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  • Author Author: kmikemoo
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2 Year Antenna Project

kmikemoo

In the midst of this "work of art", is an antenna.  It's been there since March of 2023.
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In January of 2023, I read an article in QEX (a magazine published by the ARRL) by Richard Quick, W4RQ, on a 2 meter loop antenna made with an aluminum yardstick.  I was intrigued.  I'm also forgetful sometimes - so I didn't get around to buying a yardstick until the weekend before I wanted to use the antenna (late March).  Being me, I also way over thought the project.  36 inches will surely be too short - so I bought a meter stick from Ace Hardware.  But the build instructions said use a yardstick - so I went back out and bought a yardstick from Harbor Freight.  At least that way I wouldn't be out a lot of money when the antenna ended up being too short.

Over the remainder of the weekend, I build both antennas.  Bend them in thirds.  The Harbor Freight one has a hole for hanging so that means the top bends are going to be extra short.  No problem.  I have infinite faith that the meter stick antenna will work flawlessly.  I have so much faith that I paint it right away.  The antenna is for a hidden transmitter so dulling that bright aluminum seems like the right thing to do.  One coat.  Let it dry.  Two coats.  Let it dry.  Now it's Thursday night.  I need this thing for Saturday morning at 0730.  I put it on the antenna analyzer and... its resonant frequency is 136MHz.  Fantastic for US NOAA Weather Satellites but a far cry from the 147.555MHz that my transmitter is going to use.  Try this.  Try that.  If I re-bend it, I'll mar the paint.  Admit defeat and go to bed.  Throw the antenna on the garage work bench.

After work the next day, it's 4th down and long yardage.  It's time for a Hail Mary play.  I get out the Harbor Freight yardstick version and put it on the antenna analyzer.  Tweak this.  Tweak that.  It's got its lowest Standing Wave Ratio (SWR) of 1.2 at 147.56MHz.  "Are you freakin' kidding me?!" and other rants ensue.  It's bright silver.  There's no time to paint.  Besides, it's cold in the garage and I'm not going to stink the house up with spray paint.  It will have to do.  "Seriously!!"

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The bright silver Harbor Freight yardstick antenna worked great.  I had to enlist the wife's help to locate it after the event - even though I was standing right in front of the tree I hid it in.  All is well.

Except for that non-resonant antenna sitting on the workbench.

WELL... I finally made the time this week to tune it.  Two years later.  Cut.  Flatten.  Bend.  Drill.  Still too long.  Repeat.  I ended up taking off about... three inches total.  Imagine that.
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Not bad.  When you are only transmitting 50mW, every little bit helps.

Now to work on all the other stuff on the bench. Frowning2

  • in reply to shabaz

     VERY nice!  I look forward to your blog. Relaxed  I do also own the MFJ-259D, a NanoVNA and a TinySA.  BUT...not that I need another analyzer, but I'd love to build one - just because.

    I recently revisited your PicoSynthRF project.  Thank you for doing/sharing that. RelaxedThumbsup

  • Nice work! Interesting shape for a loop antenna. I notice you're using a decent analyzer..

    I've been trying to build a cheap analyzer, front panel below. (Not my design, it's some old magazine article). I'll write a blog post on it once I've worked on it a bit more.

    It won't be anywhere near as sophisticated as the one you're using, but hopefully usable at a pinch.

    image

  • in reply to kmikemoo

    Build plan?  That's funny.  I just looked online at a few designs and started experimenting.  I just used a 1m loop of copper tubing and tuned it up using the same antenna analyzer you've got.  Some designs have a tuning cap on the large loop, mine doesn't.

  • in reply to beacon_dave

      Laughing  Working with that stuff is a bit like trying to train a cat.  You know what you would like it to do.  It does what it wants to do.

    I have built two tape measure Yagi-Uda antennas.  Two because I had to add reinforcing PVC to one of them so I could use it when there is even the slightest wind.  Anyone that has one knows exactly what I'm talking about.  I also tried using tape measure antennas for a TDOA direction finding antenna.  Oye!  If you thought the Yagi flopped around...

    AND... because I'm an exceptionally slow learner... Slinkys are on the build plan - just not for 2 meters.

  • Better late than never.

    Not bad for a simple antenna.