[TowerTalk] RG-304 for CMC ?

[Jim Brown]

On Sun,4/24/2016 9:35 PM, Jim Thomson wrote:
> ##  Bunched up loops  lowers  res freq.
Right.

>    Depending on choke  config, it can narrow the range of the choke,

Not if the core material is #31 or #43.


> to the point where it covers 80m  with high  5-6 k RS... but not 40m.
> Lousy on 40m, like 650 ohms.    This appears to be the case  when  Binoc
> config is used in some cases.   With binoc config, with torroids at the 9 +
> 3  oclock positions, the turns all end up bunched  together for the entire loops.
> Bad news  if  LMR-400 /213-U /393  coax used.   A LOT more C  between turns
> with the .405 OD cables...vs  58-U / 303 etc.

This is nonsense.

>
> ##  One  advantage to binoc config, is you can then wind in 1/2 turn increments, like
> 4 -  4.5 – 5  - 5.5  etc.

This is also nonsense. Chokes wound for the HF bands using #31 and #43 
material have VERY low circuit Q, typically on the order of 0.4. This 
makes them broad as a barndoor!  Their tuning is NOT critical.

>
> ## 12 inch diam loops is a trick to maintain spacing between each loop.   With loops
> equally spaced around the cores, now you end up with a mess that is almost 2 foot in diameter,
> which is exactly what I dont want for a cmc...esp on a 80m rotary dipole, mounted 10 ft up
> the mast.     8.5 K in a little box, on 80m, with the CMC-230-5K is a more elegant solution.
>
> ## 12 inch diam loop = 3 ft in circumference.  7 turns = 21 ft of  LMR-400..which is a lotta
> weight,bulk,windload, etc.  But it does provide outstanding high Z / RS  across 80+ 40m..and
> 160m.

I don't know where you get this stuff, but it's nonsense.

73, Jim K9YC