Hi Bruce,
No, the 13KHz filter will be used for AM SW/MW/LW reception, not FM on the sub. The other FM filter on the main will only be used for 10m FM TX/RX. Here's an excerpt from a conversation I had with another fellow regarding the use of FM filters for AM broadcast reception: > Just to make sure I understand you, the AM filter is only required if > one desires to transmit in AM or use ESSB. > Otherwise, AM reception like SW can still be piped through the 13KHz > FM filter? Correct, I use the FM filter for listening to AM broadcast or SWL on a fairly regular basis. > How does the audio of AM SW sound going through the FM filter? > Bandwidth is obviously wider, so I'm assuming higher fidelity? Somewhat higher fidelity. The K3's DSP has a fairly sharp cutoff at 4200 Hz so you will never get more than that but the FM filter allows the full 4.5 KHz where the AM filter starts to roll off at 3 KHz but still has some audio response down the filter skirts. I hope that someday Elecraft will "open up" the audio in AM so we can hear 5.5 or 6 KHz which as good as it gets these days. Hope that helps to clarify. 73, James KC2UEE _____ From: Bruce McLaughlin [mailto:bmcla...@bex.net] Sent: Wednesday, February 11, 2009 8:27 PM To: 'James Sarte' Subject: RE: [Elecraft] K3 configuration finalization plus diversity receive antenna question That sounds like a well-rounded package, although, I'm a bit confused by your plan to use the FM filter on the sub receiver for broadcast reception. The K-3 will not go to the FM broadcast band and I don't think you can get there using a transverter either. Also, the 13 kHz roofing filter, and the DSP are not really wide enough for broadcast FM. The 15 kHz deviation is such that I think you will have considerable distortion on a system designed for a maximum of 5 kHz deviation if it is recognizable at all. I could be mistaken about that, but you may want to check with others. I also wonder if you could save a bit of money by having only one 13 kHz filter installed on the main receiver. Assuming it will work for FM broadcast reception, unless you plan to listen to FM broadcasts for long periods of time, I would think using the main receiver for that purpose would probably be sufficient. It also could be used for FM transmission on the ham bands. As I am sure you know, you cannot transmit using the sub receiver. I have 2 K3s. The older unit has an FM filter installed in the main receiver. The newest unit has no FM receiver filter since my use of FM is likely to be very limited and certainly not at all until 10 meters begins to work again. But your plans may be different and you may have different needs. Bruce-W8FU
______________________________________________________________ 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
