[RFI] New Larger Fair-Rite #31 Toroid

[Dave Cole]

Thank you Jim!

73s and thanks,
Dave
NK7Z
http://www.nk7z.net

On 04/14/2017 11:33 AM, Jim Brown wrote:
> On Fri,4/14/2017 10:26 AM, Dave Cole wrote:
>> Jim,
>>
>> A question for you...  Looking at the "Impedance vs. Frequency vs.
>> Turn count" graph at:
>>
>> http://www.fair-rite.com/product/round-cable-emi-suppression-cores-2631814002/
>>
>>
>> It looks like these new cores only have two or three K of impedance
>> with  five turns...  Am I interpreting this correctly?
>
> Yes.
>
>>
>> If so, then using two of them with five turns becomes the standard if
>> I want more than five K impedance?  Is that true?
>
> The number of turns (and to to the extent that it affects capacitance,
> wire size and spacing) sets the resonant frequency. The Fair-Rite data
> is most likely for small diameter wire. If you want the choke to be
> effective where 5 turns puts it, yes, two chokes in series would be the
> way to get there. A choke wound with RG8/11 size coax would have the
> same inductance but more capacitance between windings if those windings
> are closely spaced, so the resonance would be a bit lower.
>
> And, of course, more turns will lower the resonance even more, and
> because R also increases with N-squared, also raise the impedance.
>
> 73, Jim K9YC
>
>>
>> 73s and thanks,
>> Dave
>> NK7Z
>> http://www.nk7z.net
>>
>> On 04/14/2017 09:53 AM, Jim Brown wrote:
>>> Yesterday, I got a quote on this part from Dexter, a vendor that has
>>> been competitive for past orders. They don't have stock, minimum order
>>> is a full box, which is 25 pieces, $15.18 each. 50 pieces is $14.27
>>> (-6%). 100 pieces is $13.57. Delivery was quoted as 14 weeks.
>>>
>>> 73, Jim K9YC
>> _______________________________________________
>> RFI mailing list
>> RFI at contesting.com
>> http://lists.contesting.com/mailman/listinfo/rfi
>>
>
> _______________________________________________
> RFI mailing list
> RFI at contesting.com
> http://lists.contesting.com/mailman/listinfo/rfi