Great product but watch mounting

My LNB Samsung was oxidized after 10 years of trouble-free use), I changed to a PSI 0.2dB LNB (sold at Bricorama).
The gain in reception was real (200 instead of 165 cube on C + in Paris), but the reception was interrupted by rain.
This solved the LNB Inverto bp (and the signal is mounted 220).

It was perfect except that one year later, the head is the cable are oxidized.
The water came from the head itself (I had sealed connector).

After analyzing the cause I've realized that the head was designed to protect the connector: once the screw connector, pull a kind of drawer that covers the connector so that it does not sit exposed to rain, but remains open to prevent oxidation.
Now I mounted my connector as I always do, with an exchange cap, it fixed on what is actually the drawer protection that I have not seen (so not deployed).
As a result, moisture is input by the drawer that is not sealed and oxidized cable.
Amazon offering the bundle + cap head, I'm not suspicious to me.
In fact, do not use the connector cap and leave in the open, just protected from rain.