JT modes alignment
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Hello,
After successful use of JT65 with my KX3 overseas, I am back to my K2. According to the manual, the "r" mode is advised, because passband and ALC are optimized. (I never use RTTY) On my rig, the "r" mode, as the reverted "r" mode, give the same reverted tones on the wsjt window, and no decode, of course. Is JT65 impossible on this mode, or do I have to reconsider the filters alignment or anything else ? Best 72 de Jean-Marc, F5LCI "To nobody, except those who will take pleasure here" (Franz Schubert, 1797-1828) |
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Jean-Marc,
Yes, you will need to align those filters. I normally set the FL1 position to OP1, FL2 to 1.00, FL3 to 0.70 and FL4 to 0.40 widths. Then set the BFOs for FL1 to the same values as the SSB filters - RTTY corresponds to LSB and RTTY REV corresponds to USB. That filter will be used for transmit in all cases and works well with a waterfall display for normal receive. Set the other filters to center on 1000 Hz. Those can be used if a strong interfering signal appears inside the passband of the OP1 filter. Observe the LSB/USB relationship - the DAC numbers (and also frequency) will be higher for RTTY REV. If you have the KDSP2 option, also set those filters 2, 3, and 4 to center at 1000 Hz to agree with the IF filter centers. The use of Spectrogram is recommended when aligning the IF filters. You can download a copy from my website www.w3fpr.com - look near the bottom of the home page. Instructions for the use of Spectrogram can be found in the K2 Dial Calibration article. 73, Don W3FPR On 2/11/2014 3:07 AM, F5LCI wrote: > Hello, > After successful use of JT65 with my KX3 overseas, I am back to my K2. > According to the manual, the "r" mode is advised, because passband and ALC > are optimized. > (I never use RTTY) > On my rig, the "r" mode, as the reverted "r" mode, give the same reverted > tones on the wsjt window, and no decode, of course. > Is JT65 impossible on this mode, or do I have to reconsider the filters > alignment or anything else ? > > Best 72 de Jean-Marc, F5LCI > > "To nobody, except those who will take pleasure here" (Franz Schubert, > 1797-1828) > > > > -- > View this message in context: http://elecraft.365791.n2.nabble.com/JT-modes-alignment-tp7584041.html > Sent from the Elecraft 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:[hidden email] > > 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:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
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Hi Don, and thank you for the fast reply (as usual!)
I can use the USB mode, decoding is OK, But the ALC is not optimized for digital modes. My only problem: "R" and reverse "R" behave equally ; I thought that the tones would be inverted... I seriously wonder : Was I wrong with alignment with the reverse "R" mode only ? I had carefully aligned my filters ...many years ago, before JT65 appeared. So I'll have to RTFM to remind the procedure. Back to the book... 72, Jean-Marc, F5LCI Le Tue, 11 Feb 2014 14:15:27 +0100, Don Wilhelm <w3fpr@embarqmail.com> a écrit: > Jean-Marc, > > Yes, you will need to align those filters. > I normally set the FL1 position to OP1, FL2 to 1.00, FL3 to 0.70 and FL4 > to 0.40 widths. > Then set the BFOs for FL1 to the same values as the SSB filters - RTTY > corresponds to LSB and RTTY REV corresponds to USB. That filter will be > used for transmit in all cases and works well with a waterfall display > for normal receive. > Set the other filters to center on 1000 Hz. Those can be used if a > strong interfering signal appears inside the passband of the OP1 > filter. Observe the LSB/USB relationship - the DAC numbers (and also > frequency) will be higher for RTTY REV. > > If you have the KDSP2 option, also set those filters 2, 3, and 4 to > center at 1000 Hz to agree with the IF filter centers. > > The use of Spectrogram is recommended when aligning the IF filters. You > can download a copy from my website www.w3fpr.com - look near the bottom > of the home page. Instructions for the use of Spectrogram can be found > in the K2 Dial Calibration article. > > 73, > Don W3FPR |
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Jean-Marc,
As I indicated, RTTY FL1 should be set to the OP1 filter and copy the BFO setting from the LSB BFO. Likewise copy the RTTY REV BFO setting from the SSB USB BFO and you should have the RTTY FL1 behave just like USB or LSB with the exception that there is an independent SSBC setting (look for SSBCr) in the menu - it should be set to no compression (1-1) for digital modes. As far as I know, the ALC will be the same as for SSB, but one usually adds compression for SSB use which will make the ALC more aggressive. As with all digital modes with the K2, adjust the audio level so you can see just one bar of ALC indication, then back the audio down until that indicator just goes off. Adjust the desired power level with the POWER knob. Yes, this is different than the 'conventional wisdom' you will see in instructions for other rigs that control power differently than the K2. 73, Don W3FPR On 2/11/2014 9:38 AM, F5LCI wrote: > Hi Don, and thank you for the fast reply (as usual!) > I can use the USB mode, decoding is OK, But the ALC is not optimized for > digital modes. > > My only problem: "R" and reverse "R" behave equally ; I thought that the > tones would be inverted... > I seriously wonder : Was I wrong with alignment with the reverse "R" mode > only ? > I had carefully aligned my filters ...many years ago, before JT65 appeared. > So I'll have to RTFM to remind the procedure. > Back to the book... > > 72, Jean-Marc, F5LCI > > > Le Tue, 11 Feb 2014 14:15:27 +0100, Don Wilhelm <[hidden email]> a > écrit: > >> Jean-Marc, >> >> Yes, you will need to align those filters. >> I normally set the FL1 position to OP1, FL2 to 1.00, FL3 to 0.70 and FL4 >> to 0.40 widths. >> Then set the BFOs for FL1 to the same values as the SSB filters - RTTY >> corresponds to LSB and RTTY REV corresponds to USB. That filter will be >> used for transmit in all cases and works well with a waterfall display >> for normal receive. >> Set the other filters to center on 1000 Hz. Those can be used if a >> strong interfering signal appears inside the passband of the OP1 >> filter. Observe the LSB/USB relationship - the DAC numbers (and also >> frequency) will be higher for RTTY REV. >> >> If you have the KDSP2 option, also set those filters 2, 3, and 4 to >> center at 1000 Hz to agree with the IF filter centers. >> >> The use of Spectrogram is recommended when aligning the IF filters. You >> can download a copy from my website www.w3fpr.com - look near the bottom >> of the home page. Instructions for the use of Spectrogram can be found >> in the K2 Dial Calibration article. >> >> 73, >> Don W3FPR > > > -- > View this message in context: http://elecraft.365791.n2.nabble.com/JT-modes-alignment-tp7584041p7584044.html > Sent from the Elecraft 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:[hidden email] > > 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:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
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