[TowerTalk] LMR 600 Water-proof Feed Thrus (+ H20 proof'g) DAVIS RF Response

[Gene Smar]

TT:

     The Polyphaser suppressors I installed (IS-B50HU-C0) included an O-ring 
to seal against the outside of the Hoffman enclosure in which they are 
mounted.  If your suppressor didn't come with them, you can probably find 
them ata local hardware store.  No need to use caulking.


73 de
Gene Smar  AD3F


----- Original Message ----- 
From: "jimlux" <jimlux at earthlink.net>
To: "Stephen Davis" <sdavis at davisrf.com>
Cc: <markrob at mindspring.com>; <k4pwo at comcast.net>; <k0dan at comcast.net>; 
"Roger (K8RI)" <k8ri-on-towertalk at tm.net>; <towertalk at contesting.com>; 
<jimljux at earthlink.net>
Sent: Saturday, July 31, 2010 11:00 AM
Subject: Re: [TowerTalk] LMR 600 Water-proof Feed Thrus (+ H20 proof'g) 
DAVIS RF Response


> Stephen Davis wrote:
>> Hi Guys,
>>
>> Some observations: There was a reference to "Silicone Caulk" for
>> sealing the connector threads.  I think he meant Silicone grease.
>> Silicone grease is better for a number of reasons, and  although some
>> folks use Silicone caulk on the outside of connectors, and to seal
>> wire connections from coax to wire antenna feed points, I recommend
>> against it as there can be adverse chemical reactions with copper
>> wire and also silicone caulk will seem to adhere to PVC and PE (many
>> LMR's) outer jacket but in very short time the seal will break down,
>> letting water in.
>>
>
>
> I was thinking silicone caulk to seal the the housing of the transient
> suppressor to the box, not for the threads.. The idea being that you
> drill a hole in the box and push the threaded part of the connector thru
> the hole, with the housing of the suppressor snug up against the inside
> wall of the box.
>
>
> Cheaper and smaller than a bulkhead feedthrough and another cable inside
> the box from feedthrough to suppressor.
>
> Of course, one could probably just use a piece of wire (not coax) to
> connect the center pin of the feedthrough to the center pin of the
> connector on the suppressor.  The shield of the feedthrough is solidly
> connected to the box, as is the housing of the suppressor, and the few
> inches of wire probably wouldn't make much difference impedance wise, at
> least for HF.
>
>
>
> You'd use whatever usual scheme you want for sealing the actual connector.
>
>
>
>
>
>
> _______________________________________________
>
>
>
> _______________________________________________
> TowerTalk mailing list
> TowerTalk at contesting.com
> http://lists.contesting.com/mailman/listinfo/towertalk