At 10:41 PM 6/1/2012, Bob Blick wrote:

>Does it get rigid if you hit it with a lot of freeze-spray?

Good thought but it won't work with this particular cable - it=20
remains flexible down to under -55C.  Its probably flexible at=20
temperatures much colder than -55C but that's as cold as the data=20
sheet says.  Its that darned polyurethane jacket <grin>.

The boot I'm using is 2.75" long and can be seen here=20
<http://my.mouser.com/Search/ProductDetail.aspx?qs=3DcnDU2pw5ZgVw1fRf0RNPuQ=
=3D=3D>.=20
Its relaxed diameter is about 0.190" and I need to get it to about=20
0.250" for a short time.

I have lots of different Hellermann (and others) sleeve expanding=20
tools for Hellermann sleeves but they are both too short and not=20
strong enough.  I've been using these sleeves for a several decades=20
now and keep collecting the older 3-prong cast Hellermann expanding=20
tools as I come across them.  I much prefer the old version of the=20
tool compared to the current version being sold today.

Old version that I prefer:=20
<http://www.ventnorradar.co.uk/Lock05a.htm>.  I have several each of=20
4 different sizes.

New version (that I don't much care for):=20
<http://www.google.com/url?sa=3Dt&rct=3Dj&q=3Dhellermann%20tool&source=3Dwe=
b&cd=3D2&ved=3D0CHUQFjAB&url=3Dhttp%3A%2F%2Fwww.canford.co.uk%2FProducts%2F=
55-601_HELLERMANN-SLEEVE-EXPANDER-TOOL-KIT&ei=3Dq1HKT8jOOOi22gXorOzZCw&usg=
=3DAFQjCNEQHRlR2OVjpiHQrW9GWms42QicUg>.=20
I've got a bunch of these that I should just get rid of.

For what its worth, I purchase black Hellermann PH20x20 sleeves=20
10,000 at a time.  Those are 20mm long with an inside diameter of=20
2.0mm.  Can you tell that I like using Hellermann sleeves <grin>?


Someone had suggested using adhesive-lined heat-shrink tubing.  I=20
used to do that but there is still too much flex right at the crimp=20
ferrule.  This leads to shield failure right at the connector.

The Pomona boots are so stiff at the connector that there is=20
absolutely no flex at the ferrule.  They then taper sufficiently thin=20
that the cable flexes in the boot rather than where the cable exits=20
the boot.  The result is that the cables last for many years instead=20
of many months.  The usual failure is mechanical - the cable gets=20
crushed or otherwise wrecked somewhere in the middle of the cable=20
rather than failing at a connector.

Plus: the Pomona boots just look better.

These cables are used by TV broadcast mobile crews and professional=20
football teams for RF intercoms and wireless mics.  They are setup=20
for a single event (mostly sports), then taken down and shipped to=20
the next venue.

Most of the cables I build (many hundreds) are made with the stiffer=20
LMR-240 type cable.  There is simply no problem getting the boots on=20
that cable - a few drops of Hellerine lube and they twist and slide=20
right on.  But I use the super-flex cable for the coaches comms used=20
by professional football teams because the people setting up the gear=20
are not technically-trained and they have real difficulties in=20
working with the stiff cable that I prefer to use.  Thus the use of=20
super-flex cable.

Keep the ideas coming!

Many thanks!

dwayne



--=20
Dwayne Reid   <dwayner@planet.eon.net>
Trinity Electronics Systems Ltd    Edmonton, AB, CANADA
(780) 489-3199 voice          (780) 487-6397 fax
www.trinity-electronics.com
Custom Electronics Design and Manufacturing

--=20
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