[SixClub] Recommended Coax?

[Roger (K8RI)]

When it  comes to 9913, (the quasi air core type) I threw out and gave 
away over 1500 feet of the stuff and wouldn't use it for a door stop.
The foam filled is fine.  I used to belong to the group that said if you 
seal and water proof the connections it'll be fine. Then lightning hit 
the tower.  It removed every bit of water proofing up there.  In less 
than 15 minutes I had water running out of the 2-meter rig. The rig 
survived, the desk top did not.

On 6/16/2010 2:42 PM, kd4e wrote:
> Based on this site:
> http://www.ocarc.ca/coax.htm
>
>    
I can only get part of that page to work and 9913 is not among the 
choices for the calculator.
Typically the loss between 9913 and LMR-400 is negligible with LMR-400 
costing less.
> Belden 9913 is a better brice-performance choice
> than most,
The prices must have changed as when I put in the LMR-400 it was head 
and shoulders above 9913 with about the same loss and much less expensive.
> except for Andrews Heliax, based on
> loss at 100' but at 150' it changes a little.
>
>    
Of the small cables the 1/2" Heliax has by far the least loss, but it's 
not tolerant of tight turns.  LMR-400 can make a 1.5" radius (Non 
repeatable) bend without the center connector migrating. It's also more 
rugged when it comes to getting stepped on, or run over. It's also 
easier to install on the inside of the tower without worry of kinking. 
But other than that it's the best performer of the bunch. However don't 
forget the cost of connectors. A pair of them for 1/2" Heliax will buy a 
100' of LMR-400 plus connectors. OTOH those connectors and the cable can 
often be found as surplus or pull outs...unless I'm looking for some.
> Variables:
>
> 50MHz
> 100'
> SWR 1:1
>
> ........................Loss100'..Loss150'
> ---------------------------------------------
> Belden 9913..............0.885....1.328
> Davis RF Bury-Flex.......1.009....1.513
> LMR 400..................0.865....1.297
> Andrews LDF4-50A.........0.464....0.696
>
> What am I missing, please?
>
>    
9913 and LMR-400 are nearly identical in loss with only 0.02 db 
difference with LMR being the better.  LMR-400 is usually cheaper than 
9913 and far more rugged and will make tighter turns without the center 
conductor migrating.
As I said, I'd not use the regular, quasi air core 9913 for a door 
stop.  It makes a good water pipe.
The foam filled 9913 is a good coax, but more expensive the last time I 
priced them.

73

Roger (K8RI)