I read through an extensive, several-years-old archived thread the other
day, -- somewhere, maybe on QRZ.com -- on UHF vs. N-type connectors. While
the recent discussion of UHF connector loss at various frequencies has been
very enlightening, the caveat "high-quality, properly installed" is always
stated or implied.
One of the things I read in the aforementioned thread was from a guy who
believed that the PL-259 connector is much better installed in a manner that
differs significantly from the "standard" method. I'm wondering what the
group here thinks of this idea. This is paraphrasing from memory:
"Slip the connector sleeve ring and a length of heat-shrink 2-3" long over
the coax. Strip the outer jacket and center dielectric using the same
dimensions as for the "standard" method, but don't trim the shield braid.
Instead, pull the shield braid inside-out back over the outer jacket. Screw
the connector body over the prepared cable end such that the braid is
compressed between the connector threads and the jacket of the cable. This
will be hard and will require hand tools, but keep screwing it on until you
can just see the braid through the solder holes. You stop there. You don't
solder it through the solder holes, but rather around the rear edge of the
connector body. Then trim off the excess braid and apply the heat-shrink
over the connector body and the cable behind it. Solder the center conductor
and trim off any excess length. Then thread on the sleeve ring."
That's it. I don't recall that the guy said exactly WHY he thought this was
a better method, but after thinking about it, I'm not sure I like it. The
good point is that it would result in less deformation of the dielectric
material by soldering heat. But the shield connection seems problematical to
me. While compression of the braid against the inside of the connector body
would make a good unsoldered shield connection (assuming you were using
good-quality silver plated connectors), that connection would degrade over
time, as the connector is not weather-resistant like the N-type. Soldering
it as proposed in his method, on the other hand, would effectively relieve
the beneficial pressure of the braid against the inside of the connector
body by melting the jacket material. Of course soldering would provide its
own permanent electrical connection to the shield, but only at the back edge
of the body. Because of the squirrelly back-looped path of the shield to the
connector body attachment point, it seems to me that this method would
create even more of an impedance hump that the "standard" method. (Though at
HF, as discussed here earlier, it probably wouldn't matter a hill of beans
one way or the other.)
But I could be completely off the wall here. What do y'all think of his
method?
Bill / W5WVO
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