[Elecraft] CW roofing filters for the K3
W2KJ: Am wondering though if the Elecraft lab has made any measurements in comparing the performance of the 5 pole 500hz CW filter as opposed to the 8 pole 400hz CW filter. http://marc.info/?l=elecraftm=118970837128258w=2 Here you go! These are recent measurements from our lab. Filter20kHz 10kHz 5kHz 2kHz 200 Hz, 5 pole100+ 100+ 100+ 95 250 Hz, 8 pole100+ 100+ 100+ 95 400 Hz, 8 pole100+ 100+ 100+ 95 500 Hz, 5 pole100+ 100+ 100+ 94 1 kHz, 8 pole 100+ 100+ 10094 2.7 kHz, 5 pole 100+ 98 92n/a 2.8 kHz, 8 pole 100+ 100 93n/a These are typical numbers and may vary a couple of dB from radio to radio or filter to filter. 73, Eric WA6HHQ ___ 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] CW roofing filters for the K3
Believe I read that the DSP will make up for any loss caused by the 8 pole CW filter. When installing a crystal roofing filter in the K3, you enter a gain compensation amount in dB. The compensation is done by the DSP when that filter is in use. 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] CW roofing filters for the K3
Believe I read that the DSP will make up for any loss caused by the 8 pole CW filter. --- When installing a crystal roofing filter in the K3, you enter a gain compensation amount in dB. The compensation is done by the DSP when that filter is in use. --- Wait a minute. Does the act of putting in a specific filter tell DSP what compensation to do OR must we dumb operators try to guess at what compensation number to enter? And how would that number be entered? de Joe , aa4nn ___ 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] CW roofing filters for the K3
Believe I read that the DSP will make up for any loss caused by the 8 pole CW filter. --- When installing a crystal roofing filter in the K3, you enter a gain compensation amount in dB. The compensation is done by the DSP when that filter is in use. --- Wait a minute. Does the act of putting in a specific filter tell DSP what compensation to do OR must we dumb operators try to guess at what compensation number to enter? And how would that number be entered? This is covered fully in the K3 User Manual, available on the Elecraft web site. Refer to the crystal filter configuration section where it gives detailed instructions for adding a specific gain compensation value for any individual filter via the CONFIG menu. No gain compensation is needed except for the narrow filters, e.g., 400 Hz and 250 Hz. I use +2 dB and +3 dB respectively on those filters. I think the manual suggests 2-4 dB in general for the narrow 8-pole filters. Just set the compensation so there is no change in level as you switch through the wide and narrow filters. 73, Ed - W0YK ___ 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] CW roofing filters for the K3
AA4NN: Wait a minute. Does the act of putting in a specific filter tell DSP what compensation to do OR must we dumb operators try to guess at what compensation number to enter? And how would that number be entered? Read the manual for roofing filters. http://www.elecraft.com/manual/K3%20Crystal%20Filter%20Option%20Rev%20A.pdf 73, Bill W4ZV ___ 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] CW roofing filters for the K3
My K3 will be in the 2nd production run so I have some time to make a decision regarding CW roofing filters for the K3 as well as the 2700hz stock SSB filter . Am wondering though if the Elecraft lab has made any measurements in comparing the performance of the 5 pole 500hz CW filter as opposed to the 8 pole 400hz CW filter. Believe I read that the DSP will make up for any loss caused by the 8 pole CW filter. The Ten Tec Orion had a problem with the optional 500hz roofing filter in that when that filter was selected an amp was turned on to make up for the additional loss the filter causedin turn the IMD performance of the receiver suffered. I went to an Inrad filter (believe it is 5 pole) 600hz filter and plugged it into the 1000hz filter socket to get around this problem. My hope is that going to the 8 pole CW filter over the 5 pole CW filter won't cause a similiar problem in the K3 (I'm betting it won't but I would sure like to hear more about these filters to aid in my decision on which one to buy with the rig) Similiar info regarding replacing the stock 2700hz SSB filter with the 8 pole 2800hz filter would be most appreciated as well. Since there probably aren't too many K3's out there yet to get feedback on the above questions I would hope that the Elecraft lab folks could provide some qualitative information with numbers to allow comparisons to be made. 73, Joe W2KJ K2 owner and soon to be K3 owner ___ 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
