Hi Dimitris,
>the mistake I made the first time was that I incorrectly set the ID/OD
>difference of the equivalent ring to be 2 cm instead of 4...
The cross section of the rods or equivalent toroid is 2cm x 10cm.
If you take 10cm as height the ring is 2cm thick.
Hence the OD/ID difference is indeed 2cm not 4cm...
73
Clemens
DL4RAJ
>-----Original Message-----
>From: [email protected]
>[mailto:[email protected]] On Behalf Of
>Dimitrios Tsifakis
>Sent: Saturday, January 12, 2019 8:55 PM
>To: [email protected]
>Subject: Re: LF: RE: Re: a lot of ferrite
>
>Hi Clemens,
>
>the mistake I made the first time was that I incorrectly set the ID/OD
>difference of the equivalent ring to be 2 cm instead of 4...
>
>73, Dimitris VK2COW
>
>Στις Κυρ, 13 Ιαν 2019 στις 1:20 π.μ., ο/η Clemens Paul
><[email protected]> έγραψε:
>>
>> Hi Dimitris,
>>
>> >Minor correction, the calculated relative permeability
>should be about
>> >500,
>>
>> I've made a calculation based on your data with the mini
>ring-core calculator
>> and it says µ = 1070 and AL = 937.5nH /N^2
>>
>> So your first calculation seems to be right.
>>
>> 73
>> Clemens
>> DL4RAJ
>>
>>
>>
>> >-----Original Message-----
>> >From: [email protected]
>> >[mailto:[email protected]] On Behalf Of
>> >Dimitrios Tsifakis
>> >Sent: Saturday, January 12, 2019 5:03 AM
>> >To: [email protected]
>> >Subject: LF: Re: a lot of ferrite
>> >
>> >Minor correction, the calculated relative permeability
>should be about
>> >500, I made a mistake in the initial calculation. I just
>discover why
>> >they call it initial permeability (bad joke) :-)
>> >
>> >73, Dimitris VK2COW
>> >
>> >Στις Σάβ, 12 Ιαν 2019 στις 2:48 μ.μ., ο/η Dimitrios Tsifakis
>> ><[email protected]> έγραψε:
>> >>
>> >> Hi LF group,
>> >>
>> >> I have managed to acquire a few very large ferrite rods (36
>> >cm x 10 cm
>> >> x 2 cm). The material is unknown but I managed to form a square
>> >> 'toroid' with four of them (they are heavy so gravity was
>enough to
>> >> keep everything in place for a measurement) and I measured
>> >about 15 uH
>> >> for 4 turns at 0.1 MHz, which if I have done the calculations
>> >> correctly implies a relative permeability of about 1000.
>> >>
>> >> The R of the impedance of the square loop was low (<0.2
>ohm) at 0.1
>> >> MHz and it increased fast with frequency (170 ohm at 5 MHz!).
>> >>
>> >> The question is, what LF/VLF experiment would you do if you
>> >had half a
>> >> dozen of these rods?
>> >>
>> >> 73, Dimitris VK2COW
>> >
>> >
>> >---
>> >Diese E-Mail wurde von AVG auf Viren geprüft.
>> >http://www.avg.com
>> >
>>
>>
>
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