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Flexible compact dipole antennas


Tom Visser

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Just an informal run - took a little walk around the neighborhood.  TRX-900LA @ 25mW, placed in a corner of my house with lots of appliances, chargers, wires, i.e. a bad RF spot.  2 separate QRX-100 were running, one with 1/4 wave whips and other with dipoles.  Walking down the alley across the street from my house, it seemed that the 1/4 wave whips started to show RF blips / red LEDs first, but with diversity tuning, still kept "online" while the dipoles were more consistently showing 2 green markers.  I started getting hits on the 1/4 wave whips and then maybe 10% to 20% the distance later, started getting hits on the dipoles.  It's certainly not night and day difference in performance, but shows some improvement when mounted directly to the QRX.  I suspect, that if placed on a micplexer or other device with amplification, that the dipoles would show even better performance over whips as the signal to noise ratio of the dipoles should be better than the 1/4 wave whips.  Will try to do something soon with quantitative measurements.

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I found a guy who was making similar antennas for other radio gear, contacted him, and had him make me some with my desired center frequency tuning.  I don't know the exact construction method, but the part where the ground plane shield element would go has a nice semi-rigid tube, so the antenna keeps its shape and gives enough heft and strength without becoming overly bulky.  The part between the tube and SMA, a very short section, is flexible and of course the positive antenna element is flexible too.  I had 6 antennas done for $65 shipped from the Ukraine, which is where my man "Oleksandr" is from.  I don't want to publicly list his email, but message me and I'll PM you it.  He was quick and when I told him I wanted special color heat shrink he was agreeable to doing custom work.  They didn't have brown shrink for my B21 antennas at his market, but used "stone red" instead.  I will definitely use him again for future antenna needs, the quality so far meets my expectations.

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  • 9 months later...

Just wanted to update this thread as Alexandr's email changed slightly...

baliv@email.ua

Just email him what you need and he accepts paypal.

shown below are 4 more antennas in B25 (this time all black shrink with little green caps) and also a pair of Zaxnet antennas with a specified center frequency of 2.439 GHz.  All this for $66 shipped from Belarus to Hawaii (don't hold me to this as I may have received a courtesy price break).

 

IMG_20160514_203245_609.jpg

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