I agree with Cookie. Those xtal "roofing" filters become important if you are going toe-to-toe with a lot signals in a pileup but, otherwise, the DSP filters built in do an excellent job in 99.9% of your contacts.
The xtal filters protect the HAGC from being triggered by very signals much, much, MUCH, stronger near enough to the one you are trying to copy that they are inside the xtal filter bandpass. The HAGC must react to protect the 2nd i.f. DSP from being overloaded by cranking down the RF gain levels. But if you don't have that extreme condition they aren't necessary. I am a 99.99% CW op and have found a single 400 Hz CW filter covers all of my needs for routine contacts. I only occasionally get into a DX pileup or other condition where I'm trying to handle a lot of signals almost on top of the one I'm trying to copy. 73, Ron AC7AC -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of WILLIS COOKE Sent: Friday, February 24, 2012 5:21 PM To: Robert 'RC' Conley; [email protected] Subject: Re: [Elecraft] A CW Question for the group At the risk of severe flames, I would recommend that you just try the digital filter that is already there and not buy a CW filter right away. The main function of the narrow filter is to manage a very strong signal that is near your frequency that penetrates the slope of the digital filter, but would be blocked by the steeper slope of the CW filter. It is not like the older analog rigs that without the 500 Hz filter would receive the entire passband of the SSB filter with no filtering of the signals in its passband. If you decide that you want a filter, I would recommend the 500 Hz 5-pole, but if money is no object the 400 Hz 8 pole would also be nice. I am primarily a CW operator and I have the 2.7 kHz 5-pole, the 500 Hz and the 200 Hz. What ever you decide about filters, give CW a go and welcome to the fun mode. Willis 'Cookie' Cooke K5EWJ & Trustee N5BPS, USS Cavalla, USS Stewart ________________________________ From: Robert 'RC' Conley <[email protected]> To: [email protected] Sent: Friday, February 24, 2012 7:00 PM Subject: [Elecraft] A CW Question for the group I am not a CW op! I work mostly QRP phone in contests. Current configuration is K3/10 w/2.7khz filter . I wish to enhance it with 2.1khz, 1.8khz and I intend to purchase P3 and CW filter for use with my K3/P3. I am wondering which one would be MOST USEFUL FOR ME... 8 pole 400hz or 250hz or 5 pole 500hz or 200hz? My CW is very RUSTY but I wish to improve it. I need help help arriving at this decision. So I'm asking the CW op's in the group. Thanks RC KC5WA ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
