Showing posts with label dipole. Show all posts
Showing posts with label dipole. Show all posts

Tuesday, September 17, 2013

Behold the awesomeness that is to be my 160m dipole...

This is a paraphrase/enhancement of a cross-post that I made to Reddit.  I'm putting up a ladder-line fed 160m dipole in the near future.  I forgot the insulators when taking the picture...


I should be able to get it up to around 60' in the trees that I have available. It won't be perfectly straight so it will favor the southeast a bit (watch out Caribbean, I'm coming for you!), but it should be better than what I have right now. Here is the planned layout as of right now.



After working it out in EZNEC it doesn't look as if the slight jog will throw off the pattern that much. It's still basically an NVIS antenna at the design frequency. Or to say it another way, I don't have any 260' trees to make it act like it would at a half-wave up.


At 1.8MHz it is definitely an NVIS antenna:




At 3.8MHz it is starting to look a little better, but kinda looks like a tumor (this is the favoring of the SE that I mentioned above):


At 7.2MHz it is starting to look more like a traditional dipole over real ground:

Once you get up to 14.2MHz you start seeing some weirdness:


To be honest, the main goal is for this to be a multiband doublet that just happens to be cut for 160m. I'm okay with NVIS on 160 for now. If I really start getting into it I might try an inverted-L or a vertical at some point in the future.  Several Redditors made that suggestion.

Total cost of the antenna is:

$47 for the wire at Home Depot
$50 for the spreaders and center support
$24 for the dacron rope at tractor supply
$06 for the insulators
$127 total

And I have enough wire left for a 40m end fed half wave for my Rockmite-40 with enough rope for hanging that as well. So I guess it was basically $127 for two antennas (plus the xformer parts for the efhw).  Not too shabby as one comment that I got so eloquently put it!  ;-)

73,

Richard, KK4JDO

Monday, June 11, 2012

First Antenna, 1/2 wavelength 10m dipole

Hi All,

So, since this is about Ham Radio, you had to have guessed that there would be talk about various types of antenna.  I have a terrible dislike of spending money, so instead of buying my first antenna, I decided to build one instead.

As a newly minted Technician class Ham Radio Operator, the only HF bands that you have voice privileges on is the 10-meter band (28.3MHz - 28.5MHz).  You can operate CW on a few lower bands, but since I am still in the process of learning Morse Code  (CW), I decided to build an antenna for use where I can talk on voice (using what is called SSB or Single Side Band).

A dipole is a very basic antenna, and very easy to build.  Basically, you need some wire, and something to use as a feedline, such as coax or twinlead.

My Parts List:


  • 20' of stranded copper wire
  • 1 x 3/4" PVC "T" fitting
  • 2 x 2" pieces of 3/4" PVC pic as insulators
  • 20' of nylon rope
  • 100' of 300-Ohm twinlead from Radio Shack


Time to Completion:


  • One hour to measure, cut, solder, mess-up, re-do, and finish.
  • One additional hour to hang between two trees.


Here is a quick pic:


Once it was up in the air, I connected it to my radio via my tuner, and was talking to California, Idaho, Montana using SSB on 28.4MHz!

That it for this post, hope you enjoyed it!

73,

Richard, KK4JDO