RE: [Elecraft] KRX3 questions
Arie Kleingeld PA3A wrote: Lyle, I can understand why the beat effect can happen at certain frequencies. I read the message about the rounding errors. My question is: can you give an indication of how often this happens. Of course it depends on freq and filter offset but still, can you give an idication how bad it is. Anyone ? The beat is not the same as the difference in filter offsets. Somewhere in the KRX3 documentation I believe it states the beat may only be as bad as a Hz or so. 73, Bill -- View this message in context: http://n2.nabble.com/KRX3-questions-tp793412p793965.html Sent from the Elecraft mailing list archive at Nabble.com. ___ 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
RE: [Elecraft] KRX3 questions
Bill W4ZV wrote: Arie Kleingeld PA3A wrote: Lyle, I can understand why the beat effect can happen at certain frequencies. I read the message about the rounding errors. My question is: can you give an indication of how often this happens. Of course it depends on freq and filter offset but still, can you give an idication how bad it is. Anyone ? The beat is not the same as the difference in filter offsets. Somewhere in the KRX3 documentation I believe it states the beat may only be as bad as a Hz or so. 73, Bill Found the reference on page 42 of the KRX3 manual (1.6 MB): Diversity receive performance may be enhanced by using crystal filters with matched offsets (CONFIG:FLx FRQ). This ensures that the VFOs are at exactly the same frequency. Non-matched filter offsets will result in a difference of about +/- 1 Hz between the two synthesizers, which may be heard as a “beat note” under some conditions. http://www.elecraft.com/manual/KRX3_Subreceiver_Install__Operate_Rev_A_WEB.pdf 73, Bill -- View this message in context: http://n2.nabble.com/KRX3-questions-tp793412p793982.html Sent from the Elecraft mailing list archive at Nabble.com. ___ 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
Re: [Elecraft] KRX3 questions
On Sat, 30 Aug 2008 05:57:15 -0700 (PDT), Bill W4ZV [EMAIL PROTECTED] wrote: [snip] The beat is not the same as the difference in filter offsets. Somewhere in the KRX3 documentation I believe it states the beat may only be as bad as a Hz or so. 73, Bill Found the reference on page 42 of the KRX3 manual (1.6 MB): Diversity receive performance may be enhanced by using crystal filters with matched offsets (CONFIG:FLx FRQ). This ensures that the VFOs are at exactly the same frequency. Non-matched filter offsets will result in a difference of about +/- 1 Hz between the two synthesizers, which may be heard as a beat note under some conditions. http://www.elecraft.com/manual/KRX3_Subreceiver_Install__Operate_Rev_A_WEB.pdf 73, Bill This beat note experience is one of the reasons I got a K3. My Orion II always had a 6Hz difference between the A VFO and B VFO. It was very irritating after having Kenwoods and Yaesus that did not suffer from that problem. I am still waiting for my KRX3, but when I heard about the offset possibility I changed my order for the KRX3 from a 2.7 KHz filter to a 2.8Khz filter (the others ordered are all 8 pole filters) and replaced the 2.7Khz filter in the K3 with a 2.8Khz filter. Tom, N5GE - SWOT 3537 - Grid EM12jq Those who would give up Essential Liberty to purchase a little Temporary Safety deserve neither Liberty nor Safety An excerpt from a letter written in 1755 from the Assembly to the Governor of Pennsylvania. Support the entire Constitution, not just the parts you like. http://www.n5ge.com http://www.eQSL.cc/Member.cfm?N5GE ___ 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
Re: [Elecraft] KRX3 questions
Tom Childers, N5GE wrote: This beat note experience is one of the reasons I got a K3. My Orion II always had a 6Hz difference between the A VFO and B VFO. It was very irritating after having Kenwoods and Yaesus that did not suffer from that problem. I am still waiting for my KRX3, but when I heard about the offset possibility I changed my order for the KRX3 from a 2.7 KHz filter to a 2.8Khz filter (the others ordered are all 8 pole filters) and replaced the 2.7Khz filter in the K3 with a 2.8Khz filter. I experienced the same problem with my Orion but it had a constant 2.3 Hz offset. It's absolutely unnecessary to use only 8-pole filters in the K3 for diversity. In the case previously cited here by Doug N6TQS, his 2.7k offsets were only off by 10 Hz so it would not cause any problem to set both to the same offset (i.e. 10 Hz out of 2700 Hz is 0.4% and not significant). Don't be deceived in thinking 8-pole filters actually have zero Hz offsets...they don't! Several others (W0YK for one) have reported narrow CW 8-pole filters with offsets of 40-80 Hz. In a 250 Hz (actually 370 Hz) 8-pole CW filter, this can be significant (i.e. 80 Hz out of 370 Hz is ~20%). Also, if you go through the process to zero them, there is no guarantee that any two 8-pole CW filters will actually have the same offset. When I ordered my new K3 with KRX3, I did not order matched 2.7k and 500 Hz filters, thinking that the 2.7ks would not be far enough off to be significant and hoping the 500s would be about the same since they would probably come from the same manufacturing batch. The 2.7ks were off by 30 Hz so I split the difference and set both offsets to a number between, as Lyle suggested. The 500s just happened to be identical. If they had been off significantly (e.g. 50 Hz), I might have returned one and asked for a matched filter at the additional $30 cost. My KRX3 works perfectly in diversity with no beat using only 5-pole filters. 73, Bill -- View this message in context: http://n2.nabble.com/KRX3-questions-tp793412p794076.html Sent from the Elecraft mailing list archive at Nabble.com. ___ 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
Re: [Elecraft] KRX3 questions
I'm hoping that for diversity I can just switch off my main rx filters and have both with only the stock 2.7kHz filter. I only need the narrow roofing filters when I am near extremely strong local stations, which doesn't happen much. I don't see a need to have 2 sets of roofing filters unless there is very strong local QRM, perhaps 40m bc at night in some parts of Eu or on/near a contest station. David G3UNA ___ 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
Re: [Elecraft] KRX3 questions
David Cutter wrote: I'm hoping that for diversity I can just switch off my main rx filters and have both with only the stock 2.7kHz filter. I only need the narrow roofing filters when I am near extremely strong local stations, which doesn't happen much. I don't see a need to have 2 sets of roofing filters unless there is very strong local QRM, perhaps 40m bc at night in some parts of Eu or on/near a contest station. Yes you could use the K3 Utility to do that when you wanted to use diversity. I have 2.7k/1.8k/500/200 in my Main but only 2.7k/500 in the Sub. When I want to use diversity, I just remember to use a WIDTH which will auto-select either the 2.7k or 500. This way I can still use the 1.8k/200 for severe QRM situations in non-diversity and the 2.7k/500 for diversity and/or other situations. 73, Bill -- View this message in context: http://n2.nabble.com/KRX3-questions-tp793412p794168.html Sent from the Elecraft mailing list archive at Nabble.com. ___ 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
RE: [Elecraft] KRX3 questions
Bill, I have 2.7k/1.8k/500/200 in my Main but only 2.7k/500 in the Sub. When I want to use diversity, I just remember to use a WIDTH which will auto-select either the 2.7k or 500. This way I can still use the 1.8k/200 for severe QRM situations in non-diversity and the 2.7k/500 for diversity and/or other situations. With some thought would it not be possible to get 500 and 200 Hz filters with matched offsets so one could use bandwidth diversity in addition to antenna diversity? I will not be able to try that with my first K3 when that KRX3 arrives since the existing 500 and 250 Hz filters have different offsets but I will look at the 200 Hz filter in the second rig to see if it is close enough to the -790 Hz (measured in radio #1, specified for radio 2) to be useful. 73, ... Joe, W4TV -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Bill W4ZV Sent: Saturday, August 30, 2008 11:47 AM To: elecraft@mailman.qth.net Subject: Re: [Elecraft] KRX3 questions David Cutter wrote: I'm hoping that for diversity I can just switch off my main rx filters and have both with only the stock 2.7kHz filter. I only need the narrow roofing filters when I am near extremely strong local stations, which doesn't happen much. I don't see a need to have 2 sets of roofing filters unless there is very strong local QRM, perhaps 40m bc at night in some parts of Eu or on/near a contest station. Yes you could use the K3 Utility to do that when you wanted to use diversity. I have 2.7k/1.8k/500/200 in my Main but only 2.7k/500 in the Sub. When I want to use diversity, I just remember to use a WIDTH which will auto-select either the 2.7k or 500. This way I can still use the 1.8k/200 for severe QRM situations in non-diversity and the 2.7k/500 for diversity and/or other situations. 73, Bill ___ 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
RE: [Elecraft] KRX3 questions
Joe Subich, W4TV-3 wrote: Bill, I have 2.7k/1.8k/500/200 in my Main but only 2.7k/500 in the Sub. When I want to use diversity, I just remember to use a WIDTH which will auto-select either the 2.7k or 500. This way I can still use the 1.8k/200 for severe QRM situations in non-diversity and the 2.7k/500 for diversity and/or other situations. With some thought would it not be possible to get 500 and 200 Hz filters with matched offsets so one could use bandwidth diversity in addition to antenna diversity? I will not be able to try that with my first K3 when that KRX3 arrives since the existing 500 and 250 Hz filters have different offsets but I will look at the 200 Hz filter in the second rig to see if it is close enough to the -790 Hz (measured in radio #1, specified for radio 2) to be useful. Sure you could probably do that if the offsets between the 500 and 200 are not too far off. You'll probably want to set the 500 equal to the 200 rather than vice versa if they aren't identical (i.e. a shift in a 500 Hz BW is not as critical as the same shift in a 200). I'm not at home now but I recall my 500s are both -0.84 and my 200 is -0.91. If I wanted to try what you described I would set both 500s to -0.91 since a shift of 70 Hz is still not unreasonable in ~500 Hz total BW. The magicians at Elecraft are now at work on an improved DUAL PB which will allow more flexibility in the context WIDTH setting, which would accomplish somewhat similar results (but the context BW is attenuated by -24 dB versus the focus BW). 73, Bill -- View this message in context: http://n2.nabble.com/KRX3-questions-tp793412p794215.html Sent from the Elecraft mailing list archive at Nabble.com. ___ 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
RE: [Elecraft] KRX3 questions
The magicians at Elecraft are now at work on an improved DUAL PB which will allow more flexibility in the context WIDTH setting, which would accomplish somewhat similar results (but the context BW is attenuated by -24 dB versus the focus BW). I've tried the updated context filter in beta 2.34. The problem for me is that the context area is attenuated more than I would like and the peak (50 Hz?) is a bit narrow. I would like to try the transmit antenna on the subreceiver with a relatively wide filter (600 - 1000 Hz) to get an idea of the overall activity and a low noise (Beverage, K9AY, phased array, etc.) receive antenna on the main antenna with a narrow (e.g. 200Hz) filter to focus on the desired signal. 73, ... Joe, W4TV -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Bill W4ZV Sent: Saturday, August 30, 2008 12:21 PM To: elecraft@mailman.qth.net Subject: RE: [Elecraft] KRX3 questions Joe Subich, W4TV-3 wrote: Bill, I have 2.7k/1.8k/500/200 in my Main but only 2.7k/500 in the Sub. When I want to use diversity, I just remember to use a WIDTH which will auto-select either the 2.7k or 500. This way I can still use the 1.8k/200 for severe QRM situations in non-diversity and the 2.7k/500 for diversity and/or other situations. With some thought would it not be possible to get 500 and 200 Hz filters with matched offsets so one could use bandwidth diversity in addition to antenna diversity? I will not be able to try that with my first K3 when that KRX3 arrives since the existing 500 and 250 Hz filters have different offsets but I will look at the 200 Hz filter in the second rig to see if it is close enough to the -790 Hz (measured in radio #1, specified for radio 2) to be useful. Sure you could probably do that if the offsets between the 500 and 200 are not too far off. You'll probably want to set the 500 equal to the 200 rather than vice versa if they aren't identical (i.e. a shift in a 500 Hz BW is not as critical as the same shift in a 200). I'm not at home now but I recall my 500s are both -0.84 and my 200 is -0.91. If I wanted to try what you described I would set both 500s to -0.91 since a shift of 70 Hz is still not unreasonable in ~500 Hz total BW. The magicians at Elecraft are now at work on an improved DUAL PB which will allow more flexibility in the context WIDTH setting, which would accomplish somewhat similar results (but the context BW is attenuated by -24 dB versus the focus BW). 73, Bill ___ 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
RE: [Elecraft] KRX3 questions
For me the context area isn't attenuated at all. I believe its 200Hz wide in the middle... The only difference I thought was that it can now go down to as narrow as 400 on the outer skirts rather than the 600 that it used to be limited to. Doesn't seem to make too much difference to me but I do admit that I like not being limited as I did run it at 600 at times and wished I wasn't being stopped. I find that for me it may be a dumb idea to do something but I usually don't like not being allowed to. Thats one of the reasons why my 250Hz filter is fully allowed to be used in SSB on my K3. Not that I'd want to do that but why limit myself. ~Brett (KC7OTG) On Sat, 2008-08-30 at 18:50 -0400, Joe Subich, W4TV wrote: The magicians at Elecraft are now at work on an improved DUAL PB which will allow more flexibility in the context WIDTH setting, which would accomplish somewhat similar results (but the context BW is attenuated by -24 dB versus the focus BW). I've tried the updated context filter in beta 2.34. The problem for me is that the context area is attenuated more than I would like and the peak (50 Hz?) is a bit narrow. I would like to try the transmit antenna on the subreceiver with a relatively wide filter (600 - 1000 Hz) to get an idea of the overall activity and a low noise (Beverage, K9AY, phased array, etc.) receive antenna on the main antenna with a narrow (e.g. 200Hz) filter to focus on the desired signal. 73, ... Joe, W4TV -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Bill W4ZV Sent: Saturday, August 30, 2008 12:21 PM To: elecraft@mailman.qth.net Subject: RE: [Elecraft] KRX3 questions Joe Subich, W4TV-3 wrote: Bill, I have 2.7k/1.8k/500/200 in my Main but only 2.7k/500 in the Sub. When I want to use diversity, I just remember to use a WIDTH which will auto-select either the 2.7k or 500. This way I can still use the 1.8k/200 for severe QRM situations in non-diversity and the 2.7k/500 for diversity and/or other situations. With some thought would it not be possible to get 500 and 200 Hz filters with matched offsets so one could use bandwidth diversity in addition to antenna diversity? I will not be able to try that with my first K3 when that KRX3 arrives since the existing 500 and 250 Hz filters have different offsets but I will look at the 200 Hz filter in the second rig to see if it is close enough to the -790 Hz (measured in radio #1, specified for radio 2) to be useful. Sure you could probably do that if the offsets between the 500 and 200 are not too far off. You'll probably want to set the 500 equal to the 200 rather than vice versa if they aren't identical (i.e. a shift in a 500 Hz BW is not as critical as the same shift in a 200). I'm not at home now but I recall my 500s are both -0.84 and my 200 is -0.91. If I wanted to try what you described I would set both 500s to -0.91 since a shift of 70 Hz is still not unreasonable in ~500 Hz total BW. The magicians at Elecraft are now at work on an improved DUAL PB which will allow more flexibility in the context WIDTH setting, which would accomplish somewhat similar results (but the context BW is attenuated by -24 dB versus the focus BW). 73, Bill ___ 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 ___ 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
Re: [Elecraft] KRX3 questions
I've finally put the second RX in my K3 #22. I have 2.7k filters with -0.86 and -0.87 offsets- have I ended up with filters that are matched enough for diversity reception? Yes, but set them both to the same value. A 10 Hz error is not going matter to the 2.7 kHz filter's passband response, but the 10 Hz difference in offset may result in an annoying beat effect when both receivers are tuned to the same indicated frequency. 73, Lyle KK7P ___ 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
RE: [Elecraft] KRX3 questions
Lyle, I can understand why the beat effect can happen at certain frequencies. I read the message about the rounding errors. My question is: can you give an indication of how often this happens. Of course it depends on freq and filter offset but still, can you give an idication how bad it is. Anyone ? Thanks. Arie PA3A - I've finally put the second RX in my K3 #22. I have 2.7k filters with -0.86 and -0.87 offsets- have I ended up with filters that are matched enough for diversity reception? Yes, but set them both to the same value. A 10 Hz error is not going matter to the 2.7 kHz filter's passband response, but the 10 Hz difference in offset may result in an annoying beat effect when both receivers are tuned to the same indicated frequency. 73, Lyle KK7P __ ___ 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
