> Now that the time has come to chose filters, which ones will > you get? What are people doing? The easiest is to outfit > both receivers with five filters each. With that money, you > can buy another radio. Will you put a wide and narrow > filter in each radio? I primarily use CW, but do both CW and > SSB contesting. Do you outfit one RX with CW filters and the > other with SSB? Or do you make one RX the wide filter and > the other the one with the narrow filters? I think I might > go with the standard SSB filter, the 400Hz, and either the > 1.8 or 2.1K. What is everyone else doing?
The K3 is an outstanding, extremely competitive radio with NO additional filters beyond the included 2.7KHz. Take the Icom 756ProIII as a comparative example. The ProIII is an excellent radio with a SINGLE 15KHz roofing filter, and no provision to add more. (Except for the just-introduced 4-5KHz third party roofing filter add-on from INRAD). Both the K3 and the ProIII rely on DSP IF filtering. In my field testing to date, the K3's DSP filtering is even better than the ProIII. With the K3 DSP, you have continuously variable IF filtering in 50Hz steps from your widest roofing filter down to 50Hz. I recommend that everyone keep this filter discussion in perspective. As has been written many times, the need for additional K3 roofing filters is confined to specific needs that not everyone has. If you want to transmit FM or AM, you will need those filters since the roofing filters are also used in the transmit chain. If you know that you have problems with nearby strong signals in your operating, e.g., tough contesting environments or DX pileups as a DX station, then additional narrower roofing filters may have value. But, don't get carried away ... these are not IF filters. Back to the ProIII, of which hundreds are in use by serious contesters and major DXpeditions, a single 15KHz roofing filter and excellent DSP IF filtering provides a high performance receiver. If you are certain that you will need the ultimate in IMD performance, then consider specifically your use scenario(s). For SSB, I prefer the 2.1KHz over the 1.8KHz. The 1.8KHz SSB bandwidth is very difficult to listen with, and in those rare occasions when you might think it necessary, you can always narrow down the DSP after the 2.1KHz filter. For CW, it depends on how much you use your brain vs. the radio's filtering to focus on signals of interest. Depending entirely on the radio's filters has the disadvantage of missing the large number of stations who will call off your zero-beat frequency. The 500Hz or 400Hz filter will meet most CW needs 99% of the time, again remembering that it is only for the purpose of removing nearby large signals prior to the DSP doing the main filtering. Beyond this, additional roofing filters are the purview of fanatics or those on a DXpedition to a top Most-Needed entity or a contester seeking a new world record. Reality is not as black and white as I paint it here, of course, but this should set some guidelines on which optional filters, if any, to include in your initial K3 order. Besides, if you fill up all the K3 roofing filter slots right away, you diminish future expansion opportunity! 73, Ed - W0YK _______________________________________________ Elecraft mailing list Post to: Elecraft@mailman.qth.net 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
