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Re: [TowerTalk] More on CATV hardline connectors

To: <towertalk@contesting.com>
Subject: Re: [TowerTalk] More on CATV hardline connectors
From: "Tower (K8RI)" <tower@rogerhalstead.com>
Date: Fri, 27 Feb 2004 18:07:33 -0500
List-post: <mailto:towertalk@contesting.com>
These are what I used.

http://www.rogerhalstead.com/ham_files/conn.htm

Roger


>
> I have continued my search for good connectors for my CATV coax.  As I
> mentioned in my previous post, the first step is to figure out exactly
> what kind of coax you have.  I found most of mine on the Commscope website
> (www.commscope.com) and I have the QR type coax in various sizes.
>
> When I got the coax, I did also score a few pin type connectors for the
> coax.  At first, I had no idea that these were actually useful.  Normally,
> the pin goes inside some kind of equipment like an amplifier.  However,
> you can screw the outer housing of a N connector onto the threads and by
> cutting the pin at the right length (and deburring it), you end up with
> a male N connector (thanks K2UA for this hint).  You can use whatever
> adapters you need at that point.
>
> These pin connectors can be found pretty cheap.
>
> At www.tmbrokersmontana.com I found the ones I needed listed and the
prices
> very reasonable (depending on the size, from $3.50 to $6 each).
>
> They also had some splices for my larger hardline for just under $10 that
> will allow me to put together some shorter pieces to make a nice long
> one.  You can find instructions on how to prepare the cable on the
> manufacturer's web site in most cases.
>
> Even if you can't find these surplus, I found other places that had them
> new for not too much more money.
>
> Also - remember that e-bay is a great place to find your coring tools to
> prepare the coax.  Expect to pay $20 to $35 for them.
>
> Not happy about using 75 Ohm coax in your feedline?  You can construct a
> simple transformer to change 75 Ohms to 50 Ohms.
>
> The JULY-AUGUST 1981 issue of the NCJ shows how to make one.
>
> Cut 0.08165 wavelength lengths of 50 Ohm coax and 75 Ohm coax (mind your
> velocity factors!!).  Splice them together and connect the 75 Ohm end to
> your 50 Ohm load/tranmitter and connect the 50 Ohm end to your hardline.
>
> The NCJ shows the following lengths for Regular RG8/11 or foam RG8/11:
>
>          regular (.66VF)        foam (.79VF)
>     80M    14' 8"                 17' 7"
>     40M     7' 5"                 8' 10"
>     20M     3' 9"                 4'  6"
>     15M     30"                   36"
>     10M     22"                   27"
>
> They are pretty broadband.   I recently made one for 24 MHz that works FB
on
> 15 and 10 meters.  I have also used them on six meters on both ends of my
> hardline with 1500 watts without any problem.
>
> For 2 meters and above, I try to cut the hardline to be some number of
half
> wavelengths long - so that the impedance will be the same at each end.
You
> can test this with an SWR meter with the far end open.  Trim the length so
> that you have high impedance (>= 1000 Ohms).  If you do this, you don't
need
> to use any kind of impedance transformer.  Put 50 Ohms on one end and you
> will get 50 Ohms on the other.
>
> 73 Tree N6TR
> tree@kkn.net
> _______________________________________________
>
> See: http://www.mscomputer.com  for "Self Supporting Towers", "Wireless
Weather Stations", and lot's more.  Call Toll Free, 1-800-333-9041 with any
questions and ask for Sherman, W2FLA.
>
> _______________________________________________
> TowerTalk mailing list
> TowerTalk@contesting.com
> http://lists.contesting.com/mailman/listinfo/towertalk
>


_______________________________________________

See: http://www.mscomputer.com  for "Self Supporting Towers", "Wireless Weather 
Stations", and lot's more.  Call Toll Free, 1-800-333-9041 with any questions 
and ask for Sherman, W2FLA.

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