Coax phasing harness. This is important for a good SWR.

Coax phasing harness I usually seal the point where the coax splits and all the braid with black RTV sealant. Phasing harnesses for 2 or 4 antennas are available for up to 15 dB of gain. BOOM SECTION REINFORCING SECTION COUPLER STEP 2 BOOM ASSEMBLY MBSK You seal job looks fine. have been in search of lasting over 2 years mostly online research for this tiny bit of information about making my own coax harness for a dual antenna setup for 11 meter that apparently cannot be shared by anyone or maybe a big coax manufacturing company for dual 2-Stack UHF Phasing Harnesses. The first thing is measure the phasing harness for length before you start. Phasing Harness The phasing harness I used consists of 6 pieces of RG-59 coax. If the coax is an exact odd multiple of 1/4-wavelength electrically (after accounting for the coax propagation velocity factor) the RF reflected back from the antenna will be exactly out of phase with the transmitted signal, and the SWR meter won't "see" it, which causes the meter to give an The power splitting/combining is achieved through the use of two lengths of coaxial cable whose characteristic impedance is defined by: Zo = square root (2) x Z Clearly for use as a phasing harness it is not possible to place a 100 Ohm resistor on the outputs as the 6M beams need to be stacked at least 12 feet apart. Martin, OK2FKF has stacked his 2x7-El. Note: With this array type Feed2EL does not find a solution with 50 or 75 ohm coax delay lines. Suddenly one day you notice that the coverage has gone crazy, and it's most noticeable on weak (i. Remember to confirm the velocity factor for the coax you choose. A standard OAL Wheel is made for a left hand bend looking downward from the common feed point side of the coax jack. 66 for solid polyethylene dielectric RG213 and equivalents (rotation loops), and 0. Second, I have some DB Products folded dipole elements and made a simple coax power divider harness using 75 ohm TV coax that matches four 50 ohm things to one 50 ohm thing and tuned it to around 155MHz then installed my dipoles on I've been designing a "Super J-Pole" for 10M in MMANA-GAL, but I'm designing it having two 5/8λ sections. Phasing Harness, for Two Mono-Band Beam Antennas, works for 2m or 70cm bands, UHF Female Common to 2 Equal Length Coax Cables w/UHF Male, Each Aluminum Tubing Coaxial, 3 kW, 50 ohm, N female, Each. To do this, each leg of the harness needs to be 1/4λ (or odd multiple of a 1/4λ) long of 75 ohm coax. D. However, I came across this picture: Various J-Poles types diagram indicating the phasing stub for a colinear 5/8λ Right now I'm leaning towards joining the equal lengths of 300Ω twinlead at a common point connected directly to the coax. R. I picked up some RG62 92ohm coax. There are no reviews for this product. prcguy . The harness for the co-phase setup is a typical RG-59 A/U with the twin cable connector on one end. It explains that coaxial connectors and equal length phasing lines are needed, with the phasing lines being odd multiples of a By mounting the Co-Phasing Package unit on the tower and connecting up the two antennas using the attached coax harness with its jumpers to the two antennas (a wideband discone and an 800 MHz yagi aimed at southern Rhode Island), the Ham was able to receive both the high-band and 800 MHz systems perfectly on a single scanner. After the first ¼ wavelength, impedance doubles itself and repeats itself every ½ wavelength. $6. 873 Mhz and trim the coax until you see minimum Z impedance. 75 wavelength pieces of coax to build a Co-Phasing Harness - Two Antennas Super-charge your reception by feeding your scanner with a wideband and/or multiple band-specific gain antennas! type of wideband scanner antenna by allowing you to add multiple antennas to your mast and feeding them with a single coax line. You may adapt it to a 2 element system easily with the 90 degree phase shift section and a relay. Note that the RG-59 center is just used as the gamma match. The elements can not be separated by the "rule of thumb" 1/4 wave as the elements would overlap with each (land on top) of each other because of the optimised Co-Phasing Co-phasing or “stacking” has long been a way to get high gain from antennas. This document provides instructions for building a stacking harness to combine two 50 ohm antennas. From: NO4P Sent: Wednesday, January 13, 2021 9:48 AM To: main@Ham-Antennas. It takes some experimenting to implement - the "on line help" is not that self explanatory. As a “fun” note, the tuned cable lengths were used extensively in the TV - to change over from 300 ohm symmetrical to 75 ohm asymmetrical. So if we phase our array with parallel feeder made with 14 AWG THHN wire the length of the phasing line is 19. By mounting the Co-Phasing Package unit on the tower and connecting up the two antennas using the attached coax harness with its jumpers to the two antennas (a wideband discone and an 800 MHz yagi aimed at southern Rhode Island), the Ham was able to receive both the high-band and 800 MHz systems perfectly on a single scanner. Dual CB Coax Co-Phasing Harness with PL259 x 3 ProComm Dual Coax Cable Assemblies best known for their hi-performance and quality. It seems to me that SW was correct about adding odd but same length 50 Ohm coax between the 75 Ohm harness and the antennas. This would be compounded by the restraints of phasing harness coax lengths. Picture at Czech VKV activity 10/07 in JO70UQ in 1370m ASL. 09 FT. Feed the dipole with 50 ohm coax unless you are building a phasing harness for multiple dipoles (detail of the harness is not given here but it is a common "odd quarter wave" matching harness). It is weatherproofed in the field. I finally completed the harness for 2 Maco 103c vertically stacked 27. 5-108 MHz, specify 10%, N-type input/outputs, 500W The co-phasing harness is a 50 ohm power splitter and the coax lengths are critical for matching. Most dual CB antennas are sold with a 75 ohm coax "phasing harness" that is simply a power divider that matches the two 50 ohm antennas to the 50 ohm radio. Rotor Cable. Times Microwave Systems: Product # Model # Description: Price* 1006837: Genuine Times Microwave! LMR400: FLEXIBLE LOW-LOSS COMMUNICATIONS COAX $ 1. The phasing harness sections are strapped to each dipole, minimizing feedline coupling and pattern distortion. a manufacturer's spec for all coax cable, usually 66% for most low-mid priced 50Ω coax, about 75% - 81% for 75Ω) Yes, but it is part of the phasing harness so is definitely part of the final system. There are several ways you can construct a phasing harness. See Co-phasing harness coax formula for type of coax to be used (below). Question: Why do most mobile antenna makers recommend 18 feet of coax? Answer: You got me, they claim you should use 1/2 wavelength multiples of coax. If you want to match anything else it could take 1/8 wave or 1/4 wave or something else or the mismatch may not be able to be fixed using this method. Not Yet Reviewed. Good antennas, good coax (phasing harness), and good install, should give good SWR. About Us; General Info; Shipping Methods The phase harness is located directly at the antenna and consists of various coaxial lengths with varying impedances; thus the harness is responsible for the correct phase difference of the polarization planes and matches the system to meet the 50 Ω impedance of the feed line (remark: just one feed line is required). The pattern would look like this – 50 ohms, 100 ohms, 50 Coax / Cable. Starting off with the distance you should use, let me discuss what good stacking distances are. WiMo Big Wheel Horizontal Loop Antennas 18007 Your phasing harness presumably has the one-quarter wavelength lengths of (probably) 75-ohm coaxial cables to transform each 50-ohm antenna up to about 100-ohms for paralleling, resulting in a 50-ohm array. This would be a coax jumper that is 1/4 wavelength long, taking into account velocity factor of the coax and any offset between the horizontal and vertical elements. Connectors 9' Co-Phasing Harness W/PL-259 Ends. After installation of the Firestik coax the SWR dropped to less than 1 , almost perfect > It's not about isolation (and obviously, when you're talking about > using coax inside an antenna, isolation isn't a concern). The two items of coax I had to specifically reduce are classified as "Phasing Harness": So what I had on hand was Belden 8237 RG-8-U Kind coax. Several times a year we get tech calls from installers who place dual antennas on their vehicle and run RG-58 or RG-8X from each antenna to a T-connector at the back of their radio only to find that the system "doesn't get out". 100 ohm, 37. Phasing harness degredation - from water ingress, old UV-damaged coax, or physically damaged coax is best explained by this: Picture four loop dipoles side mounted on a steel mast at the top of a tower. J. I've always been satisfied with the quality of their work, and Length does get critical with multi antenna where phasing comes into play. Coax. The same rule applies in that you will loose 3dB of gain in the linear polarity but talking to another circular polarity antenna you will gain 3dB over using a linear pol antenna. About Us; General Info; Shipping Methods Buy Firestik Antenna FireStik MU9R18 18-Foot 3-Piece EZ-Install Co-phasing Harness: Radio Antennas - Amazon. You really need a antenna analyzer to get it right and if you target the center frequency of a repeater pair it works fine because the BW of the coax phasing harness will be wide enough. I decided a complete change was needed. Commercial whips seem to utilise a single wire as the radiating element with . 95 INCLUDE Add Items To Cart. Dual antennas use a co-phasing harness that has to be a specific length and impedance to get the 50 The SS770R is a Phasing Harness that allows you to phase together your beam antennas along with the SB144 and SB430. Coax Wrap Roll - Red - 1 Inch Wide by 10 Feet Long. Yea, I have installed a few antennas, base, mobile, semi with duals and had so little reflected power, my meter barely showed it. COAX-SEAL. The velocity factor of 50 Ohm coax is typically 66 or 85. Information. Phasing Harness Calulator for 71 and 84 degrees All you need is the target frequency and velocity factor for this one. (1/4 wavelength) co-phasing will do nothing for you. The Ultimate Guide to 11 Meter CB Antennas states correctly about the 90 degree phasing harness, however the choice of cable will make or break the operation. ReceiverBeaver Completely Banned for the Greater Good. e. -28Ohm-group with this principle. 31 This is because proper phasing is involved and that does not happen as a lark with some random length of coax that will reach to the points you want. 66 velocity factor phasing shields along the radiator with no other connections. The two pieces of coax I had to precisely cut are labeled “Phasing Harness“: So what I had on hand was Belden 8237 RG-8-U Type coax. g. I included The errors are basically caused by the extra and/or unequal lengths of coax that are operating at an SWR >1. To use a second standard Wheel, but have the coax connectors face each other on the mast, you need to DH18N13 - ProComm 18' Co-Phase Harness With Fme Connectors. Note that the loops are both orientated in the same direction as described in the previous paragraph. Joined Feb 11, 2017 Messages 186. A26B2 antennas offer the highest gain of any 2 meter FM antenna. PL-259 connectors on each end of RG8 cable. In addition to 9. Joined Nov 20, 2004 Instead of a critical length 75 ohm phasing harness to combine the antennas you can use a good 2-way 50 ohm power divider and two coax jumpers of any length as long as they are exactly the same length. Thanks. Grounding Kit. The 50 ohm and 75 ohm cable is joined together for each "dip-yag". 73 Phasing Harness 6M Yagi Options: 2 x 8. The branches are terminated with N Female coaxial connectors, while the feeder end is equipped with an N Male coaxial connector N(m-4. F. It's > about the noise problems associated with bare copper braid > cables and cables with dissimilar metals comprising the shield. 29 feet the 17. For critical applications, there would be better types of The antennas are expected to be 50 ohm, the phasing harness is made of 75 ohm coax of a specific length and the end result is it becomes a 50 ohm power divider for a 50 ohm radio to feed two 50 ohm antennas. Technical Data. Joined Dec 25, 2009 Messages 412 Find Diamond Antenna Phasing Harnesses and get Free Shipping on Most Orders Over $99 at DX Engineering! Diamond Antenna Phasing Harnesses provide 2-port phased power division. Sure, you can phase together multiple identical antennas for a narrow frequency band but the practicalities of it are pretty difficult without vector voltmeters and line stretchers. However, if using economy coax, your quoted VC may be off, so if that’s the case, you may want to measure a 90 For making a phasing harness to match two 50 ohms antennas to a 50 ohm its already figured out. Feed Provider. You now have a Just for information, first of all get rid of that CB term "phasing harness" to avoid confusion. It will be fine for regular antenna feed line use if it is short, but I would trade it for LMR400 if I could. Since we are dealing with coax cable these calculations need to include the velocity factor to You do not have to use 18', keep both sides even to a T connector with 75ohm coax and then 50 ohm coax to the radio or a 75 ohm co-phase harness that reaches the antenna it will make it's 50 ohm connection at the radio, short is more gooder. Estimated Ship Date: Jan 29, 2025 if ordered today. 89 or 0. Scroll down on the link to find the pdf instructions. You would have more loss in the phasing harnesses than you would gain. Two Big Wheel antennas vertically stacked will achieve about 5 dBd gain with a monoband power divider or coaxial phasing harness that connects two same-band antennas to one coax feedline. 039 ft or 1. The velocity factors are those for the types of coax to be used. A classical 4 Yagi stack may be fed and phased using 50 ohms coax efficiently when using odd multiples of λ/4 like 5/4 λ for making the horizontal phasing lines. By using our site you consent cookies. I make no claim for this working as intended on the big truck, but your phasing harness does not need to be 18' feet long, unless you need the added length to reach. The exact length of the cable is important as it's a Cut the coax to the suggested length plus a few inches, in case your velocity factor is not quite right. 2 Yagis, 2 coax and A/B switch is how it must be done. Brad Then how does the DB-404 work? It consists of 4 folded dipoles which are combined by what appears to be a phasing harness. Stacking Harness Feeding two 50 ohm antennas requires a harness to divide the power between the two antennas and also to maintain a 50 ohm system. The only way this optimised yagi can be crossed polarized is by placing the elements adjacent as I built. The coax option should not be difficult or particularly expensive to do, but The harness consists of 2 lengths of 75 ohm coax, 1 length of50 ohm coax, hand-soldered PL-259 connectors, T connector,barrel connector, and sili. 5' apart. CB antennas can not be expected to perform to their maximum potential if the coaxial cable is unable to deliver what the radio has to offer As with all of our cable assemblies, you are quality assured The 71-degree phasing line should be: 6. 5 ohm coax, to bring it back to 50 ohms. Rv! Geoff 2004-01-22 13:11:47 UTC. You cannot use TV splitters, you must use a T connector or even solder three junctions of coax together. The design provides an easy to build high gain antenna for repeater use. 66 and a characteristic impedance of 52 ohms. That is to say that your mechanical spacing is 105 degrees so you need to remove 15 degrees from the Description. The 71-degree phasing line is 90 degrees at 26. 66 and also a particular impedance of 52 ohms. It's far better to build the rest of the phasing harness in 50 ohm coax operating under matched conditions, and use the shortest possible divider, either 0. The power splitting/combining is achieved through the use of two lengths of coaxial cable whose characteristic impedance is defined by: Zo = square root (2) x Z Clearly for use as a phasing harness it is not possible to place a 100 You should duplicate the elements, element spacing, connector placement and wires to the elements, coax phasing harness length and height above the screen exactally as the instructions. Various: Product # Model # COAX: Any of these should be just fine. x N-Type connectors at the antenna end (one for each driven element) and an N-Type female connector to attach your main coax feed to. iceman977th Member. 75m + 1 x 8. 873 Mhz. Murphy625 Member. 88 = 17. For critical applications, there would be better types of You will need a 75ohm phasing harness (RG59 works fine) to connect your Wilsons in a phased array. Second, with a 4 antenna array it's going to be very difficult to achieve proper phasing over the entire UHF band. For use with the 18010 144MHx X-Quad to convert to right hand circular polarization (RHCP) 2 x N-Type connectors at the antenna end (one for each driven element) and an N-Type female connector to attach your main coax feed to. If you want a phasing harness for a band different than CB then its dimensions will be different. This antenna appears to combine a 2m and 70cm yagi on the same boom, each You must use 75ohm coax for the phasing harness. The harness can be extended if needed, but that is another issue. But in practice at 27MHz, w A phasing harness is basically (2) sections of 75-ohm cable cut to odd quarter wavelengths X velocity factor, transitioning to a 50-ohm cable, which is usually the transmission line. Top of Antenna Bottom of Antenna Authored by Doug Zastrow, WBØUPJ Coax Cable: Belden: Product # Model # Description: Price* 1006322: Genuine Belden! RG-8U (9913F7) THE NEW FLEXIBLE RG-8/U 100%: $ 1. Remember the formula you used is for a 1/2 wavelength, but in the math we fold the wire in half to make the harness Coax has a velocity factor that affects how long electrically a physical length of wire appears to RF. Cut the coax to the suggested length plus a few inches, in case your velocity factor is not quite right. By selecting the right lengths of delay / phase lines, we can skew our energy toward Anyone got a design for a 2m 2 port phasing harness around? I want to build a two way Yagi splitter and just can 't find my old information, so all help appreciated. 18 feet isn't even close to being a 1/2 wavelength in any 50 Ohm coax you will find. l. 5m) Leads w/ FireRing Connectors and Mini-UHF Section Connectors the antennas can not be expected to perform to their maximum potential if the coaxial cable is unable to deliver what the radio has to offer. Heliax VF is 0. The length of coax between the antenna and the coaxial T connector needs to be the same on all antennas, but is not a frequency dependent say 3/4 or 1 1/4 wavelength, which would be the case if 72 ohm coax was used. This is a picture of the stacking A better idea, given construction tolerances, is to first bring the two antenna coax cables together to form a 25 ohm feedpoint, and then use a parallel pair of quarter-wave 75 ohm cables which form a 37. Show Less. This can be done with a M. " then they weren't phasing harnesses. Co-phasing involves placing two (or more!) identical antennas either side-by-side or one over top another (“stacking”) at a certain distance apart (usually a 1/2 Wavelength or more) and feeding the antennas Your phasing harness presumably has the one-quarter wavelength lengths of (probably) 75-ohm coaxial cables to transform each 50-ohm antenna up to about 100-ohms for paralleling, resulting in a 50-ohm array. This is important for a good SWR. So, we see that SW is right, we can use a random length for our harness, and we can even use 50 ohm coax, without a phasing harness, but we won't get a workable tune. No 50ohm coax required. $4. Cushcraft Power Divider Harnesses. The slower velocity makes the cables shorter and makes for a more compact phasing harness for any duplexer or phased combiner assembly. Mar 28, 2010 coax under headliner through vent to > It's not about isolation (and obviously, when you're talking about > using coax inside an antenna, isolation isn't a concern). Part Number: DMN-SS770R. It could help on a few co-located channels and maybe Connect this piece of coax, called a “phasing harness” across the first fed dipole, in parallel with the connection to the feed coax. A co-phase harness is 72 ohms before it splits into 50 ohms for each antenna. Coax Seal. Today I completed this VHF 4-bay dipole array but not before putting the 17. 25 wl or 0. Feeding from one side of the coax will give you left hand circular, and UNV104 Malleable Plastic Material for Sealing Coaxial Cable Connectors. Two cables l1 and l2 with any but same length of 50Ohm coax will give a Z=50Ohm at the connection point. In a co-phased harness, impedance repeats itself every ½ wavelength. The basis for the myth is a quirk in the way SWR meters work. He would like to add a secound phasing harness but would like to keep the single feed line. Connectors 18' Co-Phasing Harness W/PL259 Ends. To connect two antennas to one coax feed a usual phasing harness can be used. io Subject: [Ham-Antennas] Feedline harness for combining antennas for different bands on one feedline. Just buy two yagis, two coax cables, and an antenna switch. That will present something close to a 50ohm impedance to your radio. And the coax in the Their new UltraMatch balanced feed provides a reliable 50 ohm match via a standard SO-239 UHF female connector. Higher gain or a special shape radiation pattern is achieved. One piece of lambda/4-75Ohm-cables will give the 50Ohm for the feeding. Ordering options cover 66-470 MHz. 95 INCLUDE CW10R The two pieces of coax I had to precisely cut are labeled “Phasing Harness“: So what I had on hand was Belden 8237 RG-8-U Type coax. Write a review Previously we wrote about the woes of being a northern amateur, and how the phasing harness for our 2 m station had broken due to a coaxial cable with too low temperature rating. Figure 1 – Special harness to produce Circular Polarization. If you were to make the phasing harness out of 50 ohm coax the results would vary a little depending on coax length but in general you Textbook colinear vertical antenna designs show coax cable with alternating braid to centre configuration. If you feed two omnidirectional antennas (to keep things simple) in phase, that is with two equal lengths of coax and they're 1/4 wave apart the result will be an end fire array, a figure 8 I've seen many times how you make a co-phasing harness for 2 antennas (for example, an SO-239 "tee" to two odd*λ/4 lengths of 75Ω coax), but I'm having a hard time finding information about how these stacks of 4 (or sometimes Co-Phase Coax. Don't use different pieces, or brands, of cable for the phasing lines, as different cables may have slightly different velocity factors, which can The antenna is the biggest factor in any radio system with the coax the second, trust the science. FM Radio 2-way Yagi phasing harness, 87. Coaxial delay line(s) is the proper term, let me explain. I am intrigued by the feedline T-harness used on the Cushcraft A27010S. 5ft Diamond X510 clone, taking some precise receive measurements and find the new VHF 4-Bay dipole The length of coax between the antenna and the coaxial T connector needs to be the same on all antennas, but is not a frequency dependent say 3/4 or 1 1/4 wavelength, which would be the case if 72 ohm I am currently using a two stack arrangement with the following phasing harness measurements. More planning than anything. 841 m. This picture shows the completed assembly prior to building the phasing harness. Leaving one end of the coax open, set your RF analyzer to 26. M. 66 or 36ft x 0. If you need to extend a factory harness its best to add 50 ohm coax to the center common point or to extend the two antenna sides with equal lengths of 50 ohm coax since the harness is designed to provide a 50 ohm match where each antenna usually The 492 and 493 are light duty, the 498 is heavy duty. 2-way VHF Yagi coaxial phasing harness, 148-174 MHz, specify 10%, N-type input/output, 500W PDY32 4-way VHF high band Yagi coaxial phasing harness, 148-174 MHz, specify 10%, N-type input/output, 500W If a 180 degree phase change is desired, I would think there would be less losses in a transformer like you mentioned than in a phasing harness using coax. The factory coax was over $30 per section X 6= $180+ . The phase harness is located directly at the antenna and consists of various coaxial lengths with varying impedances; thus the harness is responsible for the correct phase difference of the polarization planes and matches the system to meet the 50 Ω impedance of the feed line (remark: just one feed line is required). The antenna design in the article proposes using a T-connector with a 22" length of coax going to one antenna and a 16" length of coax going to the other antenna to (supposedly) achieve 135-degrees of phase separation. Fig 2 shows such a coaxial implementation from (King et al, 1945) Fig 22. Dual CB Coax Co-Phasing Harness with PL259 x 3 ? ProComm Dual Coax Cable Assemblies best known for their hi-performance and quality. First off, stacking takes a lot of planning, time and money. The A26B2s include two complete A13B2 antennas, a stacking boom, and a phasing harness. You can use 75 ohm coax to feed the entire antenna if you don't mind the additional loss Either ScannerMaster or the "extra class ham" that is making it has no clue what a co-phasing harness is or how to use one. Filter Results Results 1 - 3 of 3 25 Records Per Page Default Sort . It is 0. An example: At a given stacking distance of 3. Cushcraft 2 Meter Power Dividers are key elements in phasing or "stacking" Cushcraft "Boomer" 2 meter antennas. STEP 1 iao” 4> 2” O. Just add equal lengths of 50 ohm coax between the divider and each of the antenna feed points. In the main, we use phase lines to split power to more than one antenna. I mentioned the Dividerless phasing harness in the beginning; let me explain. 75 or 50 ohm coax ohm in parallel with the cores joined) will find a solution for coax lines, the series matching finds a solution with 25 ohm, so it would be possible to feed and match this array type using 50 ohm coax Coax / Cable. 84 for the foamed PE found in variants of LMR400. Radiating ‘Leaky feeder’ cable; 1-5/8″ corrugated shielded cable; 1/2″ corrugated shielded cable; 1/2″ super flexible helical shielded cable; RU600 low loss solid core; RU400 low loss solid core; RG214 dual braid shielded; RG213 This is the computation for the length of phasing harness required to any frequency computed from antenna center frequency that you are stacking . These 4-Stack UHF Phasing Harnesses combine four antennas to ensure they are in sync, maintaining a low standing wave ratio (SWR) and minimal signal loss. prcguy Member. 95 INCLUDE CW10B. As with all of our cable assemblies, we are as picky with what lies between the connectors as we are Typically you would harness them together with a phasing harness. sections transform the Z of the antenna as presented to the main feed line and while the ‘Traditional’ Circular Phasing Harness Modifying the Phasing Harness. If its a great match near 50 ohms then you can easily make a phasing harness to feed two or four dipoles out of 75 ohm coax and F connectors and F "T" adapters. Good quality RG-8/U coaxial cable is . 0 out of 5 stars ( 1 ) This generally uses 75 ohm coax at specific lengths between the two antennas and 50 ohm coax (if needed) between the junction of those two parts of the phasing harness and your radio. Leaving one end of the coax open, set your RF analyzer to Mhz and trim the coax until you see minimum Z impedance (alternatively, you can also look for minimum X reactance). Some designs use . This has a rate variable of 0. Diamond Antenna Phasing Harnesses SS770R DMN-SS770R. SWR meter or similiar device. For high elevation sites near the target area, one-half of the array can be used to provide less By mounting the Co-Phasing Package unit on the tower and connecting up the two antennas using the attached coax harness with its jumpers to the two antennas (a wideband discone and an 800 MHz yagi aimed at southern Rhode Island), the Ham was able to receive both the high-band and 800 MHz systems perfectly on a single scanner. I am assuming that the phasing harness is 1/4 wl (velocity factor corrected length) and if that length is not enough to span the distance and leave enough for the choke then you could make the phasing harness 3/4 wl (v. PHASING HARNESS FOR STACKING: Phasing Harness layout 2 X 1. ABS pipe was my first choice since it was on hand but the PVC looks like a good alternative, I always Using 50 ohm coax between antennas and co-phase harness Shockwave, I thought everyone might appreciate some feedback from this project. Any length of RG8 or RG58 may be connected to the phasing harness. Part Number: MSQ-70CM2PRTPD. If it is desirable to stack a pair of like antennas that have a 50 ohm terminal impedance and require on the order of 5/8 wavelength spacing this scheme works well. In the photos the construction side of the mast. Diamond Antenna Phasing Harnesses. SO-239 Feed Point. ? CB antennas can not be expected to perform to their maximum potential if the Phasing line calculation 1) Impedance : After calculation, the impedance of the phasing line section is 100 ohms. Testing found communication ranges of up to 15 miles. Phasing harness for 18011 432 Mhz X-Quad antennas Converts to Right Hand Circular Polarisation (RHCP) N-Connectors. I would also dxHome. Instruction Sheets for Part Number WMO-18008. RG-63/U (125 ohm) is easier to find but causes more of a mismatch when used with a 50 ohm main transmission line. RG-6 works fine and RG-11 has lower loss. The length of the RG-142 B/U coax between the cavities should be an electrical quarter wavelength, as should the length between the cavities and the T-connector. When you make the coax phasing harness, be make sure that your cable lengths are well matched, so there's no phase errors, and use the same piece of cable as the source for cutting each phasing line. 400-440 mhz or 800-880) tops before the setup starts to suck. High quality RG59 cable available in a 12 or 18 foot lengths the ProComm Dual CB Antenna Coax includes 2 nipple to UHF adapters for ease of cable routing. I have and still do see allot of people wasting money and being unhappy with system performance over bad antenna selection. f. ProComm 18 Ft. 34 m = 1. groups. 5-108MHz, specify 10MHz, 90° phase shift one arm, N-type input/outputs, 500W PDY-52CP 2-way FM Radio Yagi antenna coaxial phasing harness, suits FM Yagi antenna, 87. 29 FT. Pre-made harnesses available, no "T" required, easy peasy. This coax must be 75 ohm line; Belden 8213, RG-11, RG-6, Cable TV slick side, aluminum jacketed The explanation of the phasing sections as pure differential TL stubs is sometimes used to suggest a coaxial collinear form of the phasing section. Placing it at the point where the feed line attaches to the phasing You would use a phasing harness with one leg 1/4 wavelength longer in coax plus velocity factor or use a high power divider with one coax 1/4 wavelength longer. handheld) signals. Premium Subscriber. 31 feet. So with 50 ohms into each T connector, the output impedance is 25 ohms from each T. Phasing Harness, for Two Mono-Band Beam Antennas, works for 2m or 70cm bands, UHF Female Common to 2 Equal Length Coax Cables w/UHF Male, Each Part Number: DMN-SS770R 5. The length of the RG-142 or RG-400 coax between the cavities should be an electrical quarter wavelength, as should the length between the cavities and the T-connector. 81. The Maco Circular Polarization Harness is for users who wish toachieve circular The phase harness is located directly at the antenna and consists of various coaxial lengths with varying impedances; thus the harness is responsible for the correct phase difference of the polarization planes and matches the system to meet the 50 Ω impedance of the feed line (remark: just one feed line is required). Their PD-2 divider allows power to be connected to two Yagis simultaneously. Banned. (King et al, 1945) notes "their operation is, however, much less satisfactory than with the open wire stubs". SS770R Phasing Harness for Stacking. They are designed for stacking two 2-meter or two 70-cm beams. Dick, WA6MDI, has a Icom 9700 with the single Cushcraft A270-10s. When you connect your feed line to the SO-239 (UHF female) center, it then provides two outgoing cables terminated in PL "The phasing harness is made with an odd number of 1/4 wave-lengths of 75 Ohm coax to each antenna from the centre feed point (' T '), allowing for the velocity factor (vf) of the coax not just the free air wave length. Two-Stack UHF Phasing Harnesses harnesses are used to couple two antennas together so they are fed in phase, keeping a low SWR and minimum insertion loss. As a result, you must remove the indicated length from the coax feeding the leading DE in order to achieve an overall 90 degree phase shift . f). And then I realized I failed to ask how do I electricaly This setup showed >2. The harness that I have constructed work well and they end up being very short, like 6' - 7 ' in total span using 102" whips only. 0:1 SWR on my radio and the radio's cut-back was working, so I switched on my auto-tuner to take care of the mismatch. UNV104 Malleable Plastic Material for Sealing Coaxial Cable Connectors. Belden Times Microwave CommScope Consolidate Wire Andrew Commscope TerraWave DX Engineering Don't know, never used them: I've purchased several pigtails, longer cables, and one pre-assembled phasing harness from MPD Digital over the years. New posts Search forums. How does this work? I can copy the design but am intrigued as to the theory I had asked about building a phasing harness for 3 yagis antenna. dxForums. Just consider you don't have to go the work of antenna adjustment that sometimes can be a headache. 3(b). Connect the remaining two terminals of the phasing harness to the second dipole (oriented at 90 degrees). 90, which I won't be using for phasing these stacks. The Harnesses are designed to be completely A coax phasing harness will not cover the BW but you could use a high quality 50ohm divider rated for the entire band since it would be receive only. Changing the length or type of coax in the phasing portion of your coax will ruin the phasing and cause serious issues with your signal. The cable is fitted with PL-259’s mated with an SO-239 barrel con-nector in the center. For best results, coax harness lengths should be verified electrically for length. 95 INCLUDE CW10R. (via spacing the yagis or delay line in the phasing harness) from the signal source. 7 m roughly on 144 MHz whe taking the v-factor for PE coax into account. Service. prcguy is dead on, you need to have resonant coax lengths in the phasing harness, and you've got maybe 5, maybe 10% bandwidth deviation (e. Factory 2-page data sheet on the DB-844H90E-XY directed dipole antenna 122 KB PDF file RG-223 is an RG58-sized coaxial cable that has a silver plated solid center conductor and double shielded silver plated A phasing harness built from 75 ohm coax is used to combine the signals in phase. Premade. These will be cut to length and combined once the phasing harness is built and installed. 85. Trying to combine a VHF, 700 and 800 Yagi using one will have losses from the method used and also frequency spill over between a 700 and 800MHz Yagi pointed in different directions but possibly both picking up the same Connect the phasing harness coaxial connectors to the gamma matches of your Maxi Beams. VQ3 Stacking Kit VQ3. But you'd still want two feeds for this. 7 dBi gain, each dipole is 50Ω, allowing the phasing harness to be built from readily available 75Ω coax. ( Phasing line section formula : Z0= √ (ZL x ZA) → √ (200x50) → √ 10000 = 100 Ω ) Therefore the phasing line section can be constructed with 50 ohm coaxial cable « RG-58 ». Home; About; Delivery; Contact; Linear Amp Amplifiers. A single coax is 50 ohms. I. ) and that would leave plenty to wind the choke. Coax Wrap Roll - Black - 1 Inch Wide by 10 Feet Long. 25 and . 36m 50 ohm RG58 co-ax cable 2 X 386mm 75 ohm Good TV co-ax cable. 1 MHz in this case). com FREE DELIVERY possible on eligible purchases. Also, for 50MHz, just You can calculate the length of 75 ohm coax with velocity factor needed to split a single 50 ohm feed to two 50 ohm antennas. Dont have details and dont know much either, but know this much that a “Phasing Harness But those coax lengths can be critically off, especially when their propagation speed is unknown exactly. Each piece of coax needs to be an odd multiple of a quarter wavelength for the frequency you built the antenna for (432. This has a velocity factor of 0. Coax / Cable . Now we are back with a blogpost I refurbished the dipoles, built a 24ft aluminum mast out of some decommissioned antennas and built a coax phasing harness out of 75ohm TV coax and F connector T adapters. c. The SS770R can be used on 2m and 70cm bands. The RG59AU CO-phase cable provides superior connectivity in your radio to dual antenna link. Just connect the harness and loops as per instructions and space 68" apart. 67 ft x . LMR400 or RG213 Coax Cable IMPORTANT NOTE! Phasing and matching harnesses can be used to combine multiple antennas into one output or to split antenna signals into multiple paths. Ground Wire. Phasing Harness, for Two Mono-Band Beam Antennas, works for 2m or 70cm bands, UHF Female Common to 2 Equal Length Coax Cables w/UHF Male, Each See More Specifications. Leaving one end of the coax open, set your RF analyzer to Mhz and trim the coax until The 71-degree phasing line is 90 degrees at Mhz Cut the coax to the suggested length plus a few inches, in case your velocity factor is not quite right. The electrical 'length' of the phasing lines will not be effected much by external factors. 2) Length ( VHF Eggbeater ) : But the problem is I only have 12ft per run, and I need more like 19ft. Its best to tune the elements individually using a length of 50 ohm coax with the exact same length pig tails that will be used on the phasing harness. Connectors. 25wl. 84" from the tip to tip of the cable (including connector). Cable Clamps, Clips & Sealants; Grounding Kits; Coaxial Cable RF. The SS770R is a Phasing Harness, that allows you to phase together your beam antennas along with the SB144 and SB430. Donald KX8K Here's the article I was talking about. Write a review Coaxial Cable & Cable Assemblies. 25+0. The quarter-wave transformer will work fine over a much larger bandwidth than a Yagi. Each individual dipole is tuned for 50 ohms and the common feed point for the entire antenna is 50 ohm but the phasing harness is all 75 ohm coax. Technical Data; Product Name: Big Wheel Antenna 50/144/433 MHz : Stacking 2m: 1300 mm : Antenna Type: Omni-directional Antenna : Design of antenna: Big Wheel : Mono-/Multiband DB224E Phasing Harness Detail Molded Cable Assembly About 3” up from the center splice assembly the cable is cut to permit antenna shipment in two halves. It has "a feature" called "stack". RG-133/U (95 ohm) is the best to use for the harness. Nov 11, 2018 #8 cmdrwill said: When cutting the coax phasing sections, get as close as you can by calculation. of 75 ohm coax on both sides of the harness starting with 1. The lengths of coax in the phasing harness is extremely frequency critcal too so joining two different antennas together with simple coax is doomed. You would solder it to other pieces of coax in the phasing harness. I used LMR 400 coax (I recommend if your run is longer than 50')and Coax Seal on the connectors and Tee after mounted and tested. Since the stacking height between the antennas is 12. If you try to connect two single coax lengths to a T connector for dual antennas, you may run into high SWR issues. The problem with the result of the online calculator you pictured is that your DE spacing is already greater than $\lambda$ /4 (~172 mm). A few years ago I purchased a pair of 2m horizontal loops with the phasing harness from a seller on eBay. Dual coax with easy route option. . Answer: 75 Ohm harnesses for Co-phasing is the only exception. 75m High End Coax (75 ohms) (unchanged polarity) 1 x 3. 75m High End Coax (75 ohms) (changed polarity) 2 or 4 connectors (PL or N Connectors) Mounting kit Included 1 x Stainless steel (type 316) mounting plate 2 x Galvanized steel U-bolt mast clamp (60/M8) 8 x Stainles Co-Phasing Harness : Dual 18ft (5. The antenna breaks down into portable bags for transport and assembly takes under two hours with 2-3 people. 0 m the 5/4 λ equals 5 x 0. Use physics or google to check that it is right or left hand circular polarized. Free Shipping; Special Order; Take a look at MMANA antenna modeling software. You can use SO-239 style T adapter and PL-259 connectors on RG-59 coax or L-Comm "All of the co-phasing harnesses I have ever seen have been made up of only standard 50ohm coax. Also note that there are still two coax feed lines, one from each antenna. Most text books say that the spacing between co-phased antennas should be at least 1 wavelength (36 feet!). Joined Jun 30, 2006 Messages 16,001 With that said, you can make a simple phasing harness from RG-59, RG-6 or RG-11 and I found using F type compression connectors and F type "T" adapters really simplifies the construction. I'll then use a current balun on the 75Ω coax. Modifying the Phasing Harness. 5 or 25 ohm (e. So an electrical half wave length for CB is actually 36ft x 0. The RG-6 cable I used had a We use cookie to improve your experience on our site. Each TV splitter has more than 3dB loss so two sets of them eat up all the gain of the antenna and then some. You can possibly space the dipole elements about 1/4 wavelength from the mast at 400MHz and they would be close to 1/8 wavelength at the low end which might cause the impedance to pull around and . Q-Match Coax (in feet) = 246 x [velocity factor] / Frequency (MHz). Get on 2 meters in a big way. Documentation Instructions. Check out my VHF dipole array project and the phasing harness shown there will work on a DB-224. Use a co-phase harness for dual antenna installations. And don't use cheap coax or connectors!! Reply. C80-00017. C80-00030. Tape the harness along the booms and down the mast. These coax’s to be made are not 50 ohm coax. KF5FUR Member. 5 out of 5 stars. A power divider or splitter used this way will not incur a 3dB loss because you are combining two identical antennas in phase. I would go with a standard phasing harness myself and use 50 ohm co-ax from the harness to the radio if more length is needed to reach. diqvrxz wjmw ejostuj fhusb uifiwk iqzds rjoe vxe mcm sodqgmy