[Boatanchors] Choke Info Needed

[Carl]

His meter told him all that was needed.

Keep it up as you usually do with useless blather.

C.


----- 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: Friday, October 09, 2009 11:45 AM
Subject: Re: [Boatanchors] Choke Info Needed


> 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
>>>>>>>
>>>>>>>
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>>>>>>
>>>>>
>>>>>
>>>>
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>>>
>>>
>>
>>
>
>