On Sun, 2008-06-01 at 07:01 -0500, Lyle Dunlap wrote:
> Been quite a discussion on connectors, does anyone know if there was a
> specific reason for the making and/or developing of RG87A? And then its
> demise.
>
> One could be cost of course but since it was used and then given up by one
> branch of the military I doubt that. One reason I heard it was too lossy on
> UHF. The center conductor, silver plated, stranded, similar to RG 8 or 214,
> etc. in size then solid teflon, then two silver plated shields, teflon
> wrapping and then a fiberglass outer cover.) (50 or 52 ohms impedance)
> Slightly larger in dia than RG-8 but UHF connectors could be used.
>
I think cost and the solid teflon that size made it stiff. It was used
in a fantasy article in QST once feeding an HF dipole when RG-8 cost a
dime a foot, it cost several bucks a foot. Seems to me I have a length
of it with coax connectors on the ends. It would be handy at power
levels and frequencies where RG-213 or RG-8 can't stand the heat.
Lots of classic RG specs have been abandoned by the military, either to
reduce their number or to incorporate new designs and materials.
> I used some outside to feed 20 and 40 M beams for years living in Hawaii but
> I did give the fiberglass covering a coat of varnish. Must of been intended
> for inside use. Just curious if someone knows the story of this coax cable.
> Rather curious is all.
>
I have an 80m inverted V fed with the miniature single shielded version
RG-141. Size of RG-58. Its gone intermittent, I don't know if its
feedline or antenna or connections. Most of the fiberglass has blown
off. It's not handling outside and dangling well.
RG-142 is the double shielded RG-223 version made of Teflon and silver
plated copper.
> Lyle W9FCX
73, Jerry, K0CQ
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