[Elecraft] BL2 choking Impedence measurements?

[Jim Brown]

On Mon, 30 Aug 2010 20:02:09 -0700 (PDT), Chuck - AE4CW wrote:

>I've recently been using snap-on Fair-Rite part number 0431176451.  It has
>impedance characteristics very similar to the largest snap-on (1" opening)
>but with a 0.7" opening and about 40% the cost.  Arrow had them for less
>than $6 but is out of stock now.  It plenty big enough for multiple turns of
>smaller cables including RG-8X.  Have you tried this one?

I don't recall for sure if I measured that particular core, but I have 
measured at least one core a bit smaller that the "biggest" and it performs 
quite well, and is quite suitable for the uses you suggest. The important 
things are the length (you want it long) and the diameter (you want to be 
able to get enough turns through it). One of the cores I recommend for group 
purchases is one that is about 0.5-in i.d., primarily because it's a good fit 
for winding multiple turns of noisy computer and power supply cables through 
it. 

So yes, as long as you're sticking with #31 material for the low HF bands and 
either #31 or #43 for the higher HF bands and VHF, you're in good shape. 

73, Jim Brown K9YC