----- Original Message ----- From: "Mike Waters" <[email protected]> To: "topband" <[email protected]> Sent: Thursday, June 21, 2012 5:10 PM Subject: Re: Topband: Chokes for Beverages
> Speaking of flooded coax... > > I noticed something recently about at least one of my spools of flooded > quad-aluminum-shield "RG-6". Since the flooding compound is only in the > outer shield (the braid right under the outer jacket), it seems possible > that under certain circumstances, water could still wick its way along the > inner shield and cause degradation of the inner braid and the foil > surrounding the dielectric. > > This could happen if water somehow entered the end of the coax, or damage > (sharp rocks, animal teeth, etc.) to the jacket went all the way to the > inner shield next to the dielectric. Thats how I lost the RG-11 flooded decades ago. After the bites the water went both ways and being the frugal type I checked.... Only short lengths of 10 to maybe 40' were salvagable out of 750' as well as a pair of 200' runs to the relay box. At least they got reused as jumpers around rotators or in the house and yagi stack phasing lines. > > I'm thinking that the aluminum foil shields are plastic coated. I doubt that, it may be a conductive assembly lube. If that's > the case, then only the inner braid would oxidize. Thats where it happens but the white dust is deposited securely to the foil in places. > > In this scenario, the coax would have one intact (outer) braid, and one > oxidized (inner) braid, at least for some distance from where the water > entered. Any thoughts on the consequences if this should occur? A semi conductive jacket between foils or between center conductor and the outer foil. Ive no idea what the results would be. All my feed cables are now elevated at about 6-7' from transformer box back to the switching. This means a 6-7' wire to ground rod 20+ feet from the box ground with 31 ferrites at both sides. > > And is all quad-shield flooded coax manufactured with just the outer braid > flooded? As far as I know. > > If I would have thought of this before, I might not have just laid 600' of > coax on the ground next to a fence. But I haven't noticed anything wrong > with the way that Beverage works (so far). Time and luck will tell. Carl KM1H > > 73, Mike > www.w0btu.com > _______________________________________________ > UR RST IS ... ... ..9 QSB QSB - hw? BK > > > ----- > No virus found in this message. > Checked by AVG - www.avg.com > Version: 10.0.1424 / Virus Database: 2433/5083 - Release Date: 06/21/12 > _______________________________________________ UR RST IS ... ... ..9 QSB QSB - hw? BK
