[TowerTalk] Terminate braid at top of tower...or

[Jim Lux]

On 11/4/14, 5:38 AM, john at kk9a.com wrote:
> Array Solutions mounts their choke in a small plastic Nema junction box.
> They use small Teflon coax and I believe it is around a single core in
> some of their models. DX Engineering mounts their chokes in a small
> aluminum enclosure.  Cal-Av mounts theirs in PVC tubing. Is heat a big
> concern?
>
>

It depends..
I suspect that in most cases there isn't a big problem, because the 
antenna and coax layout is reasonably well balanced, so the choke works 
effectively and doesn't dissipate much heat.

The vast majority of use by the customers is very low transmit duty 
cycle, so the average power is low.

For the 5% (or 1%) of users who run a kilowatt (or more) in a RTTY 
contest with the yagi twisted sideways on the tower because of the winds 
which are also blowing the coax around, so it's parallel with the driven 
element.  The choke overheats and fails, and the user goes out and buys 
another one and posts a 1/5 review on eham.