[UK-CONTEST] Hardline query (M0XDF)

[Darrell G0HVQ]

Cris makes some very valid points.

I did done calcs on my setup and was surprised that the cable attenuation 
figures were so high, as I was getting plenty of QSOs. So I went out into 
the field and did some measurements. I'm using LDF5-50 to the VHF mast and 
some smaller hardline out to the HF vertical, both approx 150ft runs.

On 2m, I'm losing 50% power, not that surprising

But down on HF there is still significant attenuation e.g. for 100W in, 
approx 65W on 10m, 80W on 20m, and even only 90W on 40m.

I reckon a lot of us hams choose to ignore cable/connector attentuation, I 
certainly did for my first 20 years in the hobby.

If you ask around, you can normally get secondhand Heliax cheap (I did) as 
it's a pain to work with, hard to get rid of and connectors cost a fortune.

73
Darrell G0HVQ


----- Original Message ----- 
From: <gm4fam at tiscali.co.uk>
To: <uk-contest at contesting.com>
Sent: Thursday, January 08, 2009 3:11 PM
Subject: [UK-CONTEST] Hardline query (M0XDF)


> David
>
> Just to follow up G4ASR's helpful reply the cable he quotes is top of
> the range for performance and quality.
>
> Its not cheap (but nor is reasonable quality co-ax these days); and
> the connectors come at a price too - but its surprising how many will
> spend a 4-figure sum on an HF beam and use inferior feeder.
>
> For HF many amateurs use LDF4-50, and the much larger diameter LDF6-50
> for VHF; there are exceptions - a fellow DXer chaser 11km from me uses
> 6-50 on all bands, incl 160!
>
> It is obviously especially useful for long runs to any antenna because
> of its very low losses but I would recommend its use for any antenna -
> I use 4-50 for all antennas from 160m upwards (they are 300 + feet away
> from the shack) and have enjoyed significantly better performance since
> changing from RG-213 (to a small lottery win will ensure an upgrade to
> 6-50).
>
> If you get some there are 2 caveats:-
> 1) Don't bend it too much, and
> 2) Don't drive over it!
>
> The link below will take you to the Andrew's product range:-
>
> http://awapps.commscope.com/catalog/product.aspx?id=269&page=1
>
> 73 Cris
> GM4FAM
> PS: I don't work for the Company!
>
>>Could someone explain what hardline is please - I've come across
> this
>>in US mails, but no idea what it is.
>>73 de M0XDF
>>Hardline is a 'merrycan' expression for solid-shielded coaxial cable
> such as
>>the 3/4" Andrew LDF5-50 etc.
>>Similar cable is made by Belden.  It my 160M case the  feeder
> (hardline) is
>>Andrew LDF4-50 as I have tons of it. Almost literally.
>>
>>73 David G4ASR
>
>
>
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