There should be another part to this discussion that I have not yet seen
mentioned. Coefficient of Thermal Expansion.
If the connectors are water tight/air tight, then in theory no taping of
connectors should be necessary if the connections are all
electrically/mechanically sound and very tight (I fill in all four PL259
braid holes with completely melted and flowing solder) and no large
physical stress in placed on them. Furthermore, if tape is used and
water manages to get in, then it can potentially be sealed which over
time could create problems. But changes in heat/humidity can cause
condensation INSIDE the wraps anyway. So not using anything to wrap the
coax/connectors would allow immediate exposure to the elements and
simultaneously allow for moisture drainage away from the
coax/connectors.
But none of that addresses HOW and WHEN those physically tight
connections might become less tight. Enter Coefficient of Thermal
Expansion.
We all know that various metals get hot faster than the outer jacket of
coax, in response to direct sunlight and hot ambient temperatures in the
Summer. Conversely, we know that objects (like connectors) will shrink
in size response to the cold more than coax will shrink because of
differences in the Coefficient of Thermal Expansion (the reverse of how
they all expand with an increase in temperature).
Because connectors will shrink more in response to colder temperature
than coax will, a tight connection will begin to loosen and will allow
for water to get in. This is especially true in Winter in more Northern
climates.
So that "waterproof" connection becomes non-waterproof. And if water
can get in, ice can form and expand the gap and damage the the coax or
connectors or both. By using tape and sealant we are already protecting
against that.
But note that this is already happening anyway in microscale because the
coax jacket and the connectors are neither perfectly smooth nor exactly
the same shape, so there are already tiny ridges and depressions on the
surfaces of the coax jacket and the connectors that are allowing air and
moisture to get in even though you can't see it. But these tiny gaps
can easily be seen under an electron microscope even though is not
visible to the naked eye. Bottom line: Pro or not, you really should
use some sort of quality tape/wrap anyway on ANY connections, including
around connectors.
73
Bob, KQ2M
On 2024-03-09 18:51, Steve Maki wrote:
Gary,
Thanks, I was debating whether to start from scratch again with a post;
whew.
I'll just add that a two layer system can work, IF the stretchy
weatherproofing layer is not the type that gums up the works (the
connector) such as butyl rubber or coax seal. Use a silicone tape 1st
layer with almost any type of good UV protection on top.
If you insist on using the gummy sticky stuff, use it in a three layer
system with a 1st layer of courtesy wrap made of almost anything. The
gummy sticky stuff should extend well past the end of the courtesy wrap
so that that it bonds to the coax. Commercial weatherproofing is almost
always three layer.
-Steve K8LX
On 03/09/24 7:00 PM, Gary NA6O via TowerTalk wrote:
Lots of chatter indeed… Here is my famous summary of all the
weatherproofing methods I noted as of a few years ago. Read and enjoy.
https://na6o.com/amateur_radio/ewExternalFiles/Connector_Weatherproofing.pdf
Gary NA6O
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