The reason why an RG8X insn't raccomandable at high power levels is
because of a shield that's made of a thin aluminum Foil-Polyester Tape-
Aluminum Foil and only very few thin copper wires as braid shield.
The foam dielectric hasn't significant losses and a foam cable of the
same size of an RG8X, but with a classic copper braid or a more
consistent foil (aluminium or copper), would safely withstand much more
than US legal power at 7 MHz, and roughly twice the power of an RG58
expecially at 30 MHz and above.
73,
Mauri I4JMY
> ---------- Initial message -----------
>
> From : owner-towertalk@contesting.com
> To : <towertalk@contesting.com>
> Cc :
> Date : Thu, 1 Mar 2001 08:35:18 -0500
> Subject : RE: [TowerTalk] Coax Rating
>
>
> Ted,
>
> Be careful. Yes, I have had a meltdown as you call it, using some
> hamfest-grade RG8X on a 100 ft run feeding a 1/2 wave on 40. The
power into
> the feed line was likely about 700W. I don't know whether this
happened
> while operating on 40 or 15. And here's the caution...you might
squeak thru
> with a perfectly flat SWR. But with 3/2 waves I'd bet you will not
have
> that. Any SWR will significantly increase the probability of zapping
the
> line.
>
> As I recall, the rating is about 300V across that foam dielectric.
Less
> sure of that than the above. I believe RG58 is actually more
forgiving than
> RG8X in terms of power handling.
>
> I'm using RG8 now, with a convenient tree to help support the weight
so the
> antenna doesn't have to see it all.
>
> 73/Gary W2CS
>
>
> | -----Original Message-----
> | From: owner-towertalk@contesting.com
> | [mailto:owner-towertalk@contesting.com]On Behalf Of Ted & Joyce
Wilhelm
> | Sent: Wednesday, February 28, 2001 11:39 PM
> | To: towertalk@contesting.com
> | Subject: [TowerTalk] Coax Rating
> |
> |
> | Am planning on trying to put up 3 1/2 waves on 40mtrs. and wonder
if
> | anyone knows the maximum power that RG8X will handle on a relatively
> | short run less than 100 feet....I know I would probably be better
off
> | with something like 213 or the like but am concerned with the weight
> | factor....Anyone had any major meltdowns using the lighter feed
line.
> | Thanks,
> | Ted K9HUH
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