[TowerTalk] DC-4 or DC-5 ?

kc4pe kc4pe at bellsouth.net
Mon Jul 10 07:54:08 EDT 2017

Don't know..been fighting this battle for 50 years.

If you use a coax that had a a braid then there is no way to really 
waterproof it..

The jacket breaths..

moisture ligates thru the jacket and through the braid.

Litigates through the dielectric

Now moisture on the center conductor, and corrosion.

Now I have tried them all...glued shrink tubing...submerse the whole 
joint connector in wax/paraffin...

The best I have found is:

Prepare a plastic box large enough to hold the connector in and out..run 
12vdc to the box, and install a 12VDC heater, with thermostat and with 
moisture sensor and it all comes with a 1.5 inch fan...  Seal the coax 
in and out with epoxy, and use Hard Line....an ll this can be found at a 
CCTV security shop, this is used in camera housing to do exactly what we 
want to do with coax and moisture.

Second best:

Coast the connector with a dielectric grease and stop, leave it out in 
the elements, it will dry as fast as it retains water..when you tape or 
whatever to cover the connector your are inhibiting it's ability to 
dry...open yearly and re-grease. and use hard-line. The procedure is 
plan and simple but works, have two twos up for 25 years with this type 
connectors assembly...

Bill ...KC4PE

On 7/10/2017 2:34 AM, Roger (K8RI) on TT wrote:
> I've been using these dielectric greases for over 30 years.
> For your use, it doesn't make a difference. Both are essentially 
> dielectric greases, not lubricants although they will serve that 
> purpose. You can even flood the connectors, but be warned that 
> "flooding" has its own problems.  Be careful with Silicones. Nothing 
> will stick to them.  HOWEVER , in the presence of a high voltage arc, 
> both will break down with one of the byproducts being SiO2 (Silicone 
> Dioxide = powdered quartz) a highly abrasive material.
> I used to get a lot of both for a buck a 10 oz tube at the company 
> store.  A 10 oz tube lasts a very long time.
> 73, Roger (K8RI)
> On 7/9/2017 Sunday 11:59 AM, Jim Thomson wrote:
>> Which of the Dow corning products  would be best for coax connector 
>> center pins,
>> and also on the threads of coax connectors ?
>> http://www.dowcorning.com/applications/search/default.aspx?R=402EN 
>> Scroll down a bit to get the pdf file.
>> http://www.dowcorning.com/applications/search/default.aspx?R=12722EN 
>> Pdf file is down a  bit.
>> DC-4 might be better for threads...and DC-5  might be better for the 
>> center pin, dunno, it’s a  little confusing.
>> DC-4 is good for spark plugs, which is hv.   Then DC-5 is made for 
>> HV.  yet the DC-4 has a higher standoff V, 1 kv per mil.
>> DC-5 is  545 V per mil.
>> I also need something to coat  the rubber gasket seals on several 
>> nema-4 boxes which will be outdoors.
>> I might get one of each type, as I can see where this goop would work 
>> on a lot of items used both indoors and outdoors.
>> Has anybody used either of these products...and what application did 
>> you use it ?
>> Jim  VE7RF
>> _______________________________________________
>> _______________________________________________
>> TowerTalk mailing list
>> TowerTalk at contesting.com
>> http://lists.contesting.com/mailman/listinfo/towertalk

More information about the TowerTalk mailing list