[Boatanchors] Choke Info Needed

[J. Forster]

Charts are useless if you don't know the specs on the choke, as was the
case w/ the OP.

-John

================


> Unecessary waste of time since there are graphs in many handbooks that
> tell
> all that is needed to build a successful PS..
>
> Carl
>
>
> ----- Original Message -----
> From: "J. Forster" <jfor at quik.com>
> To: "Carl" <km1h at jeremy.mv.com>
> Cc: "List Boatanchors" <boatanchors at mailman.qth.net>; "Kenneth D. Grimm,
> K4XL" <grimm at sbc.edu>
> Sent: Thursday, October 08, 2009 11:18 PM
> Subject: Re: [Boatanchors] Choke Info Needed
>
>
>> Characterizing is measuring the incremental inductance as a function of
>> bias current. That is essential information to calculate the impedance
>> of
>> the choke vs. current and hence the regulating effect when used as a
>> swinging choke.
>>
>> Apples and apples.
>>
>> -John
>>
>> ================
>>
>>
>>
>>> Characterising is not the same as confirming the static inductance.
>>> Dont
>>> mix
>>> apples and oranges.
>>>
>>> Carl
>>>
>>>
>>> ----- Original Message -----
>>> From: "J. Forster" <jfor at quik.com>
>>> To: "Carl" <km1h at jeremy.mv.com>
>>> Cc: "Mark K3MSB" <mark.k3msb at gmail.com>; "List Boatanchors"
>>> <boatanchors at mailman.qth.net>; "Kenneth D. Grimm,K4XL" <grimm at sbc.edu>
>>> Sent: Thursday, October 08, 2009 7:35 PM
>>> Subject: Re: [Boatanchors] Choke Info Needed
>>>
>>>
>>>> If you want to characterise a swinging choke, a single point
>>>> measurement
>>>> at zero bias current is insufficient.
>>>>
>>>> There are bridge configurations that allow inductance measurement vs.
>>>> current bias, just as there are to measure capacitance as a function
>>>> of
>>>> bias voltage.
>>>>
>>>> Some of the older GR bridges include this feature. I think the 1650s
>>>> did
>>>> for example.
>>>>
>>>> -John
>>>>
>>>> ==============
>>>>
>>>>> Chokes are specified at no load in most catalogs. All the known ones
>>>>> Ive
>>>>> measured with a handheld LCR meter ar right on.
>>>>>
>>>>> Carl
>>>>> KM1H
>>>>>
>>>>>
>>>>> ----- Original Message -----
>>>>> From: "J. Forster" <jfor at quik.com>
>>>>> To: "Mark K3MSB" <mark.k3msb at gmail.com>
>>>>> Cc: "List Boatanchors" <boatanchors at mailman.qth.net>; "Kenneth D.
>>>>> Grimm,K4XL" <grimm at sbc.edu>
>>>>> Sent: Thursday, October 08, 2009 6:36 PM
>>>>> Subject: Re: [Boatanchors] Choke Info Needed
>>>>>
>>>>>
>>>>>> Did you measure L as a function of current through the choke? It
>>>>>> does
>>>>>> not
>>>>>> sound like it.
>>>>>>
>>>>>> -John
>>>>>>
>>>>>> ===============
>>>>>>
>>>>>>
>>>>>>> Well,  I checked again and came up the same info.
>>>>>>>
>>>>>>> I was looking for a 4-12 H 300 mA swinging choke, and a friend of a
>>>>>> friend said he had one, and I picked it up last night.
>>>>>>>
>>>>>>> It's about 18 ohms DC resistance,  and the inductance measures
>>>>>>> around
>>>>>>> 2H
>>>>>>> (using the bridge on my IT-28,  which isn't too bad surprisingly).
>>>>>>>
>>>>>>> Since inductance is inversely proportional to current in a swinging
>>>>>> choke, I don't think what I have is a swinging choke.
>>>>>>>
>>>>>>> Mark K3MSB
>>>>>>
>>>>>>
>>>>>> ______________________________________________________________
>>>>>> Boatanchors mailing list
>>>>>> Home: http://mailman.qth.net/mailman/listinfo/boatanchors
>>>>>> Help: http://mailman.qth.net/mmfaq.htm
>>>>>> Post: mailto:Boatanchors at mailman.qth.net
>>>>>>
>>>>>> List Administrator: Duane Fischer, W8DBF
>>>>>> ** For Assistance: dfischer at usol.com **
>>>>>>
>>>>>>
>>>>>> This list hosted by: http://www.qsl.net
>>>>>> Please help support this email list: http://www.qsl.net/donate.html
>>>>>
>>>>>
>>>>
>>>>
>>>
>>> ______________________________________________________________
>>> Boatanchors mailing list
>>> Home: http://mailman.qth.net/mailman/listinfo/boatanchors
>>> Help: http://mailman.qth.net/mmfaq.htm
>>> Post: mailto:Boatanchors at mailman.qth.net
>>>
>>> List Administrator: Duane Fischer, W8DBF
>>> ** For Assistance: dfischer at usol.com **
>>>
>>>
>>> This list hosted by: http://www.qsl.net
>>> Please help support this email list: http://www.qsl.net/donate.html
>>>
>>>
>>
>>
>
>