The direct burial coax I have used is quite stiff (I don't recall the brand
off hand). There is some
that is supposedly more flexible. The stiff stuff I have works in a rotator
loop at the top of the tower
but it is a relatively large loop (it's been up about 10 years).
73, Larry W6NWS
----- Original Message -----
From: "Perry - K4PWO" <k4pwo@comcast.net>
To: "Tower and HF antenna construction topics." <towertalk@contesting.com>
Sent: Friday, February 26, 2010 7:38 PM
Subject: Re: [TowerTalk] Frequent crankup coax recommendation
> For repeatable bends, I believe it is more like a 6" minimum radius. Most
> LMR type cables use a copper flashed aluminum inner conductor. Aluminum
> will work harden and stress crack from repeat bending so you want the
> radius
> as large as you can get it. Past posters have mentioned using 30+ gal.
> trash cans as the "receiver" for the coax coils when the tower is lowered.
> I would think that would be a large enough radius... YMMV. I've never
> used
> the direct burial stuff but if it's a flooded cable, it may be stiffer
> than
> normal LMR400 - which is already fairly stiff. If you are familiar with
> RG-213, I would estimate that you have twice the "stand out" distance (how
> far a section of cable can be held horizontal with only one end supported)
> with LMR400.
>
> 73 de Perry - K4PWO
>
> --------------------------------------------------
> From: "Jim Miller" <jim@jtmiller.com>
> Sent: Friday, February 26, 2010 18:10 PM
> To: <TowerTalk@contesting.com>
> Subject: [TowerTalk] Frequent crankup coax recommendation
>
>> I've got a 30ft three section crankup (AB1342) that I'll be putting up
>> this spring. It will likely be cranked up and down nightly with a
>> hexbeam on top. I was thinking of RG8x for its flexibility for the
>> 20ft resulting loop and RG213 for the run to the mast and the first
>> 10ft.
>>
>> I was wondering if LMR400 (DB version since it will need to be buried
>> for most of the distance) might be a better choice. I was worried
>> about a large diameter coax in such a loop but upon reading the 1"
>> minimum bend radius for LMR400 I'm thinking it may be a good choice
>> afterall.
>>
>> I've never seen any LMR400 except in web pics and a datasheet so I'd
>> appreciate some advice from actual users.
>>
>> thanks
>>
>> jim miller, ab3cv
>> _______________________________________________
>>
>>
>>
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