2M Portable Beam

2M beam for JOTA Fox hunting.

Has to be robust and cheap. Also due to the ability to pack down could use for SOTA.

This is a  ‘tape measure’ beam made  popular by RDF – WB2HOL Tape Measure Beam.

Using a Byonics 2m Fox programmed to 145.3Mhz  and want to support 145.600 for SOTA. 

Tape fig1

I based this on the BUILDING THE WB2HOL FOXHUNTING BEAM page as it has metric measurements and designed for 145.450 Mhz.

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PVC components. The hardest parts were the X pieces. Not available from plumbing suppliers or hardware shops. Obtained from irrigation shop.

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Elements cut from single 8m tape measure. Making two here.

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Director and reflector are to be attached by a single screw each. Finding the middle is easy. Drill a hole in the middle and done. 

Tape fig2

Hairpin detail. Not using tape as will secure with hose clamps. Cut from discarded electrical wiring so solid core.

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The boom and hair pin ready to be attached. Had to clean and finn the tape measure for a good joint.  The driven element will be scoured by hose clamps as looking for a solid connection that scouts can’t break.

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Assembled ready to test. Borrowed the MFJ-269 from BARG club so will be able to tune.

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Trimming was easy as cut by mm. Tuned to 146.500 to support voice tx from a SOTA peak.

Ready to test. <Insert results>

Cost $40 for two. Purchased component from the two major hardware suppliers. Supplier M is new to market and considerable cheaper. The components (15mm pipe, ‘T’ ‘L’ and end cap and hose clamps) cost $16 from supplier B whilst same components cost $6 from supplier M. The PVC was twice the price whilst hose clamps 2.5 times more expensive. Sourced the X pieces at $2 each from local irrigation supplier after both hardware suppliers and two major plumbing suppliers could not help.

Took a afternoon to make two. Only had one BNC connector so only finished one. Also picked up 7 SOTA and 3 NP activations. Finally  to prove humans see what we want to,a blob of solder in the shape of Australia, whilst tassie is included unfortunately all the best peaks are missing as the dividing range is gone.

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Also 2M ‘Slim Jim’ from ladder line,

 

 

 

Allen

VK3HRA

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