Towertalk
[Top] [All Lists]

Re: [TowerTalk] Crappy LMR600

To: towertalk@contesting.com
Subject: Re: [TowerTalk] Crappy LMR600
From: Jim Brown <jim@audiosystemsgroup.com>
Reply-to: jim@audiosystemsgroup.com
Date: Thu, 24 Aug 2017 11:05:52 -0700
List-post: <mailto:towertalk@contesting.com>
I agree with all of this.

AND -- a point that is often missed is that below about 500 MHz, transmission line loss is entirely due to I squared R. The only benefit of a foam dielectric is to allow the center to be larger for a given shield size. THAT'S why foam coax has lower loss below 500 MHz. Those who understand this use hard line for long runs from the shack to the top of a tower (or to the bottom of a crank-up) and a RG8-size coax for stuff that has to move.

As to high dipoles -- I use them for 80 and 40, and feed them with a good RG11. Tension is about 100#, supplied by water jugs filled with dry sand on one of the two support ropes that go through pulleys in the trees that hold them.

73, Jim K9YC

On 8/24/2017 9:28 AM, Clay Autery wrote:
Overkill?  Depends on your goal...  Mine is to NOT have to do
unnecessarily frequent maintenance/replacement.  And a wet cable is
unnecessary.
Wasted Money?  I bout the "-DB" stock I used last for less than a dime's
difference.  As it will likely last TWICE as long, it was a bargain.
Heavier?  Insignificant except for MAYBE wire dipoles with no middle
support...  Use better engineering or bigger dipole wire and pull more
tension.  Or don't worry about getting it perfectly flat.
Unsuitable? Matter of opinion even in your subset of wire antennas.

I will reiterate what my Dad taught me:

"If you cannot afford to do <insert task> once, you certainly cannot
afford to do it twice."

_______________________________________________



_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk

<Prev in Thread] Current Thread [Next in Thread>