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DX Engineering Yagi Antenna Hairpin Matching Systems
DX Engineering Yagi Antenna Hairpin Matching Systems are a convenient way to match the feed-point of a low-impedance Yagi design to 50 ohms. Then a 1:1 balun fed with 50-ohm coaxial cable may be used for optimal beam antenna performance and cancellation of RFI-causing common mode current. The DX Engineering Yagi Antenna Hairpin Matching Systems are balanced and easy to tune. They feature an upgraded electrical and mechanical design and are easily installed and tuned in as little as 10 minutes. They have enough capacity for almost any HF through 6 meter high performance Yagi design. Depending on your Yagi design, they include all of the hardware items that you need to match your Yagi antenna to a 50 ohm feed line -- without the need for drilling holes. If your Yagi does not have a split driven element (insulated from the boom), you will need to add the proper-size DX Engineering Insulated Boom-to-Element Bracket and DX Engineering Boom-to-Element Bracket Hardware Kit. Depending on the driven element diameter, you may also need DX Engineering Element Adapters. Different models cover most Yagi boom sizes and they are easily installed on the boom and fastened to the Yagi's split driven element with clamps. These same clamps may also be used for the balanced connections to the balun that handles the unbalanced coaxial cable. Hairpin Matching System Background: Many directly-fed Yagi antenna designs for HF and 50 MHz that are optimized for the best gain and front-to-back performance have feed-point impedances of approximately 20 to 25 Ohms, at resonance. Obviously, this will not allow a direct connection to a 50-ohm feedline without a serious mismatch (2:1 or more). There are various ways to match the driven element to the feed-line successfully; Gamma Match, T-Match, and the Hairpin (aka Beta Match) are favorites. The Gamma match is an outdated, unbalanced system that typically distorts the antenna radiation pattern. The T-match is basically two Gamma Match systems on either side of the boom, which may correct the imbalance, but is a mechanical nightmare and is difficult to tune correctly. In a superior-balanced Yagi feed system, the driven element must be insulated from the boom and it must be split at the boom so that the driven element halves are also insulated from each other, like a dipole. A balanced Yagi can make use of a balun for balanced distribution of RF currents and a proper, predictable radiation pattern. While the hairpin has been popular with radio operators for years, DX Engineering Yagi Antenna Hairpin Matching Systems improve on the classic design by using rods that are parallel to the boom. You can quickly match your Yagi antenna by repositioning the boom clamp and shorting bar along the boom and hairpin rods, so the antenna is easier to adjust for minimum SWR than conventional wire-loop hairpins. DX Engineering Yagi Antenna Hairpin Matching Systems also add rigidity, offer better protection against ice and wind, and add a professional appearance. Note: Whenever the DX Engineering "Documentation" tab is available, please look at the associated files for additional product information. Improve your Yagi feed-point matching with DX Engineering Yagi Antenna Hairpin Matching Systems and accessories!
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$71.99
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$87.99
DX Engineering Mast Top Mounting Plate
DX Engineering Mast Top Mounting Plate DXE-MTMP is a multi-purpose 16 x 5.1 inch (406.4 x 129.5mm) aluminum plate, 0.25 inch (6.35mm) thick, with a long edge flange bend 1.5 inch (38mm) deep for reinforcement. It is drilled for specific DX Engineering Stainless Steel V-Bolt Saddle Clamps and U-Bolt Saddle Clamps. A total of four clamps are required, which are sold separately for flexibility. This versatile, rugged plate and the optional clamps combine to add a strong extension mast above and in line with the original larger mast. This plate makes it easy to add a mast top antenna, electronic device or a strut tube for a boom support truss above a directional antenna. The DXE-MTMP mounts a smaller, short piece of tubing with a 1.000 to 1.500 inch (25.4 to 38.1mm) OD (outside diameter) above a larger mast or mounting tubing or pipe of either 1.00 to 2.00 inch (25.4 to 50.8mm) OR 2.375 to 3.000 inch (60.3 to 76.2mm) OD. This is the mounting plate now supplied with the DX Engineering XB-5 Hex Beam HF Antenna, DXE-XB-5-MMK. The DXE-MTMP can be used to remount an existing Hex Beam, and it is sold here separately for alternative clamp choices. As shown in the images, the DXE-MTMP reinforced plate has two pairs of upper holes with 6 in. (152.4mm) vertical spacing to use either of these DX Engineering Saddle Clamps: Two DXE-SSVC-150P for an upper steel mast mounting a range of 1.00 to 1.50 in. (25.4 to 38.1mm) OD, OR Two DXE-SAD-150A for aluminum or steel tubing that is exactly 1.500 in. (38.1mm) OD. Two lower pairs of holes also have 6 in. (152.4mm) vertical spacing. Use either of these V-Bolt Saddle Clamps: Two DXE-SSVC-2P for a 1.00 to 2.00 in. (25.4 to 50.8mm) OD steel mast, OR Two DXE-CAVS-2P for 1.00 to 2.00 in. (25.4 to 50.8mm) OD aluminum mast, OR Two DXE-SSVC-3P for a 2.375 to 3.000 in. (60.3 to 76.2mm) OD steel mast. Each mast requires about 8 in. (~200mm) of clamping length. Internal reinforcement of aluminum tubing or double wall thickness is encouraged. NOTICE: A total of FOUR DX Engineering Saddle Clamps are required, two for each steel or aluminum mast tubing or pipe. Other brand general hardware u-bolts will not fit this plate. Holes are drilled for the specified DX Engineering Saddle Clamps only. The user is responsible for appropriate and safe mechanical installation. No data is available for loading strength or suitability of use.
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$50.99