Yet another filter question
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Hi all
I apologize if this topic has been covered here before. I've had my K3 for about a year now, and I'm considering adding another roofing filter. I currently have the 400 hz 8 pole filter and it has served me very well, but there were several instances during the 2014 WPX cw contest as well as 2014 SS where I needed something tighter. I've seen the filter plots for the 5 pole and 8 pole filters, and while my initial gut feeling was to go with the 8 pole 250 hz filter, I'm now questioning whether or not that would be wise. According to the plots, there isn't much difference between the two filters, and based on this data alone it would seem that the better choice would be to go with the 200hz 5-pole. I'm sure I'm missing something here. Thoughts? Thanks 73, Morgan, NS0R. ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] |
Re: Yet another filter question
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> there isn't much difference between the two [400 Hz and 250 Hz] > filters, Correct. There is much debate but in my opinion the difference is not worth the cost of both filters. > based on this data alone it would seem that the better choice would > be to go with the 200hz 5-pole. Even though the 200 Hz filter has a broader shape factor, comparing selectivity curves of the 200 and 250 Hz filters shows that the 200 Hz filter is tighter than the 250 Hz filter until the skirt response is down nearly 50 dB. My decision was to pair the 200 Hz with the 400 Hz filter. 73, ... Joe, W4TV On 2015-05-15 12:33 PM, Morgan Bailey, II wrote: > Hi all > > I apologize if this topic has been covered here before. > > I've had my K3 for about a year now, and I'm considering adding another > roofing filter. I currently have the 400 hz 8 pole filter and it has > served me very well, but there were several instances during the 2014 WPX > cw contest as well as 2014 SS where I needed something tighter. I've seen > the filter plots for the 5 pole and 8 pole filters, and while my initial > gut feeling was to go with the 8 pole 250 hz filter, I'm now questioning > whether or not that would be wise. According to the plots, there isn't > much difference between the two filters, and based on this data alone it > would seem that the better choice would be to go with the 200hz 5-pole. > > I'm sure I'm missing something here. > > Thoughts? > > Thanks > > 73, Morgan, NS0R. > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:[hidden email] > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > Message delivered to [hidden email] > Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] |
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In reply to this post by NS0R
Why are you considering a tighter roofing filter?
Jim W6AIM -----Original Message----- From: Elecraft [mailto:[hidden email]] On Behalf Of Morgan Bailey, II Sent: Friday, May 15, 2015 9:33 AM To: Elecraft Reflector Subject: [Elecraft] Yet another filter question Hi all I apologize if this topic has been covered here before. I've had my K3 for about a year now, and I'm considering adding another roofing filter. I currently have the 400 hz 8 pole filter and it has served me very well, but there were several instances during the 2014 WPX cw contest as well as 2014 SS where I needed something tighter. I've seen the filter plots for the 5 pole and 8 pole filters, and while my initial gut feeling was to go with the 8 pole 250 hz filter, I'm now questioning whether or not that would be wise. According to the plots, there isn't much difference between the two filters, and based on this data alone it would seem that the better choice would be to go with the 200hz 5-pole. I'm sure I'm missing something here. Thoughts? Thanks 73, Morgan, NS0R. ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] |
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In reply to this post by NS0R
Sri, just read why.
CWSS is an interesting contest with the K3. I have both 400 and 200 and rarely went to the 200 Hz. Not worth it. Jim W6AIM -----Original Message----- From: Elecraft [mailto:[hidden email]] On Behalf Of Morgan Bailey, II Sent: Friday, May 15, 2015 9:33 AM To: Elecraft Reflector Subject: [Elecraft] Yet another filter question Hi all I apologize if this topic has been covered here before. I've had my K3 for about a year now, and I'm considering adding another roofing filter. I currently have the 400 hz 8 pole filter and it has served me very well, but there were several instances during the 2014 WPX cw contest as well as 2014 SS where I needed something tighter. I've seen the filter plots for the 5 pole and 8 pole filters, and while my initial gut feeling was to go with the 8 pole 250 hz filter, I'm now questioning whether or not that would be wise. According to the plots, there isn't much difference between the two filters, and based on this data alone it would seem that the better choice would be to go with the 200hz 5-pole. I'm sure I'm missing something here. Thoughts? Thanks 73, Morgan, NS0R. ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] |
Re: Yet another filter question
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In reply to this post by NS0R
You aren't missing anything. The 6 dB bandwidth of the "400" Hz filter is closer to 450 Hz and the "250" is closer to 350. The "200" is close to 250. I took the advice of the K3's designer and chose the 200 to go with my 400. I've been happy with the combination.
Vic 4X6GP/K2VCO > On May 15, 2015, at 7:33 PM, Morgan Bailey, II <[hidden email]> wrote: > > Hi all > > I apologize if this topic has been covered here before. > > I've had my K3 for about a year now, and I'm considering adding another > roofing filter. I currently have the 400 hz 8 pole filter and it has > served me very well, but there were several instances during the 2014 WPX > cw contest as well as 2014 SS where I needed something tighter. I've seen > the filter plots for the 5 pole and 8 pole filters, and while my initial > gut feeling was to go with the 8 pole 250 hz filter, I'm now questioning > whether or not that would be wise. According to the plots, there isn't > much difference between the two filters, and based on this data alone it > would seem that the better choice would be to go with the 200hz 5-pole. > > I'm sure I'm missing something here. > > Thoughts? > > Thanks > > 73, Morgan, NS0R. > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:[hidden email] > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > Message delivered to [hidden email] Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] |
Re: Yet another filter question
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In reply to this post by Jim Bolit
Certainly seems to me that he pretty well covered that in is post....
73, Ross N4RP On 5/15/2015 2:54 PM, jim wrote: > Why are you considering a tighter roofing filter? > > Jim > W6AIM > > -----Original Message----- > From: Elecraft [mailto:[hidden email]] On Behalf Of Morgan > Bailey, II > Sent: Friday, May 15, 2015 9:33 AM > To: Elecraft Reflector > Subject: [Elecraft] Yet another filter question > > Hi all > > I apologize if this topic has been covered here before. > > I've had my K3 for about a year now, and I'm considering adding another > roofing filter. I currently have the 400 hz 8 pole filter and it has served > me very well, but there were several instances during the 2014 WPX cw > contest as well as 2014 SS where I needed something tighter. I've seen the > filter plots for the 5 pole and 8 pole filters, and while my initial gut > feeling was to go with the 8 pole 250 hz filter, I'm now questioning whether > or not that would be wise. According to the plots, there isn't much > difference between the two filters, and based on this data alone it would > seem that the better choice would be to go with the 200hz 5-pole. > > I'm sure I'm missing something here. > > Thoughts? > > Thanks > > 73, Morgan, NS0R. > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:[hidden email] > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html Message > delivered to [hidden email] > > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:[hidden email] > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > Message delivered to [hidden email] -- FCC Section 97.313(a) “At all times, an amateur station must use the minimum transmitter power necessary to carry out the desired communications.” ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] |
Re: Yet another filter question
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In reply to this post by NS0R
Morgan,
I have the K3 RX and SUB RX too and have both the 200 and 400 Hz filters in each. My location is a bit noisy so I often find myself going down to 200 Hz filters......makes a difference here. I also like to hit A>B and listen at 200 in my left ear plus 200 Hz in my right ear on the same frequency.........also use diversity on occastion..........helps bring up the signal out of the noise. Phil, W0XI > Morgan Bailey, II <mailto:[hidden email]> > Friday, May 15, 2015 11:33 AM > Hi all > > I apologize if this topic has been covered here before. > > I've had my K3 for about a year now, and I'm considering adding another > roofing filter. I currently have the 400 hz 8 pole filter and it has > served me very well, but there were several instances during the 2014 WPX > cw contest as well as 2014 SS where I needed something tighter. I've seen > the filter plots for the 5 pole and 8 pole filters, and while my initial > gut feeling was to go with the 8 pole 250 hz filter, I'm now questioning > whether or not that would be wise. According to the plots, there isn't > much difference between the two filters, and based on this data alone it > would seem that the better choice would be to go with the 200hz 5-pole. > > I'm sure I'm missing something here. > > Thoughts? > > Thanks > > 73, Morgan, NS0R. > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:[hidden email] > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > Message delivered to [hidden email] > --- This email has been checked for viruses by Avast antivirus software. http://www.avast.com ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] |
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In reply to this post by NS0R
Dear Morgan,
I remember something about 5 pole filters have to be paired (or what the exact word was) whereas 8 pole filters can be mixed without any further considerations. 73, Kjeld, OZ1CCM -----Original Message----- From: Elecraft [mailto:[hidden email]] On Behalf Of Morgan Bailey, II Sent: 15. maj 2015 18:33 To: Elecraft Reflector Subject: [Elecraft] Yet another filter question Hi all I apologize if this topic has been covered here before. I've had my K3 for about a year now, and I'm considering adding another roofing filter. I currently have the 400 hz 8 pole filter and it has served me very well, but there were several instances during the 2014 WPX cw contest as well as 2014 SS where I needed something tighter. I've seen the filter plots for the 5 pole and 8 pole filters, and while my initial gut feeling was to go with the 8 pole 250 hz filter, I'm now questioning whether or not that would be wise. According to the plots, there isn't much difference between the two filters, and based on this data alone it would seem that the better choice would be to go with the 200hz 5-pole. I'm sure I'm missing something here. Thoughts? Thanks 73, Morgan, NS0R. ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] |
Re: Yet another filter question
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The 5 pole filters all have a slight frequency offset which varies from filter to filter. *When used for diversity* the filter offsets need to be matched (within 10 Hz) so a single synthesizer can drive both receivers to maintain phase lock. The issue is not critical with the 2.7 KHz filter as modest offsets can be accommodated by setting both for the average. However with the narrow filters a 50 Hz difference in the filter center frequencies can represent a substantial percentage of the filter passband <G>. Fortunately, the issue can be addressed by purchasing both filters at the same time and specifying "frequency matching." 73, ... Joe, W4TV On 2015-05-17 11:21 AM, Kjeld Holm wrote: > Dear Morgan, > I remember something about 5 pole filters have to be paired (or what the > exact word was) whereas 8 pole filters can be mixed without any further > considerations. > 73, Kjeld, OZ1CCM > > > -----Original Message----- > From: Elecraft [mailto:[hidden email]] On Behalf Of Morgan > Bailey, II > Sent: 15. maj 2015 18:33 > To: Elecraft Reflector > Subject: [Elecraft] Yet another filter question > > Hi all > > I apologize if this topic has been covered here before. > > I've had my K3 for about a year now, and I'm considering adding another > roofing filter. I currently have the 400 hz 8 pole filter and it has served > me very well, but there were several instances during the 2014 WPX cw > contest as well as 2014 SS where I needed something tighter. I've seen the > filter plots for the 5 pole and 8 pole filters, and while my initial gut > feeling was to go with the 8 pole 250 hz filter, I'm now questioning whether > or not that would be wise. According to the plots, there isn't much > difference between the two filters, and based on this data alone it would > seem that the better choice would be to go with the 200hz 5-pole. > > I'm sure I'm missing something here. > > Thoughts? > > Thanks > > 73, Morgan, NS0R. > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:[hidden email] > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html Message > delivered to [hidden email] > > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:[hidden email] > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > Message delivered to [hidden email] > Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] |
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