Sujet : Re: Filter problem
De : liz (at) *nospam* poppyrecords.invalid.invalid (Liz Tuddenham)
Groupes : sci.electronics.designDate : 12. Jun 2025, 13:21:23
Autres entêtes
Organisation : Poppy Records
Message-ID : <1rdtgip.nsoyq1furciqN%liz@poppyrecords.invalid.invalid>
References : 1 2
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Bill Sloman <
bill.sloman@ieee.org> wrote:
On 12/06/2025 7:06 pm, Liz Tuddenham wrote:
<snip>
I have some ferrite toroids that could be used to match the valve output
impedance to the filter characteristic impedance.
Do you know the nature of the ferrite in the toroids?
Manganese-zinc ferrites tend to be lossy at frequencies above a few
hundred kHz. Nickel-zinc ferrites have a higher resistance but get
lossy above a few MHz.
If there are specialised ferrites for the 150MHz range I've yet to hear
of them.
They are FT-37-43, which are claimed to be good from 25 to 300 Mc/s.
-- ~ Liz Tuddenham ~(Remove the ".invalid"s and add ".co.uk" to reply)www.poppyrecords.co.uk
Filter problem
Re: Filter problem