[TowerTalk] CMC-230-5K

[Jim Brown]

On Thu,4/21/2016 6:42 AM, Jim Thomson wrote:
> Date: Thu, 21 Apr 2016 03:28:00 -0400
> From: "Roger (K8RI) on TT" <K8RI-on-TowerTalk at tm.net>
> To: towertalk at contesting.com
> Subject: Re: [TowerTalk] CMC-230-5K
>
> I don't have any antennas that cover 3-30 MHz so why would I need a
> choke that covers that range? A quickly wound choke for the specific
> antenna is more than sufficient.  Only if you want a choke for all the
> HF antennas you "might" put up would that bandwidth be justified. I do
> have two chokes in series on 75/80.
>
> ###  I only have ONE feedline going up the tower.  The remote switch box is at the
> top of the tower. For this application, for experimental purposes,  I want to be able
> to quickly move the  CMC  from one ant to another to another, so it has to cover at least from
> 160-15m.

Your plan is wrong. A choke is most effective at the feedpoint, not some 
fraction of a wavelength from the feedpoint, as it would be at a switch.

>   I also want to evaluate the effects of cascading both boxes in series, on each of the
> 160-15m  ants.  For this series of tests, it will only see a max of 1200w pep out on ssb..and flat
> swr across each band. So Im not concerned about heating.

Again, don't believe advertising claims about power handling, especially 
from a new vendor with little experience in the application of his product.

>   I also want to try one then both of em
> on the output of the 1200 w amps.

WHY?  There's no common mode at the output of an amp or in your shack 
unless you haven't grounded the coax shield at the entrance. You have 
done that for lightning protection, right?

73, Jim K9YC