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
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