> Anyone have experience with 1.8 and 2.1 kc filters for the K3? > Trying to decide which one to get.. > > I am a DXer exclusively......not a contester... > work CW rarely.... > > > Does the audio from 1.8 sound too pinched....? > I just dont want to hear a 59+10 signal that is 3 kc..from > the frequency I am listening on.... > > any thoughts? on what filters to get..
Don't commit to any optional filters until you actually use your K3 and determine what bandwidths work best for your preferred operating scenarios. The stock 2.7 kHz filter provides excellent roofing filter protection for the DSP which is where you set your receive bandwidth. Try different SSB receive bandwidths and see what you like. I almost always use 1.6 kHz for SSB and do not find it at all "tinny" or "too narrow" in the K3 as some other replies are indicating. In most other radios, 1.6 kHz far too narrow, at least for me to copy easily. The K3, however, sounds beautiful at these narrow bandwidths. Don't make a K3 crystal filter decision based on experience with other radios, especially someone else's experience with other radios! The easiest way to narrow the bandwidth on SSB is to reduce HI CUT. Until you reach a bandwidth of about 1.5 kHz, you don't need to adjust LO CUT or anything else. This reduces bandwidth while moving Fc down with it. Effectively, adjusting only HI CUT simultaneously adjusts WIDTH and SHIFT ideally for SSB. This is far easier than adjusting WIDTH, then SHIFT to get the sound right. You can slide between 2.0 and 2.7 kHz to see how narrow you can go for the sound you want. So, assuming you have the stock 2.7 kHz crystal filter, and have told the K3 it is 2.7 kHz wide, start there and reduce HI CUT from 2.7 kHz to 2 kHz. LO CUT will remain at 200 Hz and you will end up at a bandwidth of 1.8 kHz. I think you will find that it sounds fine. I prefer these narrow bandwidths because they take out the highs between 2 and 3 kHz. I think this is more intelligible (in the K3) for communications. So-called "hi-fidelity" is something else. Once you get a feel for the narrow SSB receive bandwidth you like, then select a crystal filter that is outside that bandwidth, if you are worried about strong nearby signals interfering with the DSP's ability to provide the listening bandwidth you want. The Elecraft/INRAD 1.8 kHz crystal filter is actually about 1.9 kHz at the -6 dB points, so it won't affect your DSP bandwidths much at 1.7 kHz or below. If that's too narrow for you, then consider the 2.1 which will allow you to get to 2.0 kHz or lower since it is actually about 2.2 kHz. 73, Ed - W0YK _______________________________________________ Elecraft mailing list Post to: [email protected] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
