[bars] Cobra Ultralite Balun

Sun Jul 3 16:54:20 EDT 2022

Is that balun something that came with the antenna from the manufacturer, or
something homebrewed by another ham?  If it is from the manufacturer it is
probably engineered to be OK as long as you are not running an amp, but it
does not look that heavy-duty.  Looking at your photo and counting distance
between studs (16") and doing the trigonometry, it looks like about 9 feet
or so of coax you would have to add to get the balun out of the house.  How
much coax do you already have in line in your room?

If the balun you have is not suitable, a W2AU brand 4:1 balun may be a
suitable alternative; that is what I have used, and it is an "industry
standard".  Though I am not suggesting you hack up your antenna if it came
together as a unit.  I do not know the specs of it; it may be fine.  See
what others have to say.

One thing you may run into is that  adding coax may put the match out of
range of your tuner at some frequencies.  But there is a trick you can play.
Have several assorted lengths of coax jumpers available (6 feet, 12 feet,
etc.) and enough barrel connectors to swap some or all  them in and out by
experiment.  You might be able to find a combination that works on all the
bands you operate.

Again, radio station NF1A welcomes the ""presentation of contrasting points
of view".

-Art

NF1A

From: bars <bars-bounces at w1hh.org> On Behalf Of Jason Sanroma
Sent: Sunday, July 3, 2022 4:00 PM
To: William Smith <w_smith at compusmiths.com>
Cc: bars at w1hh.org
Subject: Re: [bars] Cobra Ultralite Balun

Once it enters the house it goes into a crawl space (cubby hole) and then
through the wall into my shack. It goes through a balun but I am not sure
the specs of it and I believe it is not suited for this use, but I needed
one to use the LDG auto tuner. I will provide some pictures to show what I
am talking about.

The pictures show: The balun front and back, I am not sure the type of balun
it is. Then, the crawl space where it comes in and then the window line
going through the wall after that it shows it coming out of the wall. There
are a few other wires that are labeled such as the coax for the Super big
stick for 10m, my Diamond X-50A (2m/440) and ethernet. I am not sure if the
other lines can affect the VSWR.

73,

Jason

K1NAD

On Jul 3, 2022, at 9:19 AM, William Smith <w_smith at compusmiths.com
<mailto:w_smith at compusmiths.com> > wrote:

Where does it go after it enters the house?  

73, Willie N1JBJ

On Jul 3, 2022, at 1:03 AM, Jason M. Sanroma - K1NAD <K1NAD at sanroma.net
<mailto:K1NAD at sanroma.net> > wrote:

Hello,

I have a Cobra Ultralite Senior. It is approximately 105 feet up in my pine
trees. When the ladder line comes down, it goes through a porcelain
insulator and then through a slit of wood in the eave of the house. My
grandfather believes the VSWR is affected by its contact with the wood.

I was wondering if I should add a balun and run coax into the house instead
of the feedline? Does anyone have recommendations for the Cobralite antenna
balun?

I have attached a few pictures to explain what I am writing about.

Thanks.

73,
Jason
K1NAD

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