Topband: a box of ferrites

Michael Walker va3mw at portcredit.net
Wed May 31 23:26:34 EDT 2017


Thanks All

Sean, I have at least 3 printed opies of W1HIS's pdf and I totally forgot
that was in the back.  It was that article that made me a choke everything
convert.

Hence the reason I have been buying some fleamarket chokes.

Brian, I tried a jig where I would wrap about 8 turns of wire around the
choke and then sweep it with the SpecA and see how many db of attenuation I
got.  I did get results, but I could not confirm if they were accurate.

thanks, mike

On Wed, May 31, 2017 at 10:16 PM, Sean Waite <waisean at gmail.com> wrote:

> W1HIS talks about how to identify ferrites in appendix 1 of this doc:
> http://www.yccc.org/Articles/W1HIS/CommonModeChokesW1HIS2006Apr06.pdf
>
> -Sean WA1TE
>
> On Wed, May 31, 2017 at 9:51 PM Michael Walker <va3mw at portcredit.net>
> wrote:
>
>> This group is clearly one of the most technical groups around and if this
>> off topic enough, please kill it.
>>
>> The question is that if you have a box of ferrites with no labels on them,
>> how could you measure their ability to be used as a choke.  Yes, you could
>> measure them and look them up assuming they came from one vendor.
>>
>> You have the usual ham tools plus a spectrum analyzer with a tracking
>> generator.
>>
>> Does anyone have a tried and true method for determining what their
>> choking
>> impedance might be?
>>
>> Mike va3mw
>> _________________
>> Topband Reflector Archives - http://www.contesting.com/_topband
>>
>


More information about the Topband mailing list