Number of sections Extended length Application 3 64 inches (1. 2 MHz 24. The author claims he found seven different wires connected to the one wire for the tuner. 40-30-20-17-15-12-10 . This calculates to ≈ 4. Some say you do not need a counterpoise, but that is false. If wire length was relevant, each antenna would need 22. A 33’ X 1″ coated steel tape measure was used as an adjustable counterpoise. It may be used with many of your antenna projects where a 4:1 Unun is typically recommended. Our Patent-Pending KISS-SSB principal is "Icom Endorsed". The artificial ground and the antenna tuner interact a bit, so I make a small change to one, then adjust the other, then repeat. These are for counterpoise wires that trail on the ground. Then I tried a 25 foot feedline without any counterpoise and the hand capacitance was gone! Aug 31, 2017 · The other end has a shorted 1/4 wave length (corrected for cable VF) of coax as a counterpoise. Its a compromise but  All vertical monopoles need some form of counterpoise in which antenna image currents flow to work effi- ciently. 75 turns, and the coax shield connected at about the 2 ¼ turn point from the center starting point. You can experiment with different lengths. quarter wave in length, can often provide an upset to the counterpoise created by the radial system, and act as a vertical dipole instead of the desired ground plane. The wire for a counterpoise should be a quarter wavelength at the lowest frequency used. 0 When using other than 3. 2 m or ≈14 ft ExpertPower XP-669C 7. Here is the configuration (thanks to PD7MAA): This assumes the stub is RG-58 with a velocity factor of 0. 1 MHz I've just built an end-fed wire antenna and am using a 9:1 unun to feed it. The length of counterpoise should be a minimum of 30 to 40 feet but not the same length as the antenna wire. You can calculate the antenna radial length you need for a particular frequency of interest using the following formula: Length = 234 / frequency. 52(A)(5) in the 2017 National Electric Code (NEC). 69 m) H or V 6 127 inches (3. squib reference DOI; 1945Herzberg: G Herzberg" Molecular Spectra and Molecular Structure II. Aug 10, 2017 · END FED, 1/2 WAVE, 40-10M, 300W, WIRE ANTENNA FULL HF Coverage, no tuner needed on most frequencies. One way or another there is always a counterpoise involved if the antenna is tuned correctly. 25 wavelength •Watch out for the high voltages (at X) •At 5 W (and 2000 ohms), V CAP (Peak) = 100 V •At 100 W (and 2000 ohms), V CAP (Peak) = 450 V •At 1500 W (and 2000 May 24, 2019 · There is no 'proper' length of coax for a counterpoise for an A-99. Again, for me at HF, a full-size counterpoise at anything below about 21Mhz was going to be a non−starter on a train. If possible, run the counterpoise away from or perpendicular to the antenna wire. It may require a good tuner if you want to work the low bands on a short wire. While these lengths have been shown to work well on many  the second section titled “Recommended wire lengths and Configuration Shorter length counterpoise wires can be used if operation is confined to 40m or   A counterpoise is a conductor or system of conductors used an earth or ground should consist of buried radial wires at least one-fourth wave length long. The earliest examples of actual written counterpoint appear in the late 9th-century treatise Musica enchiriadis. We look at the magnitude of the impedance of an EFHW “ antenna” for short counterpoise lengths. Jun 12, 2019 · The figure 8 – blue line (grounded end) is exactly what I am experiencing with my end fed strung at my back yard. A third method is a commercial product, the KISS_SSB, that uses a number of wires of various lengths bundled together and connected to the antenna. 9). MFJ makes a great little multi band, adjustable whip antenna that can be added to your KX2, KX3 or almost any QRP radio. Postage-Stamp Lot a counterpoise at WØUCE — at 2. Aluminium clamping plate . 6m long, how would I figure out how long the counterpoise should be? I have used both 107 and 71 ft lengths, but didn't see much difference as my old KW At-230 tuner tuned both just fine. A counterpoise, like Jim said will help, but a good ground is essential if you want it right. If the current is  25 Jun 2020 DX-35CP, DX Store Counterpoise kit for HFJ-350M/HFJ-350M Toy-Box (or similar antenna), 35FT length, suitable for 6M-40M, includes wire,  including use as a wire counterpoise for our vertical antennas, as well as wire off the ends of our coils for. In order to satisfy resonance , proper matching and efficient radiating properties, a quarter wave element is added to complete the antenna circuit. 1. The Wire Size can range from 16 AWG to 12 AWG. It does not require any holes under the water-line in the hull for a bronze plate, copper foil or copper mesh. Attach the length of random wire to the red binding post labelled “To Counterpoise Wire or Ground Connection Wire” on back of the MFJ-931. 7 MHz 5. Installation Notes There are several methods of installing the antenna and some are better than Ahh, the good old quarter wave ground plane! This calculator can be used to design a Quarter Wave Ground Plane antenna, with radials. With the EFHW the earth (or a counterpoise) is still important, but not quite as crucial. Here is an interesting quotation from Laport[14] regarding counterpoises: 5 hours ago · MY FINAL SET-UP: I started my experiments with. 3 feet 17 meters 13. A standard Buddipole stainless steel whip is on top So, after a splice and another cut, I can now officially > announce that a 58 foot "random" wire with a 29 foot counterpoise will > give a 1:1 SWR on all bands 80-10 on the KX2 using the KXAT2. NVIS antenna. Counterpoise If your ship is made of FRP, etc. 5, 41, 58, 71 and 84 feet To use the counterpoise: Refer to the following chart for use. All LJ parameters are mixed by Lorentz-Berthelot rules and summarized in Table S1. With two variables - counterpoise length and coil setting - how  Some recommendation are made concerning the use and characteristics of earth electrodes, for example effective counterpoise length, where to locate  Length of counterpoise should be approx. I was experimenting with various counterpoise lengths yesterday with my 40m end fed. On higher floors you'll need a counterpoise. The total length is 66' and the price is $27. The coupler can be adjusted to compensate for any reactance that may be present due to other lengths but it is around this length where the whole antenna system is the most stable and provides a purely resistive As stated before, a counterpoise is only useful when using actual handheld antennas as a portable. A great addition to my Go-kit or any portable operation. A radial/counterpoise field is not necessary with this EFHW wire antenna. Any counterpoise should be at least 1 foot above ground running away from, or perpendicular to the antenna wire. The radials can be any length and they work. Fed by ¼ λladder line into a balanced tuner. Here is a handy chart for determing 1/4 wave verticals, 1/2 wave dipoles, and full wave loop lengths. Additional short lengths may be placed for other bands if needed. Other designs, such as the popular commercial EFHW-8010, connect it to s separate screw/output so that you can either connect a short counterpoise or connect it to a ground rod. I particularly want to know how counterpoise affects the common mode currents on the coax. I used 4 lengths of wire at 33. S Term. ) BAND, LENGTH, WIRE SEGMENTS. 3 MHz 7. Recommended wire lengths for Unun models 9130, 9132 & 9135 Typical SWR relative to wire lengths. 6m long, how would I figure out how long the counterpoise should be? The usual way of feeding an end fed half wave is against a short counterpoise, but I Using lengths of PVC-coated wire of 10. It just cannot connect back to the station entrance ground, or the balun's ground. One of these tuners mounted well away from the shack, and close to the ground to feed the required radials, also offers the opportunity to turn an The following discussion about the KISS-SSB marine counterpoise system was posted in the SSCA website forums. 6 to 0. Ok, I have read all the reviews and searched for all information regarding the Comet CHA250B antenna. The size of the required coil increases with height. G5RV – 102 ft. The radiating element is a quarter wave (λ/4) and the radials are 12% longer. Counterpoise Correction for Energies of Hydrogen-bonded Dimers. 5 ft for 20m) was connected   You are here: Calculated > Energy > Optimized > H bond with counterpoise. This formula to obtain the length of a half-wave dipole antenna will give a good ballpark value to start with. Shorter length counterpoise wires can be used of operation is confined to 40m or higher. 2111 Å for C–C and 1. Stranded wire : 3. Without adjusting the variable capacitor, I had a 1:1 SWR. On frequencies below 18MHz the inverted L performed better than the G5RV, but on 18MHz and above it was much worse. What about 5 ft? I played around with some short counterpoise wires to see how that would change things. Quarter-Wave Vertical Antenna Length Calculator. Only 1 or 2 rods per branch have been considered in the 500 Ωm earth resistivity case. So, I mounted the Buddistick on a tripod about 4 to 5 feet off the ground with the counterpoise heading in an angle back to the ground and “Voila” the whole world opened up to me. 5 meter long counterpoise. 2 {14 & Term. The traditional 8-ft length of rod and pipe electrodes is located at 250. If space is a problem zig zag or some long and some short ground wires is a backup  4 Jan 2017 “Counterpoise” Length. Parts of the Counterpoise Kit The CHA COUNTERPOISE KIT is comprised of the following components, see plates (2) and (3): a. With two variables - counterpoise length and coil setting - how do you know which is optimum? It is clear that a willdly wrong counterpoise length results in broader tuning of the antenna, and obviously lower efficiency. 3 Nov 2015 Looking at the simple math for a quarter wave, it is 234 divided by Frequency equals length in feet. MEDRAD® Mark 7 Arterion Sterile Disposables * Refer to the Operator Manual for a description of the intended use, contraindications, warnings and instructions for use. 200 MHz. Jul 22, 2014 · A simple, inexpensive and effective expedient to improve a “rubber duck” antenna is a counterpoise or “tiger tail”. 05 wave lengths long (ft = 49. Although the nominally correct length for a counterpoise is a quarter of a wavelength it must be noted that the optimum counterpoise length is very dependent on the antenna situation, how close to the ground it is and what other grounding (such as power supply cables) is present. The W3EDP end-fed antenna is a cheap way of getting multi-band operation, especially if you are a newcomer and restricted to 10W. Since the wire is insulated, it probably appears to be a slightly longer wire to the antenna tuner, which is an Icom AH-4 sitting at foot of the antenna. 70m diameter Loop. You may find it helpful in working out what lengths to try. Infrared and Raman Spectra of polyatomic molecules" 1945 Van Nostrand. It could work without counterpoise (Coaxial cable has to be at least 25 feet long) but grounding at wing nut next to the connector is recommended. Draw it on graph paper if you like. For a transmitting station one of the easiest ways is to monitor the reflected power on a voltage standing wave ratio, or VSWR, meter. You may need to try different wire lengths to optimize your antenna configuration. So you can either just connect a single wire from the base to the center pin of PL-259, or better, run 1 or more counterpoise wires, connected to coax shield. Up and down position change The figure above shows that terminals O and 5 are shorted when using SO MHz. 20 May 2009 Buddistick setup on a tripod with single counterpoise. Layout the radial horizontally and as straight as possible. Longer length radials are not necessary. See the illustration below depicting a top-down view of a vertical antenna with the counterpoise spread around the vertical element 360°. are the lengths recommended by Balun Designs for their 9:1 UNUN and I thank "An Unorthodox Antenna"): an 84' long end fed and a 17' long counterpoise  NOTE:- The antenna wire is cut to the length calculated by the formula ;. Counterpoise Wire – 25 foot wire for use as antenna counterpoise. This calculator is designed to give the vertical length (height) of a quarter wave ground plane antenna, and the length of each of the four radials counterpoise impedance, the more current will flow in the outside of the coax shield, so its a trade off. 1 MHz 14. (antenna, coax and counterpoise lengths) How to match the antenna to coax cable (matching unit values and placement) Choosing a configuration that fits the location (vertical, sloper, inverted L, horizontal options) Choosing a feed line choke or noise filter (selection and installation) How do these steps apply to your end fed? Feb 08, 2014 · Your body acts a counterpoise, and the antenna is somewhat tuned to have a decent impedance when it is held, but your body is a poor conductor so it’s lossy. Install the counterpoise directly below the AT-130/E's ground terminal. It shows which wires to use to get the right length of counterpoise for the band you are working. lengths of High Pressure Connector Tubing enable flexibility in injector placement and configuration. counterpoise lengths, adjusting the counterpoise lengths for the (80 – 6 meter bands), and recording the SWR measurements taken with my AIM-4170C. The model proposed in the paper has been validated by comparing the numerical results with experimental This worked quite well when fed with a 4:1 balun at the base and the remote auto-atu. While these lengths have been shown to work well on many bands, which is helpful if you're in a hurry to get on the air, read up on the topic and experiment. Here is the definition of "counterpoise" appearing in the Communications Standard Dictionary: A counterpoise is a conductor or system of conductors used an earth or ground substitute in antenna systems. 14. It is used with radio transmitters or receivers when a normal earth ground cannot be used because of high soil resistance [1] or when an antenna Length of counterpoise should be approx. Since the band in question is 80 metres the  or random length counterpoise system. Click on an  of wire, tabulating results and progressively cutting lengths off until the best performance as obtained. A ttaching a counterpoise wire to the common point of the auto-transformer provides the antenna radiator something to push against rather than the coax shield. I've just built an end-fed wire antenna and am using a 9:1 unun to feed it. 5 feet 30 meters 24. coax is coax. 8 feet 10 meters 8. For example a 32 foot length is actually a half wave on 20m with an impedance of about 3500 ohms and requires a 50:1 balun. When catching an RF signal, "negative is just a phase change - you can divide the signal in half (6cm) and say it starts and ends at zero. ) Expired - Lifetime Application number US513063A Inventor Brucc Edmond Current Assignee (The listed assignees may be Sep 01, 2015 · Short Vertical Tuned Antenna Impedance with Spiral counterpoise 20 ohm Z with almost 0 reactance (-1. counterpoise lengths

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