[SFDXA] KB6NU's February 2015 Column

[Bill]

Hi, all:

This column is a little early and a little longer than usual. I guess I just felt prolific this month.

If you want a photo of yours truly to go along with the column, you can find one of me at http://www.kb6nu.com/wp-content/uploads/2015/01/kb6nu-key-600x400.jpg. Feel free to crop as necessary.

73!

Dan KB6NU


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Make your own dipoles with these center insulators

By Dan Romanchik, KB6NU

One of the things that always gets my goat is the price some companies charge for dipole antennas. It's not that they're charging an outrageously large sum of money, and I certainly don't begrudge them making a profit for their efforts. It's just that if hams would just buy their own wire and parts, they would not only save money over the long run, but be encouraged to experiment with antennas. That's what I started doing about ten years ago, and I've been very happy with the results.

One of the first things that I did was to purchase ten Budwig HQ-1 center insulators and ten HQ-2 end insulators (http://www.budwig.com/antenna-connector-insulators.html). I've made a bunch of antennas with these insulators, including several 40m/20m inverted vees for portable use (such as Field Day and special events), a 17m dipole, and a 10m loop antenna. These insulators are very well-made, and can easily be reused, too.

Universal Radio sells the set (http://universal-radio.com/catalog/antsup/1782.html) for $18.50. I just placed another order for ten HQ-1s and 20 HQ-2s (the minimum number that you can purchase to get a quantity discount). The price, including shipping, is $143.

There are a bunch of other center insulators on the market, including:

   * The Alpha Delta Delta-C antenna hardware kit (http://universal-radio.com/catalog/antsup/0297.html) consists of a Delta-C Center Insulator, antenna connecting hardware, 1 SEP Arc-Plug™ static protector (installed in Delta-C) and 2 Delta-CIN end insulators. This is a little heavier-duty than the Budwig insulators, but it costs more, too ($30 at Universal Radio). Unless you're going to be running a kW, I don't see the need to spend nearly twice as much money on these insulators.</li>
   * The TEN-TEC ACRO-BAT Antenna Connector & Hanger (http://www.tentec.com/products/ACRO%252dBAT-Antenna-Connector-%26-Hanger.html) is an interesting product. Unlike the Budwig and Alpha-Delta insulators, this product does not have an SO-239. Instead, this insulator clamps over the coax and antenna wire, and in doing so, provides strain relief. I haven't tried this one, but it seems like a nice design. The cost is $10, directly from TEN-TEC or from Universal Radio.
   * The Unadilla W2AU ANsulator (http://universal-radio.com/catalog/antsup/0913.html) is made from PCV tubing and include eyelets for terminating the antenna wire and for supporting the insulator in the middle. For $15, I think I'd rather have the Budwig insulator. Also, you should be able to make one of these insulators for less than 15 bucks.
   * The Hy-Gain C-1C Center Insulator (http://www.hy-gain.com/Product.php?productid=C-1C) has a screw for tightening down the antenna wire, so you don't have to do any soldering, but overall, I don't think I like the looks of this model. And, at 30 bucks, it seems kind of pricey.
   * The W8AMZ Dipole Antenna Starter Kit (http://www.w8amz.com/W8AMZ_ACC_Page.html) comes a center insulator made from PVC pipe, similar to the Unadilla W2AU ANsulator and two end insulators. It costs $18.
	
If none of these strikes your fancy, you can always make your own. WP4AOH has some very good instructions on how to do this using PVC pipe and fasteners that you can find at your local hardware store (http://wp4aoh.blogspot.com/2012/07/dipole-antenna-center-insulator.html).

Whatever route you take, I encourage you to keep several on hand and enough antenna wire and coax to complete the antenna. You never know when the urge will strike you to build an antenna, and if you don't have the parts you've missed an opportunity to do some experimenting.

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When not checking his stock of antenna parts, you'll find KB6NU working on updates to his "No Nonsense" study guides, blogging about amateur radio at www.kb6nu.com, or working 30m CW.

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