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

[Craig Thompson]

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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