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Build it: 2 meter Tape Measure Yagi Antenna

Discussion in 'Amateur Radio News' started by KB9VBR, Feb 7, 2017.

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  1. KB9VBR

    KB9VBR Ham Member QRZ Page

    On this episode of Ham Radio Q&A, I build a 2 meter tape measure yagi antenna. This lightweight antenna is perfect to use for fox hunts or as a portable directional antenna for public service events.

    There are plenty of plans online to build your own tape measure antenna, but no good step by step video that takes you through the process. So with that, watch the video and go ahead and build your own tape measure yagi.

    Michael, KB9VBR



    [​IMG]
     
    YO4FKO, K6BNE and AF7EC like this.
  2. W0RIO

    W0RIO Ham Member QRZ Page

    That's a nice and straightforward antenna project.
    If I built one, I'd use the tin snips to round the exposed ends of the metal tape
    then I'd sand it smooth. Those right angle corners can be pretty hazardous.
     
    KC3FPA/SK2023, K6BNE, AF7EC and 3 others like this.
  3. OK1AVG

    OK1AVG Ham Member QRZ Page

    When is windy...
     
  4. KA4AQM

    KA4AQM Ham Member QRZ Page

    This is a great project and a very functional 2m antenna. I have built several and gave most of them away. Buy cheap tape measures and hose clamps from Harbor Freight. Lowes or Home Depot has the pvc (did I mention cheap?) and use RG-8X for a 8 ft run. Terminate in a quality pl-259. I mounted mine on 6 foot pvc pipe, vertically polarized, bolted an older rotator to wooden floor in UFROG (unfinished room over garage), ran controller cable down to bottom floor and my older 25W "hi power" 2m rig has the teeth to run with the big rigs. Since it's inside, it's stealth, not exposed to corrosion, lightening, etc. You haven't lived till you've made one of these antennas. GL.

    Randy Melton
    KA4AQM
    Chesapeake Va
     
    K6BNE and KB9VBR like this.
  5. WQ4G

    WQ4G Ham Member QRZ Page

    Gee, I built one of those about five years ago. I guess I should have made a video.... I could have been on qrz.com.
     
    W0ZZG and K6BNE like this.
  6. WQ4G

    WQ4G Ham Member QRZ Page

    Randy: Lighting has no problem hitting that inside antenna. Been there and done that.
     
  7. KK5JY

    KK5JY Ham Member QRZ Page

    I had a friend who built on of those, but it didn't have any directivity. I didn't double-check his measurements, but when I compared it to an arrow antenna, it had no F/B or F/S. It might be a good idea post-construction to find a good source of in-band 2m signals, and test the F/S and F/B ratios to verify that the construction was successful. Maybe work someone on an HT on low power at a distance, to make sure that the directivity is good.
     
  8. KK5JY

    KK5JY Ham Member QRZ Page

    I had a friend who built on of those, but it didn't have any directivity. I didn't double-check his measurements, but when I compared it to an arrow antenna, it had no F/B or F/S. It might be a good idea post-construction to find a good source of in-band 2m signals, and test the F/S and F/B ratios to verify that the construction was successful. Maybe work someone on an HT on low power at a distance, to make sure that the directivity is good.
     
  9. KA4AQM

    KA4AQM Ham Member QRZ Page

    Danny-
    Just tongue in cheek, if lightening goes through my roof and hits the antenna, I've got a bigger problem to deal with. But seriously, with lightening in the area, I unplug everything anyway from antennas to AC outlets...but appreciate the comment!
    73
    Randy
     
  10. NU4R

    NU4R XML Subscriber QRZ Page

    BUILD an antenna? EWWWWW! Whatta' think we are?!? Ham Radio Operators or something for crying out loud?

    Seriously, good one Micheal! 73 & tnx! (And, what in THE WORLD is all that white stuff around you?!?)
     
    KB9VBR likes this.
  11. WQ4G

    WQ4G Ham Member QRZ Page

    Randy:

    Hopefully you are not just laying the disconnected coax line on the floor of the shack (with an open end). I used to do that - until a lightning strike took out my radio, amp, computer, refrigerator, telephone, stereo, and every other electronic device in the house. I even had one light bulb (in the lamp on my radio desk) that had a hole blasted in the base. When the lightning bolt hit the antenna and came down the coax it had no place to go. So it punched a hole in the braid and jacket of the coax about every 12 inches and came out all over the place and took the closest path to ground - through all my electronic stuff.

    Now days I have a ground bar in my shack with coax connectors welded to it and I screw all my coax lines to that. When lightning hits it goes straight to ground. In fact, I believe I have taken several direct hits to my antennas, over the past 20 years, with no ill effects. Now I am almost convinced my antennas, grounded in this fashion, keep the lighting away from the house and appliances.

    I would warn against just disconnecting your coax lines and letting them lay ungrounded on the floor of the shack... IMO you are asking for trouble. As I said at the beginning of the post - I hope you are not doing that.

    Dan KI4AX
     
    WA7PRC likes this.
  12. WA7PRC

    WA7PRC Ham Member QRZ Page

    Lightening the discussion with more lighting, I b'lieve the word missed (twice) is lightning. ;):p:rolleyes:
     
  13. KB9VBR

    KB9VBR Ham Member QRZ Page

    Glad you enjoyed the video. It's my experience that new hams are looking for easy tutorials like this. With a lack of mentors at the local level, they are turning to places like Youtube for inspiration and help.

    As for the snow; well, we Wisconsin hams aren't gonna let a little bit of the 'white stuff' keep us indoors. :)

    Michael
     
  14. KC8WIK

    KC8WIK Premium Subscriber QRZ Page

    Gees, he kinda looks like Adam Savage of the Mythbusters!o_O
     
  15. KQ7T

    KQ7T Ham Member QRZ Page

    Michael, great post. Thank you.

    I recall during my visit a few years ago to the air and space museum near Dulles, VA, seeing satellites sporting tape measure antennas. The reason was obvious. They are fully collapsible for launch, then require no assistance to fully deploy once in orbit. "Gosh, that's clever," said I to myself. I wondered if the idea came from a ham operator.

    In the case of your antenna, portability is just about optimum. Very nice.
     

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