Paul, The Yaesu hardware-based APF design resulted in essentially constant bandwidth of about 30 Hz (6 dB points) and a peaking gain from 7.5 dB to 10 dB depending on its peaking frequency (200 Hz to 1 kHz).
The present K3 APF we're testing has a constant bandwidth of 30 Hz at the 6 dB points and constant 9 dB of peaking gain. It is an IIR filter, closely mimicking a hardware approach. 73, Lyle KK7P > I believe the FT-1000/D's APF had a minimum Q of 10 at the lowest F setting, > then progressively increased to about 30 at the highest setting. ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
