Message-ID: <27bde532-fdb7-b8b9-d8a7-409d37d8eb52@btinternet.com>
Date: Fri, 12 Aug 2022 00:23:56 +0100
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Subject: Re: [geda-user] Active filter
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To: geda-user AT delorie DOT com
References: <20220811143644 DOT 13DD38248090 AT turkos DOT aspodata DOT se>
 <a45c0258-6812-48ee-bbb1-a5e10983e261 AT btinternet DOT com>
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From: "Roger Burghall (roger DOT burghall1 AT btinternet DOT com) [via geda-user AT delorie DOT com]" <geda-user AT delorie DOT com>
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OK, I have an up to date version that does compile and run. I must 
upload that. Thanks for letting me know.

Regards

Roger


On 11/08/2022 20:44, karl AT aspodata DOT se [via geda-user AT delorie DOT com] wrote:
> Roger Burghall:
>> I've taken an interest in active filters for a while. (Starting in 1971  to be exact!)
>> On GitHub I have the most complex of the programs I wrote to design them.
>> Look for r-burg / rbfilter.
> Ok, got it.
>
>> I don't know if it still compiles several versions of Ubuntu later, it's written in
>> (an early version of) C++.
> ...
>
> No, there are missing libs, they are considered to "old",
> that's the drawback of using gtk et al.
>
> Calc.cpp seems the most interesting one.
>
>> As source material for learning the theory, a long series of excellent articles was
>> published in Wireless World in about 1969 to 1971 and it was archived.
>> Try https://worldradiohistory.com/UK/Wireless-World/60s/Wireless-World-1969-08.pdf to start.
>> Also try "Active Filter Design" by Carson Chen, published by Hayden.
> Thanks, I'll look into that.
>
> Regards,
> /Karl Hammar
>
>
>