Just a note about heat shrink tubing:
It varies widely in dimensions and quality. The cheap thin stuff is usually
pretty fragile. It also comes with and without flooding compound (Hot melt
glue) which for most cases is easily removed to the point of reusing
connectors. No, it's unlikely they will come out looking like new as some of
the glue will probably stay behind. With practice they can come out pretty
clean and the surface will look like new (most of the time).
It would be interesting and beneficial for people to try the tubing from
various sources and then post the results. Most likely there is some out
there that is as good as the MMM for less, but we won't know until some one
finds it.
The MMM tubing is strong and rugged. Even shrunk onto the outside of a
PL-259 it will form a jacket considerably thicker (and stronger) than the
RG-8, LMR-400, or 9913 jacket. It also will make a splice that is more rigid
than even LMR-400, so don't make a splice where you plan on making a tight
bend. Of course the connectors would prevent that anyway. It's *relatively*
easy to remove by slitting the jacket length wise and then using a pair of
pliers to pull it apart. Unlike the stuff from Radio Shack it will not
easily melt, but like anything else it does take a bit of practice to apply
correctly. You can ruin it with heat but if it gets hot the coax inside will
probably be ruined as well. With that practice the MMM material may be
applied with just a straight heat gun and no special attachments. I use a
flat nozzle about 1/4" by about 1" wide most of the time and apply the heat
alternately from points 180 degrees apart. The MMM tubing is fairly
forgiving so the user doesn't have to heat each side precisely the same to
get it to look uniform. Actually you can shrink one side all way way down
and then switch to the other making sure it is shrunk as well. Then shrink
the next section starting with the opposite side and it'll still look good.
Remember how hot, hot melt glue gets. That is how hot you get this stuff to
shrink. Don't get the glue on you as it hurts like the devil and it won't
let go. If you try to pull it off with unprotected fingers you will burn
them too. Please don't ask me how I know<:-)) Tis a good idea to wear good
quality, tight fitting, leather gloves.
For splices I use 3 pieces. The first are about 1 1/2 inches long (Inch to
inch and a half is fine, it's not critical) and applied over the rear of the
PL-259 up fairly close to the rear of the threaded portion which is slid all
the way forward. As long as it covers half the rear of the connector it'll
work fine. This makes a good mechanical connection between the barrel and
the coax jacket IF the metal is clean. I slip a piece over one coax long
enough to extend about an inch beyond the first layer of heat shrink tubing
and onto the coax jacket at each end of the splice. I start in the center
with the heat gun over the double female connector and work out to each
end, one direction at a time.
BTW I've mentioned using DC-4 or 5 as a flooding compound *IN* connectors.
AFTER the first piece of heat shrink is applied to the rear of the
connector, take the tube of DC-4 (or what ever you have is called) and slip
the end over the center pin of the PL-259. Squeeze out enough compound to
form about an 1/8" layer over the insulator in the connector and then
install normally. Be careful about getting any excess on the coax jacket or
your hands. It is Silicone and nothing will stick to in...EXCEPT dirt! If
any thing prevents reusing the connectors it will probably be dirt in the
flooding (DC4) compound and the stuff acts like a dirt magnet. So don't drop
the end of the coax into the dirt or grass after taking it apart. The reason
for applying the compound after the first piece of heat shrink is applied to
the connector is this keeps the threaded portion from slipping back onto the
connector and exposing the grease.
73
Roger (K8RI)
> John,
>
> Harbor Freight also carries the shrink wrap.
> http://search.harborfreight.com/cpisearch/web/search.do?keyword=heat+shrink&Submit=Go
>
> They have some small assortments, a larger (48" pieces) assortment and
> even
> a marine assortment.
>
> 73,
> Scott W5LSU
>
>
> On 8/23/07, fraz1 <fraz1@bellsouth.net> wrote:
>>
>> Hi folks.............any recommendation for a good heat gun to be used
>> for
>> shrink wrapping would be appreciated. Also, good known sources for
>> shrink
>> wrap itself.
>>
>> 73 John K4NP
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