The loss characteristics between RG8X and RG8U on 80 and 40 are not relevant for your purposes.  
The X would be a lot easier to handle and not as heavy.

----- Original Message ----- 
From: Pat Byrne 
To: [log in to unmask] 
Sent: Saturday, April 25, 2015 10:50 PM
Subject: Re: RG8X VS RG8U


Tom,
The "U" will certainly be capable of handling higher power than the 
"X".  And there is probably lower loss in the "U", but i bet you 
would never hear it.  My only concern would be the considerably 
higher weight and drag of the replacement coax.  i have a good run of 
"U" here but have been very reluctant to run it for just that 
reason.  With an antenna in two trees which won't stay in sync. when 
the wind blows is problematic and the added weight of the heavier 
cable could be an issue.
Just my thoughts and good luck on the new installation.
pat, K9JAU At 09:23 PM 4/25/2015, you wrote:
>Hello, everyone.
>
>
>
>This afternoon, A friend and I took down my Alpha Delta DXCC antenna from
>the camp site we used last year, and I'm getting ready to put the antenna
>up at a different camp site that we will be using this season.
>
>
>
>I have noticed that the 75 feet of RG8X coax I have used as a feedline for
>probably the past 1 or two years seems flaky, in that I get a short across
>both of the coax connectors when I check for continuity.  I took off one of
>the connectors that I felt was questionable, and installed a new one, just
>to have the same problem recur.  I am beginning to think that my best option
>might be simply to replace the old coax with something new, rather than risk
>getting the antenna up in the air at the new camp site, only to have a bad
>feed line.
>
>
>
>I have 100 feet of RG8U here, and am considering using part or all of that
>coax run, depending upon how much I will need, rather than buying completely
>new RG8X.  I will have to put connectors on the RG8U if I go this route, but
>that shouldn't be too big of a deal.
>
>
>
>My question is this:  Can someone tell me how RG8X and RG8U compare, for a
>simple HF installation?  Initially, I was going to put the RG8U in my go
>kit, and use it  for emergency VHF/UHF communications, but if it would be ok
>for my HF RV installation, I may just go that route for now.
>
>
>
>Any wisdom on the topic would be appreciated.
>
>
>
>Tom Behler: KB8TYJ
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