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

[Bob McGraw - K4TAX]

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 at comcast.net>
To: "'Craig Thompson'" <craig at thompsonet.com>; "'GARY HUBER'" 
<glhuber at msn.com>
Cc: "'SMC'" <smc at w9smc.com>; "'TenTec Reflector'" <tentec at contesting.com>; 
"'W9AML group-email'" <w9aml at midlandsnetworking.com>; 
<DX-IS at 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 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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