All, I purchased 200 Hz 5-pole filters for my K3. They work fine except for one oddity: If I set a manual notch at exactly 700 Hz, then sweep the bandwidth control from the maximum of 2.5 KHz to a minimum 0.05 KHz, I would expect the audio to disappear at whatever the notch width is, (Passband <= NOTCH), and stay that way. It does not.
My findings: Between bandwidth settings 2.8 and 0.30 full audio. (FL3 and FL4, 2.8K and 500Hz transitioning at 0.5) Bandwidth 0.25 abrupt total silence, FL4 (500Hz filter) (might have expected this at 0.20 instead) Bandwidth 0.20 total silence, FL5(new 200Hz filter) Bandwidth 0.15 total silence, FL5 Bandwidth 0.10 full audio abruptly returns, FL5 (unexpected) Bandwidth 0.05 full audio, FL5 (unexpected) I would have expected audio suppression at 0.2 KHz and continuing down to 0.05 KHz, when the 200 Hz filter was switched in. The fact the audio resumed when the DSP setting was at 100 and 50 Hz was unexpected. Granted, I would not normally use a notch to separate signals but would tune either high or low of the interfering signal, so this is not really a big deal. I do seem to find the most pleasing CW copy right at DSP bandwidth of 200 Hz but not less. Parameters: Band 10 MHz CW main receiver, K3 F/W MCU v04.51. 73, Dan W6DAS ______________________________________________________________ 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
