Author Topic: Impressive DIY HAM radio antenna for 2m/70cm. Will roll up in to your pocket!  (Read 4911 times)

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Offline inh

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I just built the antenna in figure 4, taped it to my sliding glass door, and did some quick tests. I can hear the next county's police department clear as day, much better than with the antenna that came with my hand held radio. The signal comes in stronger and with less static. I can also turn down the power to low (0.5 watts) and I can hit a repeater 20 miles away, with a Kansas mountain (hill) in between us.  :thu:

Check it out: http://www.arrl.org/qst/2007/03/fong.pdf

The best part is, this antenna can be made for cheap, and will roll up and fit in your pocket. There's no reason not to bring this with you whenever you head out with your radio. String this up in a tree with some fishing line and you can vastly improve your reception. There is also a version in the PDF designed for mounting in to a PVC pipe that you can paint and mount on the outside of your home.

I ordered 25 feet of the 300 ohm twinlead from here for $8.99 and a 12 foot jumper cable made of RG-174 designed for flexibility, terminated in BNC conenctors on each end, from here for $20.10.

Cut the RG-174 in to 2 5 foot lengths, and use the extra foot or so in the middle for the 4.25 inch piece you need for the antenna. For $30 you now have enough cabling to make two antennas, cheaper than you could buy just one for. The 25 feet of 300 ohm twin lead came in handy as well, because I messed up the first two antennas I made  :pod:
It is always better to have and not need than to need and not have.

Offline inh

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Here's some pics:





It is always better to have and not need than to need and not have.

Offline Syphonius

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Very cool!  I'll be going through that article.

Do you have an HT with wide receive?  I'm curious how all that length would boost my AM/shortwave reception on my 2R and 5R.
... iam pridem, ex quo suffragia nulli  uendimus, effudit curas;
nam qui dabat olim imperium, fasces, legiones, omnia,
nunc se continet atque duas tantum res anxius optat,
panem et circenses. ...

Offline inh

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It only receives 108-520 and 700-999, the antenna would definitely help out on 150 and 450 MHz receive, not sure about other bands. Make one and let us know ;)
It is always better to have and not need than to need and not have.