[sdiy] question about a Mankato filter

[David Brown]

I didn't see a response to this yet.  I used a 1 KHz square wave and 
adjusted the output (input to Mankato) to 10.0 V pk-pk.

Input:   10.0V pk-pk
   6 dB:   5.0V pk-pk
12 dB:   6.9V pk-pk
18 dB:   9.9V pk-pk
24 dB: 13.7V pk-pk

Yes, your assumptions are correct.

Dave

At 11:53 PM 5/31/2010, David G. Dixon wrote:
>If anyone here owns a Mankato filter, I wonder if you could satisfy my
>curiosity about one small matter:
>
>I understand from the website that when the filter is self-oscillating with
>no input signal, all of the quadrature sine waves have roughly the same
>amplitude.
>
>However, it seems to me that when the regeneration is turned all the way
>down (i.e., no resonance) and the cutoff frequency is turned all the way up
>(i.e., no filtering), then an input signal will be reproduced at different
>amplitudes from the various outputs.  Indeed, an unfiltered +/-5V square
>wave should come out at approximately +/-2.5V from the 6-dB output, +/-3.4V
>from the 12-dB output, +/-5V from the 18-dB output, and +/-6.8V from the
>24-dB output.
>
>If someone could confirm or refute this notion by doing an experiment on an
>actual Mankato filter, I'd love to know the result.  Thanks in advance!