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

[Mike Wetzel]

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 at 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 at 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 at 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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