Cold shrink tubes

I discovered this technology rather recently on YouTube and I was instantly hooked by the opportunities. I bet most of you who had to insulate connectors or sections of hardware (like antenna segments, for example) relied heavily either on self vulcanizing tape or on electrical insulation tape. Both had disadvantages but for me the deal breaker is how difficult it is to wrap a sticky tape in crammed spaces (imagine trying to isolate a cable and connector assembly one inch away from a wall, in a frosty day). Of course, there are some very bright workarounds (like wrapping some tape around a pencil and then revolving the pencil together with the tape around the fixture), but cold shrink tubes not only that remove those difficulties completely but are almost perfect in what regards weather sealing. For Ham Radio this is a huge advantage because our antennas and fixtures are outside, at the mercy of nature. The disatdvantage is that cold shrink tubes tend to be pretty expensive. I bought some 3M tubes from Mouser (datasheet here) and the price was quite steep for a 6.2” (158 mm) tube (almost $30).

3M cold shrink tube. The one in the picture is 8445-7.5, wich can be used for a minimum diameter of 0.37” (9,4 mm). This model maximum diameter insulation covers up to 0,72”(18,29mm), which I chose to fit PL and N connector diameters.

A cheaper option is to buy similar products from Messi & Paoloni:

The cheaper (and smaller) version from Messi & Paoloni. At €3.77 a piece these are much more affordabe and, probably, without sacrificing the quality. The one in the image above is the “S” (small) version.

These are much shorter and considerably cheaper at €3.77 (apx $4) a piece. You can buy the ones in the image above here. I didn’t test them yet so I cannot judge the differences, but I will for sure post here once I will use them in the field. I considering using the 3M ones to insulate the joints of a X300 Diamond antenna and the ones from Messi for connectors but I haven’t decided yet. On Messi & Paoloni’s website you can find several YouTube videos that show how these tubes are used.

BTW, Messi manufactures. some pretty damn good RF cables that you might consider. I got myself 50 meter of hyperflex that I will use for my VHF/UHF combe that I intend to mount in couple of weeks. On that occasion, I will write another article once I will have some actual experience using these. Stay tuned. Bye

AP