How To Lower Swr On Antenna


If the SWR remains unacceptably high (greater than 2:1) at the lowest point, it means the antenna is resonant in the band of interest but the impedance of the antenna is not near 50 Ohms. thanks, im new to this. SWR meter readings take into consideration the antenna, the coaxial cable, the mount, the mounting location, the vehicle and objects in the antennas near-field environment. – No, pattern may change from that at resonance and will need to match. When you put your amp in line and check the SWR with it on high it should read slightly higher , no more then 1. What this means is the stainless steel whip type antenna will. What is SWR ? SWR (Standing Wave Ratio) is a measure of the antenna efficiency. When I cut it, the SWR gets higher overall but it is still better at the lower side of the band. 40 will get higher as the SWR on channel 1 gets closer. I prefer an SWR of under 1. ZS6BKW antenna is derived by the popular G5RV dipole antenna, but offer more bands a lower SWR on most bands and radiation angle making suitable for DX About The DXZone The DXZone is the largest human created and maintained library of web sites dedicated to Amateur Radio, currently lists 20. 000 000 MHz STOP CHI. See if yours is anywhere close to 4 MHz, even if it is outside the band. However not everyone has 6 or 7 monobander antennas laying around the yard, and many amateur radio operators use wire antennas on the lower bands, so I understand why sometimes you need a tuner. A shortened multi-band End-Fed Half Wave (EFHW) antenna for 80-10m Steve Nichols G0KYA A shortened multiband antenna, about 23m long, for 80m-10m that offers low SWR (1. This allows for more aggressive use of an antenna tuner without the risk of damaging the matching system, which increases the usable bandwidth of the antenna. Clicking this. Oh and don't get super hung up with low SWR. 1) and SWR of last channel (23 or 40) 3. • Measure an existing antenna or: • Export antenna design from NEC • Import data into Sim Smith, use it to design matching networks –Stubs –Matching sections –Capacitors, inductors, transformers. For the initial tune up a SWR analyzer is nice to have if you have access to one. VSWR stands for Voltage Standing Wave Ratio, and is also referred to as Standing Wave Ratio (SWR). 28:1 and essentially FLAT across almost the lower 2. HOW TO SOLVE YOUR ANTENNA MATCHING PROBLEMS. Place the other hand around the small tub- ing and the thumb of this hand on the wire. We can see that the 9. I spent about 10 min straight testing the SWR in all of these conditions. SWR should be check at the lowest power that the meter will read. 8 volts, but in a car, it will change. Once we had both antennas tuned, we combined them with the 2-way power splitter and measured the SWR of the combined array to be 1. Loosen the mast set screws and raise the whip 1/4", re-tighten set screws, (steel-whip only). See if yours is anywhere close to 4 MHz, even if it is outside the band. You should be able to duplicate these results without too much trouble. 9Mhz unless something has changed with your existing antenna system. Setting the antenna SWR with an amplifier can get involved. 6) You CAN operate your rig on an antenna system that exhibits a significant SWR – WITHOUT DAMAGE due to SWR. And found that all this did was make the SWR even lower around 1. I am amazed - from the time I opened the box. A Narrow-Band Hoverman. Maco V 5/8 Antenna Review Choosing a base station antenna isn't easy. Be sure to wind 6 to 8 turns of coax about the diameter of a coffee can at the feedpoint to keep RF out of the shack and to provide a higher impedance path for lightening. – Both coax and ladderline can have catastrophic losses under high SWR conditions. now it’s back to prove its legendary status once again! A Full-size radiator with lower radiation angle concentrates power closer to the ground, where you want it. continued 2 Switchto the CAL position. different power readings from different radios will change it very slightly (the SWR), if the antenna is grounded well the match should stay fairly the same with other radios of the basic same caliber. An SWR level of a 3. Take a look at this video to ensure you have matched your antenna properly to get the best performance! Website link. Ensure meter has correct frequency range: VSWR meters are typically designed to operate over a given frequency range. 6) You CAN operate your rig on an antenna system that exhibits a significant SWR – WITHOUT DAMAGE due to SWR. You need to find that magic "constant" number that was arrived at by your final tuning result of your 75 meter antenna when you first finished it. I use a CB SWR meter to check 2M antennas all the time. Your radio expects a 50-ohm impedance, but the impedance of an end-fed wire is much higher, on the order of thousands of ohms. RadioWavz Dipole antennas are the simplest practical antennas from a theoretical point of view; current amplitude on such an antenna decreases uniformly from the maximum at the center to zero at the ends. Expect to hoist and lower the antenna several times before you get it just right with the minimum SWR where you want it in the band. Take a look at this video to ensure you have matched your antenna properly to get the best performance! Website link. Saturday, June 23, 2018 How a simple counterpoise system can lower your SWR. Solarcon GPK-1 Ground Plane Kit For A-99 Antenna (1290) Solarcon GPK-1 Ground Plane Kit For A-99 Antenna The Solarcon GPK1 ground plane kit used with the Antron 99 (A-99) base cb antenna is intended to lower the angle of radiation for a slight increase in range. These radial wires will provide the needed electrons to move up and down the antenna, but they do not help hold the signal down along the surface of the earth. Then check the SWR at the “target” frequency, 100 kHz below the “target” frequency, and 100 kHz above the “target” frequency. The antenna subsystem is the most important part of your CB system. The radio and Firestik kit are brand new and everything seems to be working fine except I can't lower my SWR. Additional Info on Feedline Length with Multi-band Dipoles: Feedline length is critical to antenna tuning and performance. antenna doesn't resonate inside the band, you can find the resonant frequency with a noise bridge and a general-coverage receiver. I did this for 30 minuets with no luck getting my swr lower than 2. As I wanted to reduce the SWR value in the lower bands I now tried to connect a radial roughly in the 40 m band area, hoping that it may effect the curve. Generally speaking, the lower the ratio the better. com in Norway. There is a trick to it however. Pierre KD2EPQ Sent from my iPad using Tapatalk. Trimming the length of your coax will trick your SWR meter and you in to believing your SWR is lower. Now switch to channel 20 and make your adjustments to either lengthen or shorten the stinger. The advantage of using this formula is that it is simple and thus easy to implement using JavaScript. Antenna matching Trim the length of the dipole for best SWR across the band of interest. When the antenna begins to ice up, the antenna elements are lengthened, resulting in a better match at the operating frequency. At the output of the reduce cable did 2 turns of cable to get the throttle shutoff and symmetric inductance. A high VSWR is an indication the signal is reflected prior to being radiated by the antenna. The antenna light comes on on channel 20 sometimes and always when I talk into the mic. Problems solved. 9Mhz unless something has changed with your existing antenna system. Most antenna tuners work best into high impedances, rather than low impedances. The SWR, or Standing Wave Ratio, is a measure of how well the impedance of the transmitter (or receiver) matches the impedance of the antenna system. The SWR adjustment procedure is in the electrical diagnostic manual. It allows you to tune your antenna, which is adjusting the length of the antenna for optimum performance. However, it is possible to move the transmit frequency and get a lower reading, but the antenna is no longer resonant!. If the SWR remains unacceptably high (greater than 2:1) at the lowest point, it means the antenna is resonant in the band of interest but the impedance of the antenna is not near 50 Ohms. Please see screenshot of Wire Dia vs SWR & Gain below: Table of SWR & Gain vs Wire Dia: franklin wire size. 2 and for the 70cm band I get a swr reading of 1. This 3 to 1 “Standing Wave Ratio” is a polite way of saying “loss. Verify your SWR: In most cases you're looking for the. Be especially vigilant for changes in the frequency of minimum SWR, which can indicate connection problems or water getting into the antenna or feed line connectors. By adjusting the coupling loop, it's possible to get a very low SWR on several ham bands (e. " Therefore SWR is concerned with matching the antenna to the signal being transmitted through it. 40 will get higher as the SWR on channel 1 gets closer. If you are alone you are gonna have to test swr, open the door, twist the knob, then get back in and try again. If the antenna reads too long or too short you can generally adjust the length of the radiating element a little bit to even out the ends of the band. If you tune the antenna badly, it can turn your CB radio into a useless brick. When I cut it, the SWR gets higher overall but it is still better at the lower side of the band. This video should also help with home base antenna tuning as well, as. In general , a low SWR means that the antenna is matched well to the radio, and that everything is working properly. Thicker wire will lower the Q, reduce resistive loss and make the half-wave dipole less frequency conscious. Note the increase in line loss as SWR on the line increases. It would be like saying how can you differentiate degrees F from a furnace. High loss coax can really reduce your output power. antenna doesn't resonate inside the band, you can find the resonant frequency with a noise bridge and a general-coverage receiver. However, I have done a lot of research. If the low edge has the lower SWR the antenna is too long. N7VE LED SWR Bridge v3 – March 29, 2012 Page 5 of 10 After winding the RF step up transformer as above, clip one side of the 5T tap loop. Due to its high SWR, an impedance matching device is required to be incorporated in the feed coax (i. So the strange observation is the SWR indicates the antenna is too long (better on lower band edge). The G5RV is a special antenna, but does make any miracles. I personally think you should resize your antenna to get to a good SWR once and you won't even need a tuner at all. While they might get away with it the duty cycle on transmit is reduced. 1 of fluctuation is ok. If you find that there is more than one minimum, work from the lowest frequency one. SWR stands for Standing Wave Ratio. If channel 1 is higher than 40, raise something on your antenna. 00 by Tony, i2tzk Page. Let’s talk about setting the SWR’s. The radio and Firestik kit are brand new and everything seems to be working fine except I can't lower my SWR. A high VSWR is an indication the signal is reflected prior to being radiated by the antenna. Plus, the SWR shown here is measured at the antenna, not at the radio. “A´ might be the power applied to the connector on an antenna, the input terminal of an amplifier or one end of a transmission line. Standing wave ratio (SWR) is a numerical value used to indicate whether the antenna, feeder and transmitter match. The 200Ω low-inductance load resistor (thick film) was connected directly across the short output wires and the balun was without a box. If you get 1:1, then the cable impedance is 50 ohms. I will run a simulation for this antenna, one with straight radial & second with bent down radials, and compare the radiation pattern of two to get a conclusive opinion. I then added in a 4" spring to the mount. However it is found that if the coax feeder can withstand the higher voltages and current as a result of the poor antenna match, and the feeder loss is not too high, then the system will work well. You may notice that some antennas that exhibit very low SWR are not necessarily the best performers in your application. A radio for 477 MHz with a UHF connector can't expect an SWR of 1. Similarly, NEC-2 predicts. Buy WORKMAN SWR-2T CB RADIO ANTENNA SWR METER at Walmart. A perfect antenna would have an SWR reading of 1:1 - meaning that all the power transmitted up the. •An Antenna Analyzer can help you find problems in your antenna system. It allows you to tune your antenna, which is adjusting the length of the antenna for optimum performance. Measuring SWR with the meter above is described below: You set the sliders of the meter to positions FWD (Forward) and SWR. Even though the VSWR is relatively high on 75 and 80 meters, lower coax loss on that band at least lets us operate there using just one multiband antenna. In laymans terms, the coax length fools your SWR meter into thinking that your SWR is different to what it actually is !. the SWR is where you want it, tighten the clamp bolts. Mobile antennas with the lowest unmatched SWR perform best 11. Under certain conditions a wide range antenna tuner may be required to obtain a lower SWR. It was back before the internet so you had to wait for the license to come in the mail to find out what your call sign was and get on the air. Procedure: The SWR meter needs to be placed in line between the antenna and the CB. I specialize in a certain type of antenna called a J-Pole. The EU band is lower in frequency than the UK band - the lower the frequency, the longer its wavelength (which translates to length of aerial). Dipoles need to be half a wavelength long, locating these long antennas can be an issue, especially when we are aiming for the 80 metre band or lower. The measured SWR curve of the antenna is relatively close to the SWR curve predicted by the EZNEC model of the antenna. Although both current and voltage standing waves are set up, it is often the voltage standing wave ratio that is more widely discussed, as a result of the fact it is easier to detect and measure. Higher or lower seems to work best. When you purchase the Trunk Lip Mount version of the K40, the antenna body comes in a box and the 58" steel whip will come packaged separately due to its length. My workshop under the garage needed to have a separate antenna, preferably hung from a nearby tree. The transmitter will warm up much quicker with a higher SWR as compared to a lower SWR. The Monkey Made MM-10-Medium is an air cooled CB antenna made tough for professional drivers: Hear better, transmit further, maintain better SWR's across a broad band, and handle 20,000 plus watts. All the shortening or lengthening will not bring the SWR down any lower. We can see that the 9. Tuning can be done somewhat independently on each of the bands. “A´ might be the power applied to the connector on an antenna, the input terminal of an amplifier or one end of a transmission line. To measure the return loss of a device or antenna, first open or short the test port and observe the signal level at the output port. I also bought an swr meter so that I could properly tune the antenna for best performance. Lower SWR on Helix13 from Wimo The QO-100 satellite uplink is in the 13-cm band. I needed to take about 2 feet off the horizontal section to get mine resonant at 1830. Generally, you should strive for a low SWR in your antenna system. Greetings antenna experts! I am trying to figure out why the lowest SWR reading I am getting with my 40 meter dipole (flattop) is 1. The SWR is minimal in all bands and no tuner need. SWR stands for "standing wave ratio". ) raise the whip slightly. On the contrary a lower than normal SWR over a significant bandwidth is reason to suspect that a dipole antenna or a vertical antenna is being affected by resistance losses that may arise from poor connections, poor earthing systems, lossy cable or other causes. biconical antenna since it has a high VSWR at some frequencies. To accomplish this, the tuner will have several controls and dials (knobs) used to set and fine tune it. On paper the antennas should handle twice the legal limit. Next trim the leads as shown below: Figure 5. When building antennas for the Wifi band ( Like the 8dBi omni ), a need for an easy way to check the antennas arose. When you put your amp in line and check the SWR with it on high it should read slightly higher , no more then 1. Calculate Zcable at the frequency where the SWR is maximum, or use the graph below:. Once we had both antennas tuned, we combined them with the 2-way power splitter and measured the SWR of the combined array to be 1. If the SWR meter pegs, you have a short in the cable or connections - do not operate the radio. 2 and for the 70cm band I get a swr reading of 1. In a perfect world, this is the best way. The removal of these seals will expose a wire which is terminated to the end of the outside metal cover. According to my research, if your SWR reading on Channel 40 is higher than t. SWR should not be the only meaning given to how an antenna “works”. Mount it to the rooftop,natural wind drag will get you under overpasses,but it's a bummer in the woods or at burger king hence the spring and clip. You need at least 3/4 of the antenna above the roof of your ground plane or car roof. Introduction. The W0BTU antenna covers more bands than either the G5RV or the ZS6BKW. Choose the position among all switch positions that shows the lowest SWR. Next, you can go to 15 meters and raise the antenna until you get a SWR dip there. Connect the antenna (normally connected to the back of the CB ) to the connector marked "Antenna" or "Ant" on your SWR Meter. SWR stands for "standing wave ratio". Remember, paint and primer are your enemy. Although this antenna has no adjustment for SWR i was a bit wary in case the SWR ended up being higher than i'd like but although an SWR of 2. I have an SWR/Power meter and an antenna analyzer, and I don't know at this point how I got along without them. All CB antennas are tunable. To accomplish this, the tuner will have several controls and dials (knobs) used to set and fine tune it. However, if you are among those that have been searching for answers to [how to draw radiation pattern of antenna, types of radiation pattern, types of antenna and their radiation pattern, antenna radiation pattern pdf, radiation pattern of dipole antenna, radiation pattern of antenna ppt, how to read antenna radiation pattern, antenna radiation pattern measurement, Electromagnetism. An SWR up to 4-5 is okay with a tuner, with little loss of performance if you use low loss coax. GENERAL INFORMATION The MFJ-941B is designed to match virtually any transmitter to almost any antenna, including dipoles, inverted vees, verticals, mobile whips, beams, random wires, and. I used a 50 mm grey PP drain pipe according to EN 1451 B or DIN 4102 B1 which I found in the local Do-It Yourself store. I am finally getting around to do the install soon for a new base antenna coax new mast etc on a new house and I am going to use a Sirio Star Duster M-400 and by the way this new antenna is built surprisingly well everything machined spot on and not one ill fitting part Anyway I do not know how you adjust this antenna for proper swr alignment?. Sure, the antenna is 10kHz between the 2:1 SWR points, but if you can tune that 10kHz anywhere you want between 5 and 21 MHz, who cares?. SWR can only be accurately determined at the antenna 9. If you want to fix it, the simplest is probably to join the coax where you cut it. When the antenna begins to ice up, the antenna elements are lengthened, resulting in a better match at the operating frequency. 5 or less Obviously, these are unsuitable for DIY antenna making by a normal ADS-B hobbyist, who does not have any test equipment and any technical know-how. It performs best if it is isolated from the mast. Push the PTT to start the transmitting, pay attention to the SWR meter, if the SWR value is high, tune the lower tuning knob on the antenna to start the impedance matching. Take caution here; stay away from the antenna and don’t touch it or the top of the stud mount. 000 000 MHz STOP CHI. One of the only sites to explain buried radial vertical antennas. The removal of these seals will expose a wire which is terminated to the end of the outside metal cover. While calibrating, if you get the lowest reading on channel 1, then it is understood that you need to reduce the length of your antenna whip. The PK antenna analyzer (PKAA) is a low cost, full-featured instrument with many unique features: VSWR measurements covering all amateur bands – continuous scans can be done for any frequency between 1-30MHz. This antenna has been calculated using 14 AWG stranded copper wire, with the jacket on. If the SWR is lower at the lower frequencies then it is too long. When I measured the SWR, I stopped using the antennas until I can reduce the SWR. Using the Modified Screwdriver Antenna as a Base Antenna Hot Rodz® works for base systems as well as for mobile antennas, enabling you to operate at lower frequency bands than you might be otherwise able to do. SWR (measured with an SWR meter) shows you how well your coax, antenna mount, ground plane and antenna match the output capability of your CB radio. Using them outside this range can mean they are insufficiently sensitive and the full scale defection in the forward direction may be difficult to achieve. A quarter wave works better than a random wave antenna because of harmonics, I think that's the right word. At the radio, SWR would measure significantly lower because the lossy feedline absorbs reflected power. Setting the SWR of Your Antenna. ) raise the whip slightly. I specialize in a certain type of antenna called a J-Pole. The cold side is mounted in the 3/8 x 20 hole at the near center of the UM-2 Universal Mount. I think the word your looking for is Standing Wave Ratio(SWR) NOT RF ??And yes one should have an SWR of 1. Additional Info on Feedline Length with Multi-band Dipoles: Feedline length is critical to antenna tuning and performance. Standing wave ratio (SWR) is a numerical value used to indicate whether the antenna, feeder and transmitter match. 1 : 1 across the entire band! 40 Meters Setting my antenna analyzer for a frequency of 7. Transmitting with excessive antenna "mismatch" or standing wave ratio (SWR) will cause many radios to automatically reduce output power to avoid damage. Switch back to SWR and record the readings on three channels; 1, 20, and 40. 6 :1 in the example above, our percentage of reflected power would be 5 % with 95 % of transmitter power usable or 95 watts to the antenna assuming no other loses in your feed line or antenna. The project is focused on measuring the antenna SWR performances across all the HF Ham radio bands without any need for the transmitter to be connected to the antenna. The PK antenna analyzer (PKAA) is a low cost, full-featured instrument with many unique features: VSWR measurements covering all amateur bands – continuous scans can be done for any frequency between 1-30MHz. See how the SWR. Want Answer 0. The AT5K optimizes the performance of your antenna and transmitter by providing adjustable impedance matching using a T-type circuit con˝guration. Their use and popularity peaked during. How to make a Simple Dipole Antenna It is very easy to create a simple 1/2 wave dipole, all you need is some lengths of wire such as the core of some mains flex or even a straightened out metal coat hanger, some co-ax cable and a connector for your scanners antenna input (usually BNC or SMA). The lower the signal (left side of the FM dial) the longer the antenna needs to be; and inversely, the higher the signal is, the shorter the antenna length needs to be. Sold by JBTools and ships from Amazon Fulfillment. You can get an SWR reading that is as low as 1. The radia- tion resistance of a horizontal dipole can. It is assumed antennas are remote from the ground - heights greater than 0. A half-wavelength radiator has a high impedance (high voltage, low current) at the feedpoint. My previous simulations on another antenna has shown that bending down the radials definitely improves Gain & SWR. The diagram above can be thought of as representing either voltage or current. Carefully read all of these instructions to get the best use from this meter. Antennas for this chunk of the rf spectrum tend to be modest and fairly cheap, especially if you design and build your own antenna from locally available materials. If this is true shorten both ends of the antenna in stages until the lowest SWR point is at the center frequency of the band or the frequency you will use it at the most. Pacific Antenna Easy SWR Indicator Kit Description Monitoring the match of an antenna to your transmitter or adjusting an antenna tuner for best match requires an indicator of the reflected power as an indication of how well the antenna is matched to the transmitter. The SWR-121-HF is a 32 MHz cable and antenna analyzer from AEA Technology. If channel - 40 SWR is higher than channel - 1 SWR, Lower the whip, or Lower the adjustment screw (Fiberglass antenna) Important: The main Idea when setting up your SWR is to have channels 1 & 40 the same and both typically have an SWR under 1. If chan-1 SWR is higher than channel-40 SWR, the antenna whip is to short and must be raised. This section of the site will show you how to use one correctly and tell you what to do to improve your readings if necessary. The 80 meter antenna is resonant at 3750 with the 130-foot length shown. HOW TO SOLVE YOUR ANTENNA MATCHING PROBLEMS. The SWR, or Standing Wave Ratio, is a measure of how well the impedance of the transmitter (or receiver) matches the impedance of the antenna system. Modernt radios with automatic antenna couplers will easily compensate for this higher SWR. Oh and don't get super hung up with low SWR. I'm going to enjoy this when I get back on the air. If the ohm of your transmitter and antenna do not match your SWR, energy may ricochet back and forth through the cable. The diagram above can be thought of as representing either voltage or current. Although it’s by no means the most important element of antenna performance, it’s the easiest to measure, and thus probably the parameter most talked about. Also, a high SWR (2. It is this low SWR that they know the unknowing will fall in love with. Remember the OCF dipole has an impedance of 200 to 300 Ohms so you will need a 4:1 or 6:1 BALUN if you do not use a remote auto-tuner. Under certain conditions a wide range antenna tuner may be required to obtain a lower SWR. If the low edge has the lower SWR the antenna is too long. how to reduce cb radio reflective power, reducing SWR in AC be set up, I am getting a high reflected on my cb antenna will a match box help, high reflect and low swr in mobile, how to lower rf reflected power, how to calabrate a swrant. After the antenna is mounted, read the SWR. ZS6BKW antenna is derived by the popular G5RV dipole antenna, but offer more bands a lower SWR on most bands and radiation angle making suitable for DX About The DXZone The DXZone is the largest human created and maintained library of web sites dedicated to Amateur Radio, currently lists 20. Saturday, June 23, 2018 How a simple counterpoise system can lower your SWR. The antenna SWR is calibrated at the back of the amplifier with the amplifier in line and turned off. Design Note DN024 SWRA227E Page 6 of 16 4. now it’s back to prove its legendary status once again! A Full-size radiator with lower radiation angle concentrates power closer to the ground, where you want it. So the SWR is a measurement of how much signal is going out the antenna, versus how much signal is reflected back into the transceiver. SWR is fantastic. SWR looks pretty good, but notice how the maximum SWR drops with frequency, compared to the EZNEC model of the antenna's SWR at the loop feedpoint: Could this measured "improvement" in SWR at high frequencies be due to feed-line loss?. A half-wavelength radiator has a high impedance (high voltage, low current) at the feedpoint. SWR (measured with an SWR meter) shows you how well your coax, antenna mount, ground plane and antenna match the output capability of your CB radio. After the antenna is away from sur-rounding objects, recheck the SWR to see if it has changed. HF Antenna Analyser With Arduino and DDS Module: HiIn this Instructable I'll show you how I built a low-cost antenna analyser which can measure an antenna and display its VSWR over any or all of the HF frequency bands. com: Gam3Gear SURECOM SW-33 Mark II 100 W 125-525 Mhz Mini Digital VHF UHF Two-Way Radio Handheld Power & SWR Meter: Home Audio & Theater. Many people use lower dipoles successfully on 160. You have determined that the SWR is lowest at 7. When you put your amp in line and check the SWR with it on high it should read slightly higher , no more then 1. I'm going to enjoy this when I get back on the air. The radia- tion resistance of a horizontal dipole can. When checking the SWR or the "Standing Wave Ratio", you will be hooking up a simple form of a directional watt meter between your antenna and the CB radio. If the whip is fully lowered into mast and the SWR is still high, remove the whip from mast. This is assuming direct transformation of the antenna's complex impedance to 50 ohms. However it is found that if the coax feeder can withstand the higher voltages and current as a result of the poor antenna match, and the feeder loss is not too high, then the system will work well. You can read coax cable loss in dB and match efficiency. Get 75 ft of rg-213 and you will see a change. Re: End fed antenna - length and SWR Hi Dave, If you want to check in with anyone in Oregon you may want to change the orientation of your antenna. Thus, a better match of the antenna to the feed line, that is, a lower SWR, becomes increasingly important with increasing frequency, even if the transmitter is able to accommodate the impedance seen (or an antenna tuner is used between the transmitter and feed line). Trimming the length of your coax will trick your SWR meter and you in to believing your SWR is lower. If it is too long don’t cut it – just fold the ends back on themselves and either twist the wires. Considering the coaxial cable losses, and the fact that even when using a tuner between the radio and the coaxial cable antenna feeder, the SWR in the feeder will still be high, undue stress can be caused to the coaxial cable due to SWR-induced high voltage and current nodes within the cable. 1:1 VSWR seems to be the "holy grail" of SWR, and I really have no idea why there is such an obsession. Getting the SWR right is crucial not just for getting decent range but also because a high SWR reading can damage your CB. This unit combines six basic parts: a variable oscillator, frequency counter, independent oscillator, 5. Many excellent examples are highlighted in Chapter 9 of the 21st Edition of the ARRL Antenna Book[1]. You tune the antenna as mentioned before then set a "baseline" FS reading at a set distance. When you put your amp in line and check the SWR with it on high it should read slightly higher , no more then 1. If you have a CB radio that isn't performing well it could be your SWR reading. If you couldn’t get the SWR down to 1:1, try connecting the antenna tuner/radio to the other BNC connector and repeat the previous step. My previous simulations on another antenna has shown that bending down the radials definitely improves Gain & SWR. We broke our list of common high SWR causes into six primary categories. My name is Michael, KB9VBR, and I carry a full line of VHF and UHF antennas for sale. If an SWR reading at the low frequency end of an amateur band is 5:1, decreasing to 2. The MFJ-945D will reduce the SWR of most antenna systems to 1:1. You have measured the SWR of your 40 meter dipole at various frequencies across the band. You must know how to tune a CB antenna by changing its length. 5 SWR is the acceptable range with the lower number being the best but not always obtainable. The antenna works just fine for me since 2M is my preference, but if optimum performance on 70cm is necessary, a separate ¼ wave dipole for 70 cm would yield lower SWR across the whole band. You can adjust UHF dipoles, verticals, yagis, quads and other antennas and determine their SWR, resonant frequency and bandwidth. The operating bandwidth is also marginally higher for a given acceptable feedline VSWR. I have seen the ends of a dipole antenna arc,spark and cause a fire. Reprinted from Echelford Amateur Radio Society Newsletter for November 1978. Most antennas are based on a dipole, Yagi's use a dipole antenna as the radiating element, vertical half wave antennas are "end-fed" dipole antenna. 80m Wideband Dipole Antenna Requirements. This unit combines six basic parts: a variable oscillator, frequency counter, independent oscillator, 5. Connect the antenna (normally connected to the back of the CB ) to the connector marked "Antenna" or "Ant" on your SWR Meter. A DOUBLE BAZOOKA antenna is an extremely broad banded Half Wave Antenna which can operate efficiently across an entire Ham band with little change to the SWR. Interactions in the worst case ruin patterns, kill gain and screw up SWR. 80m Wideband Dipole Antenna Requirements. 3 dBi with a 1. Thicker wire means a few things such as less loss and lower RF resistance (which. The 80 meter inverted vee is a common and classic antenna. For use 40-10m the antenna is acceptable as is. any help is appreciated. The adjustments you make based on this information will depend on the type of antenna you are adjusting: Whips, Mobiles and Groundplanes. So goes antenna systems. In his video Adam shows how he measures the SWR of an ADS-B antenna which he has built and is selling. The removal of these seals will expose a wire which is terminated to the end of the outside metal cover. This is the Hy-Gain model CLR-2 5/8 wave omni-directional ground plane antenna. 5-in is advised. MFJ-941B VERSA TUNER II INSTRUCTIONS Thank you very much for purchasing the MFJ-941B Versa Tuner II. If an SWR reading at the low frequency end of an amateur band is 5:1, decreasing to 2. Tune the antenna to put the center point for a two to one SWR at the correct location on the band to give me no less than one point five to one SWR at the bottom of all bands but 80 Meters. Clicking this. Re: End fed antenna - length and SWR Hi Dave, If you want to check in with anyone in Oregon you may want to change the orientation of your antenna. 000 000 MHz STOP CHI. A 12 volt bench power supply used for testing will produce different results than a 13. A quarter wave works better than a random wave antenna because of harmonics, I think that's the right word. The antenna lead from the tuner "longwire" terminal to the antenna should parallel and be reasonably close to the outside ground lead, if possible. If you are alone you are gonna have to test swr, open the door, twist the knob, then get back in and try again. Installed 6M Cushcraft Ringo AR-6 Vertical I notice my AT600ProoII tuner can only tune the Endfed on 6m band at aprox. Can be multiband with traps. If you have a CB radio that isn't performing well it could be your SWR reading. By mounting the antenna on a 2M quarter wave counterpoise made from 2 speaker wires, he was able to drop his SWR below 1:3:1 for the frequency range of 50-54 MHz. This is a CB and Ham radio dealer located in Bergen. 1 3 Calibrate for SWR (Standing Wave Ratio) SWR calibration is done to properly adjust the length of the antenna and to monitor the. Description:AW07A antenna analyzer is a compact battery powered RF impedance analyzer. There are many things other than the antenna that can cause high SWR. This 3 to 1 “Standing Wave Ratio” is a polite way of saying “loss. •If the Impedance is 50 ohms but, the SWR is not 1.