Maybe I'll put the feature in and let you be my guinea pig, Joe. One complaint about noise bandwidth and it comes back out ;)
Wayne On Sep 21, 2012, at 4:20 PM, Joe Subich, W4TV wrote: > >> This in-band noise "pedestal" could be 20-30 dB above the normal >> transmit noise floor if you were using a lot of mic gain and/or >> compression. If you were using high power in these modes, your signal >> would now be much more likely to bring up the receive noise floor at >> nearby stations. > > It would seem that the same argument would be made against using the > 2.7 or 2.8 KHz filters for CW or digital modes that have a transmit > bandwidth of 50 to 100 Hz. Why generate an excessively wide 3 KHz > noise > pedestal for CW or PSK31/63 or even FSK RTTY (300 Hz required)? > > This is all academic since it is easy - although very inconvenient - > to > set FL1 BW to 6.00 with the FM filter to enable AM/ESSB and return it > to 13.00 to go back to FM. > > The real issue is that any user with three "narrow" filters for SSB > and > CW/Digital is precluded from using both FM and AM/ESSB without playing > games with FL1 BW. > > 73, > > ... Joe, W4TV > > > On 9/21/2012 6:40 PM, Wayne Burdick wrote: >> The 6 kHz filter band-limits the transmit noise originating from the >> DAC and the transmit mixer to a bandwidth appropriate for AM and ESSB >> modes. The 15 kHz filter would allow a noise bandwidth over twice as >> wide. >> >> This in-band noise "pedestal" could be 20-30 dB above the normal >> transmit noise floor if you were using a lot of mic gain and/or >> compression. If you were using high power in these modes, your signal >> would now be much more likely to bring up the receive noise floor at >> nearby stations. >> >> Do you really want to create a 15-kHz wide swath of broadband noise >> when using ESSB or AM? >> >> I don't. That's why I haven't modified the code to allow use of the >> FM >> filter for this purpose. I suppose it could be YAMU (yet another menu >> entry), forcing you to do at least a minimum amount of soul-searching >> before "going broadband" :) >> >> 73, >> Wayne >> N6KR >> >> >> On Sep 21, 2012, at 3:09 PM, Thomas Horsten wrote: >> >>> Hi Gary, >>> >>> The point is not to widen the SSB but to use the FM crystal filter >>> to limit >>> it. The DSP does the actual shaping of the TX signal which will >>> still be >>> the same width regardless of whether you're using the 6kHz filter or >>> the >>> 12.5kHz FM one. >>> >>> The idea is to be able to use the FM filter for AM and ESSB as well >>> instead >>> of filling up two precious filter slots, when what you may want/need >>> are >>> closer filters on the low end (say, 400 and 200 Hz). >>> >>> 73, Thomas M0TRN >>> >>> On 21 September 2012 22:00, Gary Gregory <[email protected]> >>> wrote: >>> >>>> Joe, >>>> >>>> I have to ask, why? >>>> >>>> In VK we have a 3Khz SSB BW written into our LCD's and yet some >>>> folks >>>> consume 10Khz out here on a net which tears up a considerable >>>> amount of >>>> spectrum. >>>> >>>> What advantage do you see to widen the ESSB? >>>> >>>> Not sure I follow your thoughts here, hence the question Joe. >>>> >>>> 73 >>>> >>> ______________________________________________________________ >>> 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 >> >> ______________________________________________________________ >> 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 >> > ______________________________________________________________ > 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 ______________________________________________________________ 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
