Transcript
Dual Beam Pro Building Instructions
Manual REV E
DUAL BEAM PRO MULTI-BAND ROTARY HF ANTENNA
PRO ANTENNAS 3 Forsythia Close Hedge End Southampton SO30 4TP Tel: 01489 789960
[email protected] www.proantennas.co.uk
Copyright Pro Antennas 2010
The Dual Beam Pro Building instructions Congratulations on purchasing this unique antenna product. You can rest assured that it will provide you with many hours of operation pleasure for years to come. Please take a little time to carefully follow the instructions and study the pictures to help understand the correct positioning and alignment of various components. Tools required: Two 10mm spanners or single 10mm spanner plus 10mm socket and wrench. One 15mm spanner and a plain screw driver. Self amalgamating weather proofing tape and PVC insulating tape. Minimum coax feeder length: 20m (If this leaves you with excess cable then form a coil at the radio end to keep the installation tidy). Always use the highest specification 50 ohm coaxial cable that you can afford. The cable will need terminating with a PL259 plug on each end. The supplied parts check list: 4 x 35mm M6 stainless set screws 6 x M6 Nylon insert stainless nuts 6 x M6 stainless backing washers 1 x Galvanised mast head support bracket 1 x Pre-drilled GRP rod centre support insulator 2 x Matching transformer connection bars 1 x Pro Antenna matching transformer 1 x Jubilee clip to secure matching transformer 2 x End element securing brackets 2 x 3/8” Alloy elements with plastic end caps 2 x Pre-drilled 1” diameter main element sections Prepare the matching transformer by fitting the two connection bars. When tightening down the M6 nuts, use a spanner to hold the nut nearest the transformer body. Please carefully observe pictures for this method, see picture (1). When correctly fitted, the connection bars should look symmetrical as in picture (2).
(1)
(2) Copyright Pro Antennas 2010
Insert the GRP rod through the clamping section of the mast head support bracket, (3). The alloy centre should be centralised in the boom clamp, do not tighten just yet.
(3) (4) The two 1” diameter main dipole sections can now be joined at the centre to the GRP rod, only fit and tighten the two outer most 35mm M6 nuts and bolts. The previously prepared matching transformer can now be fitted, note the main support mast will be on the back side of the dipole element in relation to the matching transformer, picture (4) & (8). The end elements can now be fitted to the end of the 1” diameter horizontal sections. The end element brackets are fixed between the pencil marked rings approx 6mm from the ends of the 1” tubes. The square alloy tube on each 3/8” element is positioned as shown in picture (6). Position the clamp so that the element is horizontal when compared to the vertically fitted matching transformer. Tighten down the clamp until it is secure, now move to the opposite end and fit the second element. Position the clamp with the aid of looking down the length of the boom and use the far element to align the second element, note the end elements are on top of the 1” tube, see picture (5).
(5) (6) This is a good time to double check all nuts and bolts for tightness before moving on to elevating the DB Pro to the support mast. The antenna is best handled around its centre of gravity. Loosen the mast head support bracket ‘V’ bolts and lift antenna onto the support mast. If a rotator is being used, don’t fully tighten the 15mm nuts just yet, follow the rotator alignment instructions below. With the help of an observer on the ground, rotate the GRP rod through the clamp so that the end elements are perfectly horizontal. You can now fully tighten the two M6 nuts and bolts of the boom clamp. Copyright Pro Antennas 2010
Rotator alignment: The 3/8” end elements should point directly toward the desired countries direction, see picture (9). The DB Pro behaves like a selective rotary dipole, when beaming to the west, you’re also beaming to the east. Unlike a Yagi, you can cover 360 degrees with only 180 degrees of antenna rotation. When you are happy with your alignment, tighten the four 15mm mast securing nuts. Now you can secure the matching transformer with the large jubilee clip. Tighten this around the lowest part of the transformer body and not the mid narrow section, see picture 7 & 8.
(7) (8) You are now ready to connect your coax feeder terminated with a PL259, weather proof the cable connection with self amalgamating tape. The cable should not pull on your PL259 connection, therefore, tape the coax to the support mast with PVC insulating tape. (A small extra cable allowance is required to ensure the mast can rotate without restriction). In use, it is normal to see a standing wave ratio on your feeder and that is why this antenna is described as requiring the use of an ATU. The 40m and 30m operation will require an external ATU with a much wider matching range than the variety built into most modern HF transceivers. The Dual Beam Pro Specifications Turning radius required................................................................................ 2.5m Overall span of main rotatable element ....................................................... 5.0m Overall span of end elements........................................................................ 2.5m Total weight including support bracket and centre feed transformer .......... 4.0 kg The Dual Beam Pro is capable of handling an upper power limit of 400 watts PEP, however you must not exceed the maximum power specifications of your ATU. Aerospace alloys are used throughout, with excellent corrosion resistance and non-corrosive stainless steel fixings. Included is a heavy gauge steel galvanised mast head support bracket, suitable for mast sizes:1.5" to 2". The Dual Beam Pro is a non-resonant design requiring an internal/external ATU for 20m to 10m operation. Performance on 40m and 30m is acceptable for occasional use and operation on these bands requires a suitable external ATU. Copyright Pro Antennas 2010
How to optimise the beam heading of the Dual Beam Pro, the diagram below shows the positioning of the elements for peak performance in this case East & West (bi-directional). (This is not an azimuth plot of the Dual Beam Pro’s radiation pattern)
Picture No 9
Copyright Pro Antennas 2010
