Re: [Elecraft] [K3] Elecraft roofing filters
I would say that you don't really need all those filters. The DSP filter does all the heavy lifting except for removing the artifacts from signals that are inside the pass band of the roofing filter. I have the 2.7k, 500 Hz and 250 Hz in my main receiver and just the 2.7K and 500 Hz in my second receiver. I don't feel the need for more, but I have zero interest in FM, AM and ESSB. Willis 'Cookie' Cooke K5EWJ --- On Fri, 2/6/09, Kjeld Holm k...@kh-translation.dk wrote: From: Kjeld Holm k...@kh-translation.dk Subject: Re: [Elecraft] [K3] Elecraft roofing filters To: elecraft@mailman.qth.net Date: Friday, February 6, 2009, 12:31 AM Dear all, Once and again: Thanks to all for very interesting and informative answers. Right now my conclusion according to my planed way of operation is the following setup 2 pcs KFL3A-2.8_2.7sw replacement K3 and KRX3 2 pcs KFL3A-1.8K SSB 2 pcs KFL3A-200 5-pole CW + matching 2 pcs KFL3A-400 CW 2 pcs KFL3B-FM FM For the purpose of working as many DXCC countries as possible including picking new ones during contests on crowded bands. As I understand this configuration will not allow me to receive or transmit on AM but it will maybe allow ESSB later if the firmware can be modified to use the FM filter for ESSB. Any further comments before my ordering will be appreciated. Vy 73 OZ1CCM Kjeld -Original Message- From: elecraft-boun...@mailman.qth.net [mailto:elecraft-boun...@mailman.qth.net] On Behalf Of Kjeld Holm Sent: 5. februar 2009 17:27 To: elecraft@mailman.qth.net Subject: Re: [Elecraft] [K3] Elecraft roofing filters Dear all, Thanks for all the kind answers. Sorry for all that fuss. Somehow I mixed up everything so I ended up thinking of some nonsense like 1.0 kHz for SSB. :-o I will go for 250 Hz and 400 Hz for CW plus 2.8 kHz for SSB. And also filters for AM and FM. Vy 73 OZ1CCM Kjeld -Original Message- From: W0MU Mike Fatchett [mailto:w...@w0mu.com] Sent: 5. februar 2009 15:28 To: 'Kjeld Holm' Subject: RE: [Elecraft] [K3] Elecraft roofing filters They are available on the website. KFL3A-1.0K 1 kHz, 8-pole roofing filter 125.95 I have one in my K3 but I don't use it too much. You might want to use it over a 250 or 500 filter to listen to a pile up so you can hear if the station is working people above or below his frequency. I have listened to SSB a bit on the filter and while very narrow for SSB you can hear the station. The better question might be, what modes do you like to operate? I am about to order a second K3 and I was going to go with the following filters. 2.8 replacing the stock 2.7/ AM/ FM/ 400 or 500 and 250. If you never play to transmit on AM or want to do ESSB or FM those slots would be available. The K3 I have now has the 2.7 which is being replaced with the 2.8/1.8/1.0/400/200 in the main rcv, 2.8/400 in the sub. Mike W0MU A slip of the foot you may soon recover, but a slip of the tongue you may never get over. Ben Franklin -Original Message- From: elecraft-boun...@mailman.qth.net [mailto:elecraft-boun...@mailman.qth.net] On Behalf Of Kjeld Holm Sent: Thursday, February 05, 2009 5:44 AM To: 'ElecraftList' Subject: [Elecraft] [K3] Elecraft roofing filters Dear all, In the Roofing Filter Notes from Wayne and Eric link on the Order page I see the two sentences: Add narrower/wider filters as you prefer. I like to use the 1.0 kHz crystal filter when tuning a crowded band or listening to a pile up. Can anyone point me to a place that can tell me what the 1.0 kHz crystal filter is, where to obtain one and when it is worth using? Vy 73 OZ1CCM Kjeld __ 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 __ 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] Elecraft roofing filters
Dear all, Once and again: Thanks to all for very interesting and informative answers. Right now my conclusion according to my planed way of operation is the following setup 2 pcs KFL3A-2.8_2.7sw replacement K3 and KRX3 2 pcs KFL3A-1.8K SSB 2 pcs KFL3A-200 5-pole CW + matching 2 pcs KFL3A-400 CW 2 pcs KFL3B-FM FM For the purpose of working as many DXCC countries as possible including picking new ones during contests on crowded bands. As I understand this configuration will not allow me to receive or transmit on AM but it will maybe allow ESSB later if the firmware can be modified to use the FM filter for ESSB. Any further comments before my ordering will be appreciated. Vy 73 OZ1CCM Kjeld -Original Message- From: elecraft-boun...@mailman.qth.net [mailto:elecraft-boun...@mailman.qth.net] On Behalf Of Kjeld Holm Sent: 5. februar 2009 17:27 To: elecraft@mailman.qth.net Subject: Re: [Elecraft] [K3] Elecraft roofing filters Dear all, Thanks for all the kind answers. Sorry for all that fuss. Somehow I mixed up everything so I ended up thinking of some nonsense like 1.0 kHz for SSB. :-o I will go for 250 Hz and 400 Hz for CW plus 2.8 kHz for SSB. And also filters for AM and FM. Vy 73 OZ1CCM Kjeld -Original Message- From: W0MU Mike Fatchett [mailto:w...@w0mu.com] Sent: 5. februar 2009 15:28 To: 'Kjeld Holm' Subject: RE: [Elecraft] [K3] Elecraft roofing filters They are available on the website. KFL3A-1.0K 1 kHz, 8-pole roofing filter125.95 I have one in my K3 but I don't use it too much. You might want to use it over a 250 or 500 filter to listen to a pile up so you can hear if the station is working people above or below his frequency. I have listened to SSB a bit on the filter and while very narrow for SSB you can hear the station. The better question might be, what modes do you like to operate? I am about to order a second K3 and I was going to go with the following filters. 2.8 replacing the stock 2.7/ AM/ FM/ 400 or 500 and 250. If you never play to transmit on AM or want to do ESSB or FM those slots would be available. The K3 I have now has the 2.7 which is being replaced with the 2.8/1.8/1.0/400/200 in the main rcv, 2.8/400 in the sub. Mike W0MU A slip of the foot you may soon recover, but a slip of the tongue you may never get over. Ben Franklin -Original Message- From: elecraft-boun...@mailman.qth.net [mailto:elecraft-boun...@mailman.qth.net] On Behalf Of Kjeld Holm Sent: Thursday, February 05, 2009 5:44 AM To: 'ElecraftList' Subject: [Elecraft] [K3] Elecraft roofing filters Dear all, In the Roofing Filter Notes from Wayne and Eric link on the Order page I see the two sentences: Add narrower/wider filters as you prefer. I like to use the 1.0 kHz crystal filter when tuning a crowded band or listening to a pile up. Can anyone point me to a place that can tell me what the 1.0 kHz crystal filter is, where to obtain one and when it is worth using? Vy 73 OZ1CCM Kjeld __ 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] Elecraft roofing filters
This filter mystery seems to be a common exercise for purchasers of a K3. Having just gone through this myself, reading all of the data available, and consulting with K3 owners for their experiences, I settled on the following assortment of filters for my new K3: KFL3A-6K 6.0 kHz 8 pole KFL3A-2.7K 2.7 kHz 5 pole (standard) KFL3A-500500 Hz 5 pole KFL3A-200200 Hz 5 pole I am extremely pleased with the performance with these filters and along with the DSP, even the bedlam that was going on in the recent CQWW 160 contest was easy to listen to and to sort out weak signals among the very strong. I cannot say enough about how pleased I am with the performance. My only wish is that I could be heard as well as I now hear! If I was to add anything, it might be the 1 kHz filter to fill in the wide gap between the 2.7k and 500 Hz filters but this is a personal suspicion rather than a scientific determination. 73, Bob W5OV -Original Message- From: elecraft-boun...@mailman.qth.net [mailto:elecraft-boun...@mailman.qth.net] On Behalf Of Kjeld Holm Sent: Friday, February 06, 2009 2:32 AM To: elecraft@mailman.qth.net Subject: Re: [Elecraft] [K3] Elecraft roofing filters Dear all, Once and again: Thanks to all for very interesting and informative answers. Right now my conclusion according to my planed way of operation is the following setup 2 pcs KFL3A-2.8_2.7sw replacement K3 and KRX3 2 pcs KFL3A-1.8K SSB 2 pcs KFL3A-200 5-pole CW + matching 2 pcs KFL3A-400 CW 2 pcs KFL3B-FM FM For the purpose of working as many DXCC countries as possible including picking new ones during contests on crowded bands. As I understand this configuration will not allow me to receive or transmit on AM but it will maybe allow ESSB later if the firmware can be modified to use the FM filter for ESSB. Any further comments before my ordering will be appreciated. Vy 73 OZ1CCM Kjeld -Original Message- From: elecraft-boun...@mailman.qth.net [mailto:elecraft-boun...@mailman.qth.net] On Behalf Of Kjeld Holm Sent: 5. februar 2009 17:27 To: elecraft@mailman.qth.net Subject: Re: [Elecraft] [K3] Elecraft roofing filters Dear all, Thanks for all the kind answers. Sorry for all that fuss. Somehow I mixed up everything so I ended up thinking of some nonsense like 1.0 kHz for SSB. :-o I will go for 250 Hz and 400 Hz for CW plus 2.8 kHz for SSB. And also filters for AM and FM. Vy 73 OZ1CCM Kjeld -Original Message- From: W0MU Mike Fatchett [mailto:w...@w0mu.com] Sent: 5. februar 2009 15:28 To: 'Kjeld Holm' Subject: RE: [Elecraft] [K3] Elecraft roofing filters They are available on the website. KFL3A-1.0K 1 kHz, 8-pole roofing filter125.95 I have one in my K3 but I don't use it too much. You might want to use it over a 250 or 500 filter to listen to a pile up so you can hear if the station is working people above or below his frequency. I have listened to SSB a bit on the filter and while very narrow for SSB you can hear the station. The better question might be, what modes do you like to operate? I am about to order a second K3 and I was going to go with the following filters. 2.8 replacing the stock 2.7/ AM/ FM/ 400 or 500 and 250. If you never play to transmit on AM or want to do ESSB or FM those slots would be available. The K3 I have now has the 2.7 which is being replaced with the 2.8/1.8/1.0/400/200 in the main rcv, 2.8/400 in the sub. Mike W0MU A slip of the foot you may soon recover, but a slip of the tongue you may never get over. Ben Franklin -Original Message- From: elecraft-boun...@mailman.qth.net [mailto:elecraft-boun...@mailman.qth.net] On Behalf Of Kjeld Holm Sent: Thursday, February 05, 2009 5:44 AM To: 'ElecraftList' Subject: [Elecraft] [K3] Elecraft roofing filters Dear all, In the Roofing Filter Notes from Wayne and Eric link on the Order page I see the two sentences: Add narrower/wider filters as you prefer. I like to use the 1.0 kHz crystal filter when tuning a crowded band or listening to a pile up. Can anyone point me to a place that can tell me what the 1.0 kHz crystal filter is, where to obtain one and when it is worth using? Vy 73 OZ1CCM Kjeld __ 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 __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft
Re: [Elecraft] [K3] Elecraft roofing filters
Quoted discussion from K2AV and W4TV: Anyone who asks us what filters to buy for CW contesting, we tell them 400/250 8 pole set to 450/350. Tried and true, not theory. W4TV and I will just have to agree to disagree. I don't think there is any disagreement ... unless you have actually tried a 400/200 pair set to 450/250 and are trying to say that the 250 Hz filter is tighter and suffers fewer hardware AGC effects than the 200 Hz filter. If you try to make that point, there are several others including W4ZV, who will disagree with you. 73, ... Joe, W4TV The data I measured for the -30 dB down BW's of my 200 and 250 Hz filters supports what Joe says: 430 Hz for the 200 Hz 5-pole versus 500 Hz for the 250 Hz 8-pole. As a nearly 100% CW operator, I do like having three CW roofing filters in my rig. Matching DSP cutoff points to the various filters is another variable to play with, and thanks to Guy for the suggestions there. I do think there is a bit of a truth in labeling issue with regard to narrow crystal filters that needs to be addressed by the manufacturers. Not everybody will remember, for instance, that a 250 Hz filter may really have a bandwidth of 375 Hz. I recall a similar issue with a 125 Hz filter that I purchased for my TS-850S some years back. The filter curve supplied by the manufacturer showed it was actually considerably wider than that (more than 200 Hz, as I recall). I can understand the difficulty in manufacturing very high Q multiple pole crystal filters, and that there might have been a design goal in mind that wasn't met. However, once we know that the design goal wasn't met, shouldn't we revise our labelling to more accurately reflect real world results? 73, Chuck Guenther NI0C K2/10 s/n 5853 K3/100 s/n 1061 __ 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] Elecraft roofing filters
Right now my conclusion according to my planed way of operation is the following setup 2 pcs KFL3A-2.8_2.7sw replacement K3 and KRX3 2 pcs KFL3A-1.8K SSB 2 pcs KFL3A-200 5-pole CW + matching 2 pcs KFL3A-400 CW 2 pcs KFL3B-FM FM Having done the 2 x KFL3A-2.8_2.7sw replacement, I am not convinced that there is enough (any) performance gain to justify the significant cost. As others have commented, you probably don't need the extra FM, 1.8K and 200 Hz filters in the subreceiver. However, with the soon to be released independent band operation, the FM filter might be worthwhile to permit SWL or other general purpose listening. As I understand this configuration will not allow me to receive or transmit on AM but it will maybe allow ESSB later if the firmware can be modified to use the FM filter for ESSB. The FM filter will allow you to receive AM but not transmit at the present time. With the concern for transmit image rejection when using the FM filter in AM or ESSB, there is no reason that the filter could not be offset to place the image well down the skirt when transmitting if the skirts are marginal with the signal centered. 73, ... Joe, W4TV -Original Message- From: elecraft-boun...@mailman.qth.net [mailto:elecraft-boun...@mailman.qth.net] On Behalf Of Kjeld Holm Sent: Friday, February 06, 2009 3:32 AM To: elecraft@mailman.qth.net Subject: Re: [Elecraft] [K3] Elecraft roofing filters Dear all, Once and again: Thanks to all for very interesting and informative answers. Right now my conclusion according to my planed way of operation is the following setup 2 pcs KFL3A-2.8_2.7sw replacement K3 and KRX3 2 pcs KFL3A-1.8K SSB 2 pcs KFL3A-200 5-pole CW + matching 2 pcs KFL3A-400 CW 2 pcs KFL3B-FM FM For the purpose of working as many DXCC countries as possible including picking new ones during contests on crowded bands. As I understand this configuration will not allow me to receive or transmit on AM but it will maybe allow ESSB later if the firmware can be modified to use the FM filter for ESSB. Any further comments before my ordering will be appreciated. Vy 73 OZ1CCM Kjeld -Original Message- From: elecraft-boun...@mailman.qth.net [mailto:elecraft-boun...@mailman.qth.net] On Behalf Of Kjeld Holm Sent: 5. februar 2009 17:27 To: elecraft@mailman.qth.net Subject: Re: [Elecraft] [K3] Elecraft roofing filters Dear all, Thanks for all the kind answers. Sorry for all that fuss. Somehow I mixed up everything so I ended up thinking of some nonsense like 1.0 kHz for SSB. :-o I will go for 250 Hz and 400 Hz for CW plus 2.8 kHz for SSB. And also filters for AM and FM. Vy 73 OZ1CCM Kjeld -Original Message- From: W0MU Mike Fatchett [mailto:w...@w0mu.com] Sent: 5. februar 2009 15:28 To: 'Kjeld Holm' Subject: RE: [Elecraft] [K3] Elecraft roofing filters They are available on the website. KFL3A-1.0K 1 kHz, 8-pole roofing filter 125.95 I have one in my K3 but I don't use it too much. You might want to use it over a 250 or 500 filter to listen to a pile up so you can hear if the station is working people above or below his frequency. I have listened to SSB a bit on the filter and while very narrow for SSB you can hear the station. The better question might be, what modes do you like to operate? I am about to order a second K3 and I was going to go with the following filters. 2.8 replacing the stock 2.7/ AM/ FM/ 400 or 500 and 250. If you never play to transmit on AM or want to do ESSB or FM those slots would be available. The K3 I have now has the 2.7 which is being replaced with the 2.8/1.8/1.0/400/200 in the main rcv, 2.8/400 in the sub. Mike W0MU A slip of the foot you may soon recover, but a slip of the tongue you may never get over. Ben Franklin -Original Message- From: elecraft-boun...@mailman.qth.net [mailto:elecraft-boun...@mailman.qth.net] On Behalf Of Kjeld Holm Sent: Thursday, February 05, 2009 5:44 AM To: 'ElecraftList' Subject: [Elecraft] [K3] Elecraft roofing filters Dear all, In the Roofing Filter Notes from Wayne and Eric link on the Order page I see the two sentences: Add narrower/wider filters as you prefer. I like to use the 1.0 kHz crystal filter when tuning a crowded band or listening to a pile up. Can anyone point me to a place that can tell me what the 1.0 kHz crystal filter is, where to obtain one and when it is worth using? Vy 73 OZ1CCM Kjeld __ 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] Elecraft roofing filters
Does he really need two FM filters? If you want to do diversity receive make sure you ask for matching filters. I don't know if you really need all those filters in the sub receiver. I would assume most of your main operating would be off the main receiver. Mike W0MU A slip of the foot you may soon recover, but a slip of the tongue you may never get over. Ben Franklin -Original Message- From: elecraft-boun...@mailman.qth.net [mailto:elecraft-boun...@mailman.qth.net] On Behalf Of Kjeld Holm Sent: Friday, February 06, 2009 1:32 AM To: elecraft@mailman.qth.net Subject: Re: [Elecraft] [K3] Elecraft roofing filters Dear all, Once and again: Thanks to all for very interesting and informative answers. Right now my conclusion according to my planed way of operation is the following setup 2 pcs KFL3A-2.8_2.7sw replacement K3 and KRX3 2 pcs KFL3A-1.8K SSB 2 pcs KFL3A-200 5-pole CW + matching 2 pcs KFL3A-400 CW 2 pcs KFL3B-FM FM For the purpose of working as many DXCC countries as possible including picking new ones during contests on crowded bands. As I understand this configuration will not allow me to receive or transmit on AM but it will maybe allow ESSB later if the firmware can be modified to use the FM filter for ESSB. Any further comments before my ordering will be appreciated. Vy 73 OZ1CCM Kjeld -Original Message- From: elecraft-boun...@mailman.qth.net [mailto:elecraft-boun...@mailman.qth.net] On Behalf Of Kjeld Holm Sent: 5. februar 2009 17:27 To: elecraft@mailman.qth.net Subject: Re: [Elecraft] [K3] Elecraft roofing filters Dear all, Thanks for all the kind answers. Sorry for all that fuss. Somehow I mixed up everything so I ended up thinking of some nonsense like 1.0 kHz for SSB. :-o I will go for 250 Hz and 400 Hz for CW plus 2.8 kHz for SSB. And also filters for AM and FM. Vy 73 OZ1CCM Kjeld -Original Message- From: W0MU Mike Fatchett [mailto:w...@w0mu.com] Sent: 5. februar 2009 15:28 To: 'Kjeld Holm' Subject: RE: [Elecraft] [K3] Elecraft roofing filters They are available on the website. KFL3A-1.0K 1 kHz, 8-pole roofing filter125.95 I have one in my K3 but I don't use it too much. You might want to use it over a 250 or 500 filter to listen to a pile up so you can hear if the station is working people above or below his frequency. I have listened to SSB a bit on the filter and while very narrow for SSB you can hear the station. The better question might be, what modes do you like to operate? I am about to order a second K3 and I was going to go with the following filters. 2.8 replacing the stock 2.7/ AM/ FM/ 400 or 500 and 250. If you never play to transmit on AM or want to do ESSB or FM those slots would be available. The K3 I have now has the 2.7 which is being replaced with the 2.8/1.8/1.0/400/200 in the main rcv, 2.8/400 in the sub. Mike W0MU A slip of the foot you may soon recover, but a slip of the tongue you may never get over. Ben Franklin -Original Message- From: elecraft-boun...@mailman.qth.net [mailto:elecraft-boun...@mailman.qth.net] On Behalf Of Kjeld Holm Sent: Thursday, February 05, 2009 5:44 AM To: 'ElecraftList' Subject: [Elecraft] [K3] Elecraft roofing filters Dear all, In the Roofing Filter Notes from Wayne and Eric link on the Order page I see the two sentences: Add narrower/wider filters as you prefer. I like to use the 1.0 kHz crystal filter when tuning a crowded band or listening to a pile up. Can anyone point me to a place that can tell me what the 1.0 kHz crystal filter is, where to obtain one and when it is worth using? Vy 73 OZ1CCM Kjeld __ 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 __ 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] Elecraft roofing filters
Kleld there has been some debate over the use of FM bandwidth filtering to transmit AM (or ESSB), I don't have an FM filter so cannot give a measurement for the bandwidth that may result from transmitting AM or ESSB through the filter. Using the 6 KHz AM filter gives a nice tight transmission on AM with a bandwidth of approximately +/- 3KHz down to many dB's below peak. ESSB through the 6 KHz filter is also nice and tight. There are some excessively wide AM transmissions here in the UK on AM, several have been measured at +/- 10 KHz or more, these are usually older, or home built, transmitters rather than recent commercial units. AM can use excessive bandwidth so I would hope K3 users would set a good example and keep their transmissions within reasonable limits. Bottom line, if you want to transmit AM or ESSB consider using the 6 KHz rather than the 13 KHz filter unless you can be sure your bandwidth isn't excessive with one. 73 Dave, G4AON K3/100 #80 SNIP 2 pcs KFL3A-2.8_2.7sw replacement K3 and KRX3 2 pcs KFL3A-1.8K SSB 2 pcs KFL3A-200 5-pole CW + matching 2 pcs KFL3A-400 CW 2 pcs KFL3B-FM FM For the purpose of working as many DXCC countries as possible including picking new ones during contests on crowded bands. As I understand this configuration will not allow me to receive or transmit on AM but it will maybe allow ESSB later if the firmware can be modified to use the FM filter for ESSB. Any further comments before my ordering will be appreciated. Vy 73 OZ1CCM Kjeld __ 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] Elecraft roofing filters
On the K3 order page you will find: KFL3A-1.0K 1 kHz, 8-pole roofing filter _ From: elecraft-boun...@mailman.qth.net [mailto:elecraft-boun...@mailman.qth.net] On Behalf Of Kjeld Holm Sent: Thursday, February 05, 2009 6:44 AM To: 'ElecraftList' Subject: [Elecraft] [K3] Elecraft roofing filters Dear all, In the Roofing Filter Notes from Wayne and Eric link on the Order page I see the two sentences: Add narrower/wider filters as you prefer. I like to use the 1.0 kHz crystal filter when tuning a crowded band or listening to a pile up. Can anyone point me to a place that can tell me what the 1.0 kHz crystal filter is, where to obtain one and when it is worth using? Vy 73 OZ1CCM Kjeld __ 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] [K3] Elecraft roofing filters
Dear all, In the Roofing Filter Notes from Wayne and Eric link on the Order page I see the two sentences: Add narrower/wider filters as you prefer. I like to use the 1.0 kHz crystal filter when tuning a crowded band or listening to a pile up. Can anyone point me to a place that can tell me what the 1.0 kHz crystal filter is, where to obtain one and when it is worth using? Vy 73 OZ1CCM Kjeld __ 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] Elecraft roofing filters
Dear all, Thanks for all the kind answers. Sorry for all that fuss. Somehow I mixed up everything so I ended up thinking of some nonsense like 1.0 kHz for SSB. :-o I will go for 250 Hz and 400 Hz for CW plus 2.8 kHz for SSB. And also filters for AM and FM. Vy 73 OZ1CCM Kjeld -Original Message- From: W0MU Mike Fatchett [mailto:w...@w0mu.com] Sent: 5. februar 2009 15:28 To: 'Kjeld Holm' Subject: RE: [Elecraft] [K3] Elecraft roofing filters They are available on the website. KFL3A-1.0K 1 kHz, 8-pole roofing filter125.95 I have one in my K3 but I don't use it too much. You might want to use it over a 250 or 500 filter to listen to a pile up so you can hear if the station is working people above or below his frequency. I have listened to SSB a bit on the filter and while very narrow for SSB you can hear the station. The better question might be, what modes do you like to operate? I am about to order a second K3 and I was going to go with the following filters. 2.8 replacing the stock 2.7/ AM/ FM/ 400 or 500 and 250. If you never play to transmit on AM or want to do ESSB or FM those slots would be available. The K3 I have now has the 2.7 which is being replaced with the 2.8/1.8/1.0/400/200 in the main rcv, 2.8/400 in the sub. Mike W0MU A slip of the foot you may soon recover, but a slip of the tongue you may never get over. Ben Franklin -Original Message- From: elecraft-boun...@mailman.qth.net [mailto:elecraft-boun...@mailman.qth.net] On Behalf Of Kjeld Holm Sent: Thursday, February 05, 2009 5:44 AM To: 'ElecraftList' Subject: [Elecraft] [K3] Elecraft roofing filters Dear all, In the Roofing Filter Notes from Wayne and Eric link on the Order page I see the two sentences: Add narrower/wider filters as you prefer. I like to use the 1.0 kHz crystal filter when tuning a crowded band or listening to a pile up. Can anyone point me to a place that can tell me what the 1.0 kHz crystal filter is, where to obtain one and when it is worth using? Vy 73 OZ1CCM Kjeld __ 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] Elecraft roofing filters
I have the 400 and don't see the need for 250 --Original Message-- From: Kjeld Holm Sender: elecraft-boun...@mailman.qth.net To: elecraft@mailman.qth.net Subject: Re: [Elecraft] [K3] Elecraft roofing filters Sent: Feb 5, 2009 11:27 AM Dear all, Thanks for all the kind answers. Sorry for all that fuss. Somehow I mixed up everything so I ended up thinking of some nonsense like 1.0 kHz for SSB. :-o I will go for 250 Hz and 400 Hz for CW plus 2.8 kHz for SSB. And also filters for AM and FM. Vy 73 OZ1CCM Kjeld -Original Message- From: W0MU Mike Fatchett [mailto:w...@w0mu.com] Sent: 5. februar 2009 15:28 To: 'Kjeld Holm' Subject: RE: [Elecraft] [K3] Elecraft roofing filters They are available on the website. KFL3A-1.0K 1 kHz, 8-pole roofing filter125.95 I have one in my K3 but I don't use it too much. You might want to use it over a 250 or 500 filter to listen to a pile up so you can hear if the station is working people above or below his frequency. I have listened to SSB a bit on the filter and while very narrow for SSB you can hear the station. The better question might be, what modes do you like to operate? I am about to order a second K3 and I was going to go with the following filters. 2.8 replacing the stock 2.7/ AM/ FM/ 400 or 500 and 250. If you never play to transmit on AM or want to do ESSB or FM those slots would be available. The K3 I have now has the 2.7 which is being replaced with the 2.8/1.8/1.0/400/200 in the main rcv, 2.8/400 in the sub. Mike W0MU A slip of the foot you may soon recover, but a slip of the tongue you may never get over. Ben Franklin -Original Message- From: elecraft-boun...@mailman.qth.net [mailto:elecraft-boun...@mailman.qth.net] On Behalf Of Kjeld Holm Sent: Thursday, February 05, 2009 5:44 AM To: 'ElecraftList' Subject: [Elecraft] [K3] Elecraft roofing filters Dear all, In the Roofing Filter Notes from Wayne and Eric link on the Order page I see the two sentences: Add narrower/wider filters as you prefer. I like to use the 1.0 kHz crystal filter when tuning a crowded band or listening to a pile up. Can anyone point me to a place that can tell me what the 1.0 kHz crystal filter is, where to obtain one and when it is worth using? Vy 73 OZ1CCM Kjeld __ 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 Sent from my Verizon Wireless BlackBerry __ 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] Elecraft roofing filters
I agree with that, but the 1.8kHz sure helps in SSB Contests 73 de M0XDF, K3 #174 -- Mathematics is the language with which God has written the universe. -Galileo Galilei, physicist and astronomer (1564-1642) On 5 Feb 2009, at 16:53, k...@verizon.net wrote: I have the 400 and don't see the need for 250 --Original Message-- From: Kjeld Holm Sender: elecraft-boun...@mailman.qth.net To: elecraft@mailman.qth.net Subject: Re: [Elecraft] [K3] Elecraft roofing filters Sent: Feb 5, 2009 11:27 AM Dear all, Thanks for all the kind answers. Sorry for all that fuss. Somehow I mixed up everything so I ended up thinking of some nonsense like 1.0 kHz for SSB. :-o I will go for 250 Hz and 400 Hz for CW plus 2.8 kHz for SSB. And also filters for AM and FM. Vy 73 OZ1CCM Kjeld __ 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] Elecraft roofing filters
The 250Hz and 400Hz filters are very similar, in reality. Having both is redundant. But having a 1.8kHz or 2.1kHz for SSB RX is a good thing for contesting. Note that some people have used a custom 1.5kHz roofing filter with good success for SSB contesting. This is all from a little experience, and listening to people with LOTS of experince and knowledge. 73, doug From: David Ferrington, M0XDF m0...@alphadene.co.uk Date: Thu, 5 Feb 2009 17:46:52 + I agree with that, but the 1.8kHz sure helps in SSB Contests 73 de M0XDF, K3 #174 -- Mathematics is the language with which God has written the universe. -Galileo Galilei, physicist and astronomer (1564-1642) On 5 Feb 2009, at 16:53, k...@verizon.net wrote: I have the 400 and don't see the need for 250 --Original Message-- From: Kjeld Holm Sender: elecraft-boun...@mailman.qth.net To: elecraft@mailman.qth.net Subject: Re: [Elecraft] [K3] Elecraft roofing filters Sent: Feb 5, 2009 11:27 AM Dear all, Thanks for all the kind answers. Sorry for all that fuss. Somehow I mixed up everything so I ended up thinking of some nonsense like 1.0 kHz for SSB. :-o I will go for 250 Hz and 400 Hz for CW plus 2.8 kHz for SSB. And also filters for AM and FM. Vy 73 OZ1CCM Kjeld __ 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] Elecraft roofing filters
I will go for 250 Hz and 400 Hz for CW plus 2.8 kHz for SSB. And also filters for AM and FM. The difference between the 250 and 400 Hz filters is not enough to be worthwhile (approximately 375 Hz vs. 430 Hz). If you want a narrow filter get the Elecraft 200 Hz 5-pole unit. In addition, you should not need both the FM and AM filters if the firmware was fixed to allow the use of the FM filter for ESSB and AM transmit. If you plan to use the AM filter only for receiving, that is even more reason to bypass the AM roofer and leave a space for the 1.5 or 1.8 KHz SSB filter. 73, ... Joe, W4TV --Original Message-- From: Kjeld Holm Sender: elecraft-boun...@mailman.qth.net To: elecraft@mailman.qth.net Subject: Re: [Elecraft] [K3] Elecraft roofing filters Sent: Feb 5, 2009 11:27 AM Dear all, Thanks for all the kind answers. Sorry for all that fuss. Somehow I mixed up everything so I ended up thinking of some nonsense like 1.0 kHz for SSB. :-o I will go for 250 Hz and 400 Hz for CW plus 2.8 kHz for SSB. And also filters for AM and FM. Vy 73 OZ1CCM Kjeld __ 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] Elecraft roofing filters
The 250Hz and 400Hz filters are very similar, in reality. Having both is redundant. But having a 1.8kHz or 2.1kHz for SSB RX is a good thing for contesting. Note that some people have used a custom 1.5kHz roofing filter with good success for SSB contesting. I have to agree with Doug on this, get either one, but not both. I have both the 400Hz and 250Hz and I saw little difference between them. When I installed my KRX3 I took the 400hz filter out of the main receiver and moved it over to the 2nd receiver. I am happy the way it works now. So, that's 2.7Khz and 250Hz for the main receiver and 2.7Khz and 400Hz for the sub. Diversity receive still works fine. YMMV. Andreas, N6NU __ 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] [K3] Elecraft roofing filters
W4TV wrote: The difference between the 250 and 400 Hz filters is not enough to be worthwhile (approximately 375 Hz vs. 430 Hz). Joe, what is your source for these numbers? I've seen numbers like this mentioned previously on the reflector. I recently tested my K3 CW roofing filters using the XG-2 generator at 7040 KHz (50 microvolts input) and KS7D's nice software package, K3 Filter Tools. Here's what I came up with, with AGC off and with the DSP bandwidth set at least as wide as 900 Hz for all tests (to isolate the effects of just the crystal roofing filter): 200 Hz, 5-pole: -6 dB BW = 210 Hz; -30 dB BW = 430 Hz 250 Hz, 8-pole: -6 dB BW = 260 Hz; -30 dB BW = 500 Hz 400 Hz, 8-pole: -6 dB BW = 380 Hz; -30 dB BW = 580 Hz Note the uncertainty in each of the bandwidths above is plus or minus 20 Hz, because I ran these sweeps in 10 Hz increments to save time. (I'll repeat these tests using a 1 or 2 Hz increment, when I have some spare time.) These tests on my filters (as well as my experience by ear) indicate there is an appreciable difference in the 250 and 400 Hz 8-pole filters. I've always wondered, too, about manufacturing tolerances on narrow crystal filters. 73, Chuck Guenther NI0C __ 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] Elecraft roofing filters
The difference between the 250 and 400 Hz filters is not enough to be worthwhile (approximately 375 Hz vs. 430 Hz). Joe, what is your source for these numbers? I've seen numbers like this mentioned previously on the reflector. My source is Elecraft: www.elecraft.com/K3/K3_8_pole_plots.htm Look specifically at the last two plots which show: KFL3A-400 KFL3A-250 -6 dB 435 Hz 370 Hz -60 dB 935 Hz 785 Hz SF2.15:1 2.12:1 INRAD do not publish the curves for the Elecraft (or Yaesu 8215 KHz) 250 Hz filter. However, they do show the curve for the 8830 KHz (Kenwood) version of the same filter and it shows a similar percentage bandwidth (367.5/845 Hz at -6/60dB). Here's what I came up with, with AGC off and with the DSP bandwidth set at least as wide as 900 Hz for all tests (to isolate the effects of just the crystal roofing filter): 200 Hz, 5-pole: -6 dB BW = 210 Hz; -30 dB BW = 430 Hz 250 Hz, 8-pole: -6 dB BW = 260 Hz; -30 dB BW = 500 Hz 400 Hz, 8-pole: -6 dB BW = 380 Hz; -30 dB BW = 580 Hz Did you run those tests in a Data mode or with the CW pitch set to 800 Hz? If not, the low frequency skirts will be sharpened significantly and the measured bandwidth will less than the roofing filter. With a CW pitch of 560 Hz I measure 10% less bandwidth than in DATA (CF = 1500 Hz or 2210 Hz). If I reduce the pitch to 300 Hz, the measured bandwidth is further reduced (due to the DSP filter's low frequency cut-off). 73, ... Joe, W4TV -Original Message- From: elecraft-boun...@mailman.qth.net [mailto:elecraft-boun...@mailman.qth.net] On Behalf Of ni0c Sent: Thursday, February 05, 2009 3:47 PM To: elecraft@mailman.qth.net Subject: [Elecraft] [K3] Elecraft roofing filters W4TV wrote: The difference between the 250 and 400 Hz filters is not enough to be worthwhile (approximately 375 Hz vs. 430 Hz). Joe, what is your source for these numbers? I've seen numbers like this mentioned previously on the reflector. I recently tested my K3 CW roofing filters using the XG-2 generator at 7040 KHz (50 microvolts input) and KS7D's nice software package, K3 Filter Tools. Here's what I came up with, with AGC off and with the DSP bandwidth set at least as wide as 900 Hz for all tests (to isolate the effects of just the crystal roofing filter): 200 Hz, 5-pole: -6 dB BW = 210 Hz; -30 dB BW = 430 Hz 250 Hz, 8-pole: -6 dB BW = 260 Hz; -30 dB BW = 500 Hz 400 Hz, 8-pole: -6 dB BW = 380 Hz; -30 dB BW = 580 Hz Note the uncertainty in each of the bandwidths above is plus or minus 20 Hz, because I ran these sweeps in 10 Hz increments to save time. (I'll repeat these tests using a 1 or 2 Hz increment, when I have some spare time.) These tests on my filters (as well as my experience by ear) indicate there is an appreciable difference in the 250 and 400 Hz 8-pole filters. I've always wondered, too, about manufacturing tolerances on narrow crystal filters. 73, Chuck Guenther NI0C __ 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] Elecraft roofing filters
W4TV wrote: My source is Elecraft: www.elecraft.com/K3/K3_8_pole_plots.htm Look specifically at the last two plots which show: KFL3A-400 KFL3A-250 -6 dB 435 Hz 370 Hz -60 dB 935 Hz 785 Hz SF2.15:1 2.12:1 INRAD do not publish the curves for the Elecraft (or Yaesu 8215 KHz) 250 Hz filter. However, they do show the curve for the 8830 KHz (Kenwood) version of the same filter and it shows a similar percentage bandwidth (367.5/845 Hz at -6/60dB). NI0C responds: I'm still wondering what the tolerance is on such published curves. Did you run those tests in a Data mode or with the CW pitch set to 800 Hz? If not, the low frequency skirts will be sharpened significantly and the measured bandwidth will less than the roofing filter. With a CW pitch of 560 Hz I measure 10% less bandwidth than in DATA (CF = 1500 Hz or 2210 Hz). If I reduce the pitch to 300 Hz, the measured bandwidth is further reduced (due to the DSP filter's low frequency cut-off). 73, ... Joe, W4TV NI0C responds: My testing was done in CW mode with the pitch in the low 300's (320 Hz, as I recall). So, when I repeat the tests, I'll vary the pitch and see what happens, say 300 Hz, 600 hz, and 800 Hz. 73 Thanks, Joe, for your info! Chuck Guenther NI0C __ 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] Elecraft roofing filters
ni0c wrote: My testing was done in CW mode with the pitch in the low 300's (320 Hz, as I recall). So, when I repeat the tests, I'll vary the pitch and see what happens, say 300 Hz, 600 hz, and 800 Hz. Another person who likes a low pitch! This really affects what you will hear because the MCU firmware shifts the bandpass so that the low end always truncates at ~200 Hz. If you use a nominal 500 Hz filter, this means it will be positioned from 200-700 Hz, so you'll hear signals 400 Hz above your zero beat frequency of 300. This would be equivalent to an 800 Hz filter if centered. The K3 operates differently from Orion which I know you had before. This is exactly why I sold my 1000 Hz filter. With a nominal bandwidth of 1100 Hz and 300 Hz PITCH, I was hearing signals 1 kHz above my zero beat QRG (i.e. my actual bandpass was 200-1300 Hz). 1 kHz above my QRG is not practical on any sort of crowded band. If the band is not crowded with strong signals then the stock 2.7k filter is about as effective. 73, Bill -- View this message in context: http://n2.nabble.com/Elecraft-roofing-filters-tp2277174p2278065.html Sent from the [K3] mailing list archive at Nabble.com. __ 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] Elecraft roofing filters
I'm still wondering what the tolerance is on such published curves. I would not be so much concerned about tolerance as sampling error on the curves. Still, the Elecraft curves are generally similar to those given by INRAD for the same filter or those with a similar (e.g., 8215 or 8830 KHz) center frequency and bandwidth. For example, Inrad's curves for the KFL3A-2.1K KFL3A-1.0 are identical to those from Elecraft ... Inrad's curves are wider for the KFL3A-6K KFL3A-400 and Elecraft's cure is wider for the KFL3A-1.8K. (Inrad does not publish curves for the KFL3A-2.8K or KFL3A-250 ... nor do they have any information on the 1500 and 500 Hz custom filters) My testing was done in CW mode with the pitch in the low 300's (320 Hz, as I recall). The DSP begins to roll off at 200 Hz even if LO = 0.00. Any measurement where FC (Pitch) is less than [BW60/2 + 200] will be inaccurate on the skirts and any measurement where FC is less than BW6/2 + 200 will have essentially identical lower frequency responses. 73, ... Joe, W4TV -Original Message- From: ni0c [mailto:n...@earthlink.net] Sent: Thursday, February 05, 2009 5:42 PM To: li...@subich.com; elecraft@mailman.qth.net Subject: Re: [Elecraft] [K3] Elecraft roofing filters W4TV wrote: My source is Elecraft: www.elecraft.com/K3/K3_8_pole_plots.htm Look specifically at the last two plots which show: KFL3A-400 KFL3A-250 -6 dB 435 Hz 370 Hz -60 dB 935 Hz 785 Hz SF2.15:1 2.12:1 INRAD do not publish the curves for the Elecraft (or Yaesu 8215 KHz) 250 Hz filter. However, they do show the curve for the 8830 KHz (Kenwood) version of the same filter and it shows a similar percentage bandwidth (367.5/845 Hz at -6/60dB). NI0C responds: I'm still wondering what the tolerance is on such published curves. Did you run those tests in a Data mode or with the CW pitch set to 800 Hz? If not, the low frequency skirts will be sharpened significantly and the measured bandwidth will less than the roofing filter. With a CW pitch of 560 Hz I measure 10% less bandwidth than in DATA (CF = 1500 Hz or 2210 Hz). If I reduce the pitch to 300 Hz, the measured bandwidth is further reduced (due to the DSP filter's low frequency cut-off). 73, ... Joe, W4TV NI0C responds: My testing was done in CW mode with the pitch in the low 300's (320 Hz, as I recall). So, when I repeat the tests, I'll vary the pitch and see what happens, say 300 Hz, 600 hz, and 800 Hz. 73 Thanks, Joe, for your info! Chuck Guenther NI0C __ 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] Elecraft roofing filters
Having used three different K3's equipped with 4 different sets of 250 400 hz 8 poles in overload city major contests, the usefulness of these filters is belied by the apparent closeness of numbers. In practice we have found that associating the 400 with a DSP width of 450, and the 250 with a DSP width of 350 has been extremely useful, however too close by the numbers that may look on paper. We use 450 for running for as long as it may last, and when the inevitable 30 over 9 crowder squeezes down on us, I reduce to 350 and if that isn't enough, *ADDITIONALLY* shift the center away 50 hz more. This combination plus the noise blanker for key clicks has worked extremely well. (Having 50 Hz granularity on the CW shift/widths would be *SO* useful here...) I have measured the combined (roofing+DSP) drop on the steepest part of the skirts at ~12 db per 10 Hz with these two 8 pole filters. So bringing in the skirt only 30 or 40 Hz is enough to push down the crowder quite a bit, usually well out of hardware AGC, without narrowing the listening window to the point of missing QSO points and multipliers from all the inevitable off-frequency callers. Anyone who asks us what filters to buy for CW contesting, we tell them 400/250 8 pole set to 450/350. Tried and true, not theory. W4TV and I will just have to agree to disagree. 73, Guy. - Original Message - From: ni0c To: elecraft@mailman.qth.net Sent: Thursday, February 05, 2009 4:47 PM Subject: [Elecraft] [K3] Elecraft roofing filters W4TV wrote: The difference between the 250 and 400 Hz filters is not enough to be worthwhile (approximately 375 Hz vs. 430 Hz). Joe, what is your source for these numbers? I've seen numbers like this mentioned previously on the reflector. I recently tested my K3 CW roofing filters using the XG-2 generator at 7040 KHz (50 microvolts input) and KS7D's nice software package, K3 Filter Tools. Here's what I came up with, with AGC off and with the DSP bandwidth set at least as wide as 900 Hz for all tests (to isolate the effects of just the crystal roofing filter): 200 Hz, 5-pole: -6 dB BW = 210 Hz; -30 dB BW = 430 Hz 250 Hz, 8-pole: -6 dB BW = 260 Hz; -30 dB BW = 500 Hz 400 Hz, 8-pole: -6 dB BW = 380 Hz; -30 dB BW = 580 Hz Note the uncertainty in each of the bandwidths above is plus or minus 20 Hz, because I ran these sweeps in 10 Hz increments to save time. (I'll repeat these tests using a 1 or 2 Hz increment, when I have some spare time.) These tests on my filters (as well as my experience by ear) indicate there is an appreciable difference in the 250 and 400 Hz 8-pole filters. I've always wondered, too, about manufacturing tolerances on narrow crystal filters. 73, Chuck Guenther NI0C -- __ 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] Elecraft roofing filters
That's a wish for 10 Hz shift/width below, not 50 :) - Original Message - From: Guy Olinger, K2AV To: ni0c ; elecraft@mailman.qth.net Sent: Tuesday, August 04, 2009 10:14 PM Subject: Re: [Elecraft] [K3] Elecraft roofing filters Having used three different K3's equipped with 4 different sets of 250 400 hz 8 poles in overload city major contests, the usefulness of these filters is belied by the apparent closeness of numbers. In practice we have found that associating the 400 with a DSP width of 450, and the 250 with a DSP width of 350 has been extremely useful, however too close by the numbers that may look on paper. We use 450 for running for as long as it may last, and when the inevitable 30 over 9 crowder squeezes down on us, I reduce to 350 and if that isn't enough, *ADDITIONALLY* shift the center away 50 hz more. This combination plus the noise blanker for key clicks has worked extremely well. (Having 50 Hz granularity on the CW shift/widths would be *SO* useful here...) I have measured the combined (roofing+DSP) drop on the steepest part of the skirts at ~12 db per 10 Hz with these two 8 pole filters. So bringing in the skirt only 30 or 40 Hz is enough to push down the crowder quite a bit, usually well out of hardware AGC, without narrowing the listening window to the point of missing QSO points and multipliers from all the inevitable off-frequency callers. Anyone who asks us what filters to buy for CW contesting, we tell them 400/250 8 pole set to 450/350. Tried and true, not theory. W4TV and I will just have to agree to disagree. 73, Guy. - Original Message - From: ni0c To: elecraft@mailman.qth.net Sent: Thursday, February 05, 2009 4:47 PM Subject: [Elecraft] [K3] Elecraft roofing filters W4TV wrote: The difference between the 250 and 400 Hz filters is not enough to be worthwhile (approximately 375 Hz vs. 430 Hz). Joe, what is your source for these numbers? I've seen numbers like this mentioned previously on the reflector. I recently tested my K3 CW roofing filters using the XG-2 generator at 7040 KHz (50 microvolts input) and KS7D's nice software package, K3 Filter Tools. Here's what I came up with, with AGC off and with the DSP bandwidth set at least as wide as 900 Hz for all tests (to isolate the effects of just the crystal roofing filter): 200 Hz, 5-pole: -6 dB BW = 210 Hz; -30 dB BW = 430 Hz 250 Hz, 8-pole: -6 dB BW = 260 Hz; -30 dB BW = 500 Hz 400 Hz, 8-pole: -6 dB BW = 380 Hz; -30 dB BW = 580 Hz Note the uncertainty in each of the bandwidths above is plus or minus 20 Hz, because I ran these sweeps in 10 Hz increments to save time. (I'll repeat these tests using a 1 or 2 Hz increment, when I have some spare time.) These tests on my filters (as well as my experience by ear) indicate there is an appreciable difference in the 250 and 400 Hz 8-pole filters. I've always wondered, too, about manufacturing tolerances on narrow crystal filters. 73, Chuck Guenther NI0C __ 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__ 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] Elecraft roofing filters
Having used three different K3's equipped with 4 different sets of 250 400 hz 8 poles in overload city major contests, the usefulness of these filters is belied by the apparent closeness of numbers. I'm happy that you are finding success with the 400/250 filter pair but given the published specifications I suspect your results have more to do with the DSP performance than the actual width of the 250 Hz filter. There is so little difference in the published curves for the two filters (150 Hz at -60 dB) that roofing filter performance alone can not be responsible for the differences performance you describe. If one is looking for improved narrow CW performance, the 400/200 combination is a more effective and cost efficient pairing. Anyone who asks us what filters to buy for CW contesting, we tell them 400/250 8 pole set to 450/350. Tried and true, not theory. W4TV and I will just have to agree to disagree. I don't think there is any disagreement ... unless you have actually tried a 400/200 pair set to 450/250 and are trying to say that the 250 Hz filter is tighter and suffers fewer hardware AGC effects than the 200 Hz filter. If you try to make that point, there are several others including W4ZV, who will disagree with you. 73, ... Joe, W4TV -Original Message- From: elecraft-boun...@mailman.qth.net [mailto:elecraft-boun...@mailman.qth.net] On Behalf Of Guy Olinger, K2AV Sent: Tuesday, August 04, 2009 10:14 PM To: ni0c; elecraft@mailman.qth.net Subject: Re: [Elecraft] [K3] Elecraft roofing filters Having used three different K3's equipped with 4 different sets of 250 400 hz 8 poles in overload city major contests, the usefulness of these filters is belied by the apparent closeness of numbers. In practice we have found that associating the 400 with a DSP width of 450, and the 250 with a DSP width of 350 has been extremely useful, however too close by the numbers that may look on paper. We use 450 for running for as long as it may last, and when the inevitable 30 over 9 crowder squeezes down on us, I reduce to 350 and if that isn't enough, *ADDITIONALLY* shift the center away 50 hz more. This combination plus the noise blanker for key clicks has worked extremely well. (Having 50 Hz granularity on the CW shift/widths would be *SO* useful here...) I have measured the combined (roofing+DSP) drop on the steepest part of the skirts at ~12 db per 10 Hz with these two 8 pole filters. So bringing in the skirt only 30 or 40 Hz is enough to push down the crowder quite a bit, usually well out of hardware AGC, without narrowing the listening window to the point of missing QSO points and multipliers from all the inevitable off-frequency callers. Anyone who asks us what filters to buy for CW contesting, we tell them 400/250 8 pole set to 450/350. Tried and true, not theory. W4TV and I will just have to agree to disagree. 73, Guy. - Original Message - From: ni0c To: elecraft@mailman.qth.net Sent: Thursday, February 05, 2009 4:47 PM Subject: [Elecraft] [K3] Elecraft roofing filters W4TV wrote: The difference between the 250 and 400 Hz filters is not enough to be worthwhile (approximately 375 Hz vs. 430 Hz). Joe, what is your source for these numbers? I've seen numbers like this mentioned previously on the reflector. I recently tested my K3 CW roofing filters using the XG-2 generator at 7040 KHz (50 microvolts input) and KS7D's nice software package, K3 Filter Tools. Here's what I came up with, with AGC off and with the DSP bandwidth set at least as wide as 900 Hz for all tests (to isolate the effects of just the crystal roofing filter): 200 Hz, 5-pole: -6 dB BW = 210 Hz; -30 dB BW = 430 Hz 250 Hz, 8-pole: -6 dB BW = 260 Hz; -30 dB BW = 500 Hz 400 Hz, 8-pole: -6 dB BW = 380 Hz; -30 dB BW = 580 Hz Note the uncertainty in each of the bandwidths above is plus or minus 20 Hz, because I ran these sweeps in 10 Hz increments to save time. (I'll repeat these tests using a 1 or 2 Hz increment, when I have some spare time.) These tests on my filters (as well as my experience by ear) indicate there is an appreciable difference in the 250 and 400 Hz 8-pole filters. I've always wondered, too, about manufacturing tolerances on narrow crystal filters. 73, Chuck Guenther NI0C __ 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
