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Tape measure beam

MNwr786

Member
5 elements on 2 meter and 10 elements on FRM/GMRS for direction finding. This was definitely not a $20 half-hour project like other tape measure beams on youtube. I'm $105 and 2 days into this and still need to do the feed points/matching, balun, diplexer and switchable attenuator. My first problem came when the 4-way PVC adapters had an internal shoulder and a few elements would be too close for the entire adapter. You think i could find a 1 1/16 drill bit in town? Nope. Had to find an old socket that fit snug and cut teeth into it to ream them out. Then, getting the 2m/FRS spaced so none overlapped led me to chop off the 4-way ends that fit over the pipe. Next came the custom grinding to make the 2m tapes lay flat across the 4-ways. The need for precision spacing led to the expensive purchase of lotsa hose clamps to use as guides when gluing. I ended up using super33 electrical tape to attach the elements and making that permanent with PVC cement made a nice mess on the deck. Anyhow, the hard part is over and now I get to pull out the VNA and tune this bad boy up. One more day and I should have an indestructable portable direction finding beam. Been quite the project!
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road squawker

Active member
GOLD Site Supporter
Wow!!!!
turned into quite the project.

Looks good construction wise
let us know hoe it tunes up on the band(s).
 

MNwr786

Member
I have not got back to the beam yet, although I did look into the diplexer a bit regarding component values. I need to find a metal project box for it. Hoping to get back to it tomorrow. Ill post a shot of the results on the NanoVNA when I get it done.
 
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