[TowerTalk] Ultraflex coax questions

[Dick Green WC1M]

I started out with LMR400UF on my MA770MDP and found it to be quite stiff.
It had a tendency to bow out from the tower on the way down. That resulted
in a large loop migrating to the other side of the tower and getting hung up
in the motor mounting bracket. When this happened, the tower oscillated like
crazy as the motor tried to fight the snag. I think one or both cables would
have failed had it not been for the antenna balun exploding and releasing
the coax. 

This wasn't entirely the fault of the LMR400UF. The tower really needs one
more standoff below the motor to prevent it. I've since added one and the
coax doesn't migrate anymore.

Nonetheless, I replaced the LMR400UF with Davis Bury Flex and have found it
to be much more flexible and the jacket is more slippery to boot.

73, Dick WC1M

> -----Original Message-----
> From: Howard W6HDG [mailto:W6HDG at arrl.net]
> Sent: Monday, December 15, 2014 11:41 AM
> To: towertalk at contesting.com
> Subject: [TowerTalk] Ultraflex coax questions
> 
> Hi all.  I am about to order about 110 feet of coax for a new
> MA770MDP tower/ Steppir DB18 install.    I'm thinking of using either
> genuine LMR400 Ultraflex or Davis Bury Flex coax.
> 
> Davis BuryFlex is cheaper and I understand it has a tougher and more
> slippery jacket for crank up/down use?   Opinions?
> 
> I am going to try crimp-on RFU-507SI RF Industries PL-259's for the first
time.
> For the center conductor crimp, I have alternatively
> heard of .118 and .128 crimpers being used.   I have the dies for
> both .118 and .128 as well as the .429 braid crimp.  Any opinions? Do you
use
> any dielectric compound such as STUF inside the PL259 to inhibit
corrosion?
> 
> Tnx, Howard W6HDG
> 
> 
>