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Re: [TenTec] [SMC] OT: Half inch Andrews Heliax LDF4-50A vs LMR-400

To: <mjwetzel@comcast.net>, "Discussion of Ten-Tec Equipment" <tentec@contesting.com>
Subject: Re: [TenTec] [SMC] OT: Half inch Andrews Heliax LDF4-50A vs LMR-400
From: "Bob McGraw - K4TAX" <RMcGraw@Blomand.net>
Reply-to: Discussion of Ten-Tec Equipment <tentec@contesting.com>
Date: Thu, 25 Apr 2013 16:57:03 -0500
List-post: <tentec@contesting.com">mailto:tentec@contesting.com>
That's why I use N type connectors. Much more likely to be water proof when installed correctly. UHF connectors are inexpensive and not considered water proof. Most commercial installations will use N type connectors for waterproof reasons and constant impedance reasons. Of course they are more expensive.

I see a N connector on the line at the house, N connector on the line at the top of the tower. Then N connector with a piece of RG-213 on one end and a UHF on the other because that's what the balun uses. That the maximum number of connectors exposed. No adaptors required.

I have 6 runs of LDF4-50 configured this way and up the tower at the house. The 100 ft repeater tower as 12 runs of LDF4-50 with an antenna on each one.

73
Bob, K4TAX







----- Original Message ----- From: "Mike Wetzel" <mjwetzel@comcast.net> To: "'Craig Thompson'" <craig@thompsonet.com>; "'GARY HUBER'" <glhuber@msn.com> Cc: "'SMC'" <smc@w9smc.com>; "'TenTec Reflector'" <tentec@contesting.com>; "'W9AML group-email'" <w9aml@midlandsnetworking.com>; <DX-IS@yahoogroups.com>
Sent: Wednesday, April 24, 2013 12:07 PM
Subject: Re: [TenTec] [SMC] OT: Half inch Andrews Heliax LDF4-50A vs LMR-400


I would also agree with Craig.

There are more possible failure points with the connections but really not
loss.  If there was loss the connectors would heat up which they really
don't.  Imagine how hot it would be if you were running RTTY at full power
and you had just .1 db loss at a connector in a sealed connection.

Mike W9RE

-----Original Message-----
From: SMC [mailto:smc-bounces@w9smc.com] On Behalf Of Craig Thompson
Sent: April 24, 2013 12:53 PM
To: GARY HUBER
Cc: SMC; TenTec Reflector; W9AML group-email; DX-IS@yahoogroups.com
Subject: Re: [SMC] OT: Half inch Andrews Heliax LDF4-50A vs LMR-400

Hi Gary

I would use the 1/2" Heliax. I use both and the outer jacket of the Heliax
is superior to the LMR for both water and sun. It also has lower loss. I
would use LMR400 UF or similar for the rotator loop. Use all UHF connectors
for connections.

73, Craig K9CT


On Wed, Apr 24, 2013 at 11:37 AM, GARY HUBER <glhuber@msn.com> wrote:

  As I consider the materials required to replace my 30 year old tower,
rotor, antenna and cables, I have several like new runs on LDF4-50A
terminated with N-male which could run from my ground window (UHF female)
to the top of my 53 foot tower (60 feet max LDF4-50A cable run)  where a
flexible low-loss 10 foot jumper would terminate on a new BN-4000 and new
TH-7 tribander. This configuration would require the 60 feet max LDF4-50A
cable run,  two half inch N female to UHF male adapters, one UHF double
female and 10 feet of high quality RG8 cable as the jumper to the BN-4000.

The alternative which I'm leaning towards as it seems less likely to have
connector/adapter loss and other potential problems is a single run of 75
feet of LMR-400 with factory terminated PL-259s between the BN-4000 and
ground window UHF female termination. My current installation is 60 feet
of
RG-9913, a UHF double female adapter and a ten foot RG-8214 jumper.

I know the half inch Andrews Heliax has a much lower loss figure (0.357 db
per 100 feet at 30MHz) for a given length versus the same length of LMR
400
(0.7 db per 100 feet at 30MHz) , but I'm thinking those three adapters
(six
connection points for loss) and their potential problems make it a wash or
maybe the advantage goes to the 75 foot run of LMR-400.

I'd be interested in any comments or experiences you might have on the
subject.

73 ES DX,
Gary -- AB9M





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