Antenna Update & Lessons Learned

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After the previous post, I continued to work on the antenna configuration some more.  The easiest and quickest improvement that could be made was to add more radial elements to the ground plane.  After straightening, terminating, and heat shrinking four more 19.5″ 12 AWG wires, it was ready to go.  In the first photograph, you can see just the simple antenna assembly and tear down process requires only a screwdriver and a pair of needle nose pliers.

Homebrew Quarter Wave Ground Plane Antenna Teardown
Homebrew Quarter Wave Ground Plane Antenna Teardown
Homebrew 2m Quarter Wave Ground Plane Antenna With Eight Radial Elements
Homebrew 2m Quarter Wave Ground Plane Antenna With Eight Radial Elements

The antenna is great, but I think my radio is a dud.  I’ve got a camouflage Tonfa UV-985 handheld radio inbound from eBay, and it’s advertised 8W output is 3W more than the Baofeng.  I’ve heard a pretty convincing review from another amateur operator in the local area for the Tonfa, and his expertise is at a level that I’m sufficiently confident in his review being informed and impartial.

Not all of my efforts at making antennas have proved fruitful.  Here’s a 5/8 wave ground plane I made using similar construction techniques to the quarter wave models:

Failed 5/8 Wave Antenna
Failed 5/8 Wave Antenna

The signal quality from the antenna was great!  However, it wasn’t structurally sound and wouldn’t hold up its own weight.  I thought using a plastic wire conduit, some silicone caulk, epoxy, and heat shrink would be enough to secure it to the base, but it wasn’t.  This design also lacks a loading coil at the antenna base to match the impedance with the feed line largely because I didn’t understand how loading coils worked until post-mortem research.  I’m curious to try it again using copper piping, but that will have to wait for a while.

I’m going to change directions for the next antenna, and I’m considering stacking 3x quarter wave antennas together in a collinear array antenna with quarter wave matching stubs between the elements.  Theoretically, this should provide higher gain over a 5/8 wave antenna in roughly the same amount of space, and real world signal losses shouldn’t detract from this too much.  I probably won’t have the chance to start that project for a little while.  October is a busy month for our family schedule, and the weekends are fully booked for a few weeks.

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