Re: [Elecraft] K3 sub rx matched filters
The 8 pole filters have no offset. So if you have already an 8 pole filter you just need to buy one. 73 Henk W6/PA5KT Quoting jeff kb2m : > I'm thinking of upgrading my K3 by adding a KRX3 sub receiver. One of the > things I want to try in the near future is diversity reception. Now, I think > I need a matched pair of filters to operate in diversity mode? Or does this > just pertain to the 5 pole filters? Or, if I already have an 8 pole 1.8 > filter would I just have to buy another one ? I tried to search the archives > and there appears to be no keyword search? Thanks in advance for any help > with this > > 73 Jeff kb2m > > __ > 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 > > __ 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
Re: [Elecraft] K3 sub rx matched filters
Don Wilhelm wrote: > Supposedly, the 8 pole filters do not have to be matched (they do not > have offset numbers associated with them), but in practice, they may > have a small offset and some ''tweaking" of the offset values may be > required to eliminate the "wush, wush" sound when using diversity. For what it's worth, I have only a 2.8 kHz filter in my KRX3, and 2.8, 1.0 and 0.4 kHz filters in my main receiver. Offsets are 0. I use diversity a lot and haven't had any problems. Normally I have the bandwidth adjusted to 400 Hz or less when trying to work weak CW signals. I often find that intelligibility is improved with diversity (on 40 meters I use a dipole as the main antenna and a vertical as the second rx antenna). It's hard to describe, but the signal seems to stand out better. It might be due to the reduction in QSB gained by polarization diversity, or something else, having to do with noise. I'm not sure. On 160 I use a 200' wire thrown on the ground as the second rx antenna (main is a vertical). There is some improvement, but nothing like 40. On 20, I have a 4-el tribander at 40'. It is *always* better than the vertical by many dB, so I don't bother with diversity. -- 73, Vic, K2VCO Fresno CA http://www.qsl.net/k2vco __ 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
Re: [Elecraft] K3 sub rx matched filters
About this "wush, wush" soundDoes this wushing occur as you tune across stations when in diversity mode or does it just set there and constantly wush wush? Can't you adjust the compensation for these filters in the menu? I don't understand why this happens. I had an IC-7800 and played with diversity recption. Of course there were no physical filter options but there was no wushing sounds either. Steve Ellington n...@carolina.rr.com - Original Message - From: "Don Wilhelm" To: "jeff kb2m" Cc: Sent: Friday, March 27, 2009 10:23 AM Subject: Re: [Elecraft] K3 sub rx matched filters > Jeff, > > The filter offsets should be set the same for diversity reception, and > for that to happen most easily, the filters can be matched. You may > notice a "wush, wush" sound if the offsets are different. > But being practical, the *difference* between the actual offsets of the > filters will be within tens of Hz, and for a wide filter (1.8 kHz or 2.7 > kHz), setting the K3 offset values to the average of the two filters > will work fine. OTOH, with narrow filters such as those used for CW, > the two offsets must be closely matched because the difference in the > offsets is a larger percentage of the filter width, and requires matched > filters. It is the difference between the offsets that matters, not the > actual offset value. > > Supposedly, the 8 pole filters do not have to be matched (they do not > have offset numbers associated with them), but in practice, they may > have a small offset and some ''tweaking" of the offset values may be > required to eliminate the "wush, wush" sound when using diversity. > > 73, > Don W3FPR > > jeff kb2m wrote: >> I'm thinking of upgrading my K3 by adding a KRX3 sub receiver. One of >> the >> things I want to try in the near future is diversity reception. Now, I >> think >> I need a matched pair of filters to operate in diversity mode? Or does >> this >> just pertain to the 5 pole filters? Or, if I already have an 8 pole 1.8 >> filter would I just have to buy another one ? I tried to search the >> archives >> and there appears to be no keyword search? Thanks in advance for any help >> with this >> >> 73 Jeff kb2m >> >> > __ > 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 No virus found in this incoming message. Checked by AVG - www.avg.com Version: 8.0.238 / Virus Database: 270.11.30/2026 - Release Date: 03/27/09 07:13:00 __ 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
Re: [Elecraft] K3 sub rx matched filters
Jeff, The filter offsets should be set the same for diversity reception, and for that to happen most easily, the filters can be matched. You may notice a "wush, wush" sound if the offsets are different. But being practical, the *difference* between the actual offsets of the filters will be within tens of Hz, and for a wide filter (1.8 kHz or 2.7 kHz), setting the K3 offset values to the average of the two filters will work fine. OTOH, with narrow filters such as those used for CW, the two offsets must be closely matched because the difference in the offsets is a larger percentage of the filter width, and requires matched filters. It is the difference between the offsets that matters, not the actual offset value. Supposedly, the 8 pole filters do not have to be matched (they do not have offset numbers associated with them), but in practice, they may have a small offset and some ''tweaking" of the offset values may be required to eliminate the "wush, wush" sound when using diversity. 73, Don W3FPR jeff kb2m wrote: > I'm thinking of upgrading my K3 by adding a KRX3 sub receiver. One of the > things I want to try in the near future is diversity reception. Now, I think > I need a matched pair of filters to operate in diversity mode? Or does this > just pertain to the 5 pole filters? Or, if I already have an 8 pole 1.8 > filter would I just have to buy another one ? I tried to search the archives > and there appears to be no keyword search? Thanks in advance for any help > with this > > 73 Jeff kb2m > > __ 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
Re: [Elecraft] K3 sub rx matched filters
These are good questions and what kind of problems occur when these filters are not matched? Steve Ellington n...@carolina.rr.com - Original Message - From: "jeff kb2m" To: Sent: Friday, March 27, 2009 9:41 AM Subject: [Elecraft] K3 sub rx matched filters > I'm thinking of upgrading my K3 by adding a KRX3 sub receiver. One of the > things I want to try in the near future is diversity reception. Now, I > think > I need a matched pair of filters to operate in diversity mode? Or does > this > just pertain to the 5 pole filters? Or, if I already have an 8 pole 1.8 > filter would I just have to buy another one ? I tried to search the > archives > and there appears to be no keyword search? Thanks in advance for any help > with this > > 73 Jeff kb2m > > __ > 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 No virus found in this incoming message. Checked by AVG - www.avg.com Version: 8.0.238 / Virus Database: 270.11.30/2026 - Release Date: 03/27/09 07:13:00 __ 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
