Great antenna: K1JEK's Cobra Ultra-Lite Senior

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K8CPA

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Feb 11, 2010
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Lincoln Park, Michigan
I did a review on it on eham. But, I wanted to post about it here too.

I've had it up a few weeks and it performs excellent. :D

Now, to be honest. It won't work on 160. At least not really well. It's too short. 70 ft a side is 70 ft a side. and that's just too darned short for 160; at least with any kind of signal.

However, I have gotten reports of 20 over S-9 on 75 meters... and that's at 150 watts on this Kenwood TS-950SDX. I use mine with a MFJ 989C roller inductor and it tunes it right up. In fact, 90% of the time; when I am on 40, I have the roller inductor tuner in bypass and use the tuner on the radio. The only bands that I HAVE to use the tuner on, is the 30 and 75 meter bands. The radio just won't tune those bands with this antenna.

Now, I use mine with an ugly balun, which you can read about here: BUILD AN AIR WOUND 1:1 CHOKE BALUN FOR HF - THE UGLY BALUN!. Scroll down, you'll see mine. I just removed old antenna, cut the twin-lead a few out from the ugly balun and and soldered the new stuff to the old twin-lead, shrink wrapped it, and put some caulking on it to keep the water out.

Now, keep in mind. I did not use the whole 100 feet to twin-lead that it came with; as I didn't have anywhere to put it in my backyard. But, I did use enough of it for it to work. At least for what I use it for.


Here is a video of yours truly doing a walk-around of my antenna set up. If you can tolerate my huffing and a puffin' and little bit of absent-minded swearing. (not too much though...) you can click here and watch the video: https://www.youtube.com/watch?v=f-k1eoY17tI

Anyhow, enjoy the video and if you've got a small lot and can spare 140ft... this might be what you are looking for.

73 de Chuck K8CPA
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K8CPA

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Joined
Feb 11, 2010
Messages
264
Location
Lincoln Park, Michigan
Just to add to this here....:

It does work on 160... I didn't think it would. But, locally in Michigan, it works fine. In the summer is a bit rough, with all the static. But, in the winter time, you can't beat it.
 

nanZor

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May 28, 2009
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Hi Chuck - looks like fun.

You may want to consider replacing the ugly-balun with one made of ferrite instead. Reason being is that ugly baluns are somewhat narrow and can be ineffective depending on what band you are on - especially take note of the air-core versions (ugly balun)

Common-mode chokes

Looks like your choke may actually be doing much of nothing on 75m, and 10 meters. 30m actually looks ok, but still ugly baluns present an inductive reactance to the system common mode, which ferrites don't and may allow you to tune up on 30m. Strive to achieve at LEAST 1K of choking impedance.

An inexpensive one that comes to mind is an MFJ-915, although at 80m and certainly 160m, perhaps TWO of those would be wise or some other heavy duty equivalent.
 

AC2OY

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Mar 29, 2011
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Belleville,New Jersey
I enjoyed that Chuck...LOL you have a good sense of humor. I hope to work you someday!! Where or what bands,frequencies do you frequent?
 
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