[Amps] Sleeve Baluns FS

[Vic K2VCO]

Jim Brown wrote:
> On Sat, 25 Apr 2009 12:04:53 -0700, Vic K2VCO wrote:
> 
>> Jim, I think you missed the statement that the cores are 1-1/8" long.
> 
> No, I didn't miss that at all, Vic. I have cores like that (including 
> some that I bought from Palomar to see what they were selling as a 
> balun). My comments are based on those cores. It is a very poor excuse 
> for a common mode choke. 

They may be made out of a material that's inappropriate for the job. But you said

> 5 cores of any material I know of is woefully inadequate to provide much choking impedance on the HF bands.

and I disagreed, because the number of cores is irrelevant -- it's the total length of the 
cores that counts, not the number. If the usual cores are 3/8" long, these are each worth 
three of them, so five of these cores are the same as 15 of the usual size.

15 cores of #31 material make a pretty decent choke, at least above 3.5 MHz.
-- 
73,
Vic, K2VCO
Fresno CA
http://www.qsl.net/k2vco