[TowerTalk] Using Belden 9913 on a crankup?

[Dick Green WC1M]

I would not use 9913 on a crankup tower. It's way too stiff and will bow
out. Over time, the constant bending will cause the center conductor to
migrate, affecting the cable impedance. I initially used the much more
flexible Times Microwave LMR-400UF, but even that was too stiff. I had a
near-disaster when the LMR bowed out, swung around the tower and got caught
on the motor housing (I have a remote-controlled tower and can't see it from
the control position.) Ever since, I've used RG-213 with no problems. That
should be fine on a 50-foot tower. However, some comparisons between RG-213
and Buryflex revealed that the latter is actually more flexible. It also has
much lower loss. You can get Buryflex from Radioware
(http://www.radio-ware.com/).

73, Dick WC1M

> -----Original Message-----
> From: Tower (K8RI) [mailto:tower at rogerhalstead.com] 
> Sent: Monday, April 26, 2004 10:11 PM
> To: coulter at bellsouth.net; towertalk at contesting.com
> Subject: Re: [TowerTalk] Using Belden 9913 on a crankup?
> 
> 
> I used 9913 for years and then gave it all away after one 
> lightening strike blew off the water proofing.  I figured it 
> just wasn't worth the risk.
> 
> OTOH 9913 is not a good cable to use where flexing is 
> encountered.  The center conductor can migrate off center and 
> it needs to make wide radius bends if long life is expected.
> 
> I much prefer LMR 400 to 9913. It's slightly cheaper, or has 
> been. It's one or two tenths of a db less loss and fits the 
> same connectors.  Both fit PL259s. LMR 400 is more rugged and 
> can make relatively short radius bends. Much shorter bends 
> with reliability than 9913. I believe (without taking the 
> time to look it up) that LMR-400 extraflex has about the same 
> loss as regular 9913, but is more expensive.
> 
> I used 9913 for years without a problem, or at least I never 
> noticed any.  I liked it, but finding water running out of my 
> rig after the lightening blew off all the water proofing was 
> enough to cause a rapid switch to something better.  I'd 
> probably still be using it had that not happened.
> 
> You'll also most likely find hams who have used the stuff in 
> flexing situations with no problems (there are usually 
> exceptions to most any set of
> circumstances)
> 
> Good Luck,
> 
> Roger Halstead (K8RI, EN73 & ARRL Life Member)
> N833R, World's Oldest Debonair (S# CD-2)
> www.rogerhalstead.com
> 
> 
> > Could somebody tell me if Belden 9913(not 9913 flex)is usable on a 
> > crankup tower. What I am interested in, is if it is bendable enough 
> > when the tower
> is
> > cranked down or will it bow out too much? Should I go to a more 
> > flexable
> cable
> > for the run up the tower, or is it workable? This is for a 51 ft. 
> > crankup. Thanks for your help.
> >
> >                             Todd
> >                             N4JRZ
> >
> >
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