[TowerTalk] replacing coax on a crank-up

[Craig Clark]

>    1. crank ups and coax (George M. Badger, III)

Hello George et al,

For most HF applications, a good RG213 is more than adequate for feeding 
antennas on a crank-up tower. That said, with my Tri-ex W67, I used Davis's 
Buryflex: since I sell it, why not use it.

I cycled my tower ever year to lubricate the top bearing and eye-ball the 
connections to ensure that they were water tight.  The Bury-flex was up for 
years and showed no signs of degradation from water or UV rays and was not 
damaged when the tower crashed, hi hi.

Standard LMR400 is not the best choice as it has a solid center conductor. 
If you want to use LMR, use UF which has a stranded center conductor. The 
loss numbers on LMR400 and Buryflex are about the same. Bflex is a bit more 
expensive due to its burial grade outer layer of plastic.

When you engineer the coax you have to take in to account the length from 
the shack to the base of the tower and then up the tower. I chose to secure 
the coax and rotor cable to the standoffs so you had to calculate the 
length of each loop. I found this to be better than letting the cable have 
free run.

I ran a low loss coax, 9913, from the shack to the antenna switch at the 
base of the tower. I then ran Bflex to each of the antennas. I had on this 
tower:

Cushcraft:
         X-7
         5 element 6 meter
         19 element 2 meter
         146/440 dual band vertical

I can't imagine using RG214 unless you already have it. Especially if it is 
silver plate. $$$$$

Good luck.


73, Craig Clark, K1QX

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