> It bothers me that 9913 coax gets a bum rap in the amateur radio
> field. I personally have used a 130' run for over 15 years to feed
> one tower and to date, there is no moisture in the cable. The key to
> use is proper waterproofing which is in the realm of all amateur's
I knew some one would comes to 9913's defense, but "to me" there is no such
thing as proper water proofing for it. Certainly there are going to be more
happy users than dissatisfied, but to me it only takes once.
> capabilities. The same holds true of Davis's Buryflex which has a
> foam dielectric. (Or any other coax for that matter.) You need to
> properly weather seal the connection to make sure water stays where
> it belongs, outside the coax.
> FWIW, I have never had a customer either complain or return a 9913
> order for or due to water ingress.
I had multiple runs of 9913 and all carefully waterproofed. They were up for
quite a few years with nary a problem and the stuff was still bright and
shiny inside. (I checked) Then one day we had a thunderstorm. Lightning
hit the tower and blew off every bit of water proofing at the top. Less than
15 minutes after the strike I had water running out of one rig onto the
operating desk. As soon as the weather broke I was removing coax and
replaced it all with LMR 400. I threw away nearly 800 feet of 9913 and
will never use the stuff again.
You could do the perfect job waterproofing connections, but the potential is
there if something causes that water proofing to fail, be it mother nature
or critters (two or 4 legged). That potential and the one failure makes the
cost of trusting it far too great.
> Any combination of tape, liquid tape, self vulcanizing tape, duct
> seal, coax seal or Scotch-kote, to name a few products, will ensure
> water stays out of your coax.
Nothing can ensure that if it loses its integrity.
My choice for coax would be the flooded (buriable) LMR-600 were I still
working and I may go that route with just two runs and remote switches.
Unfortunately due to multiple stations operating at the same time I would
still need a minimum of four runs at 200 feet each just to reach the top of
the tower. The costly part is each run takes 5 connectors at roughly $25 USD
We're not even in an area considerd as a high lightning hazard, but my
current tower still gets hit on average of three times a year. I have five
confirmed for this year. All ocurred early in the summer. These are
confirmed strikes. How many times it actually gets hit, I don't know but
it's most likely more than the number visually confirmed.
I would note that the connectors on the coax and remote HF antenn switch
appear to have been etched from electrical discharge. The thing is about 4
years old and looks as if it's been up there for 20 years. There's no coax
seal left up there, but *most* of the liquid electrical tape is still in
place. Had the current cables been 9913 instead of LMR 400 I'd already be
replacing it again, or rather I'd probably have been doing so the first
Roger Halstead (K8RI and ARRL 40 year Life Member)
N833R - World's oldest Debonair CD-2
www.rogerhalstead.com (Use return address from home page)
> 73, Craig Clark, K1QX
> RADIOWARE AND RADIO BOOKSTORE
> PO BOX 209
> RINDGE NH 03461
> 603 899 6957
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