[TowerTalk] Best coaxial to make Chokes

[Roger (K8RI) on TT]

On 11/13/2013 12:07 AM, Jim Brown wrote:
> On 11/12/2013 8:20 PM, Roger (K8RI) on TT wrote:
>> may be wrong, but I've always looked at the solenoid coil as if it 
>> forms two resonances. The choke itself forms a parallel resonant 
>> frequency with a rather high Q So it may work on one or two bands and 
>> it also forms a second resonant frequency with the overall coax 
>> length which can be worse than no choke at all. 
>

True, but I was trying to keep it simple. <:-)) I mean no disrespect to 
anyone, but It at least helps some get a basic understanding that were 
not familiar with the concept.

It's like me, trying to explain what I did for a living (computer 
systems Project Manager).  It didn't take long at all to see that glazed 
look in their eyes.  <:-))  I just tell them I used to head up projects 
like the ACA failure, but mine worked<:-))  If I'd said we expect a few 
glitches, I'd have been out of a job.<LOL>

73

Roger (K8RI)



> That's a good way of looking at it, but also an optimistic one.  The 
> resonance of the solenoid coil (no ferrite core) has a rather high Q 
> (so it's a narrow resonance) and is usually much higher than the band 
> where it needs to work, in which case the resonance is of no value. 
> It's also optimistic that only one resonance will form with the coax. :)
>
> 73, Jim K9YC
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