Tips on setting transmit drive for PSK31
Locked
Tips on setting transmit drive for PSK31
 
|
I'm trying to get my K3 running on PSK31. Everything seems fine so
far. I'm using line in/line out into mic and headphone on my laptop. Copy is very good. Transmit drive is touchy and I'm wondering if anyone has any tips on setting the correct amount of audio drive. My power is set to 20 watts, compression off. Audio gain is 6. Transmit gives me about 10 watts or so. Should I increase gain until I get 20 watts? Thanks for any input, Doug -- K0DXV PS: UPS just handed me another white box. Its my third K2 and its number 6798. Time to warm up the iron. ______________________________________________________________ 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 |
|
|
> I'm trying to get my K3 running on PSK31. Everything seems fine so > far. I'm using line in/line out into mic and headphone on my laptop. > Copy is very good. Transmit drive is touchy and I'm wondering if anyone > has any tips on setting the correct amount of audio drive. 4 bars of ALC flickering to 5. 73, Lyle KK7P ______________________________________________________________ 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 |
Re: Tips on setting transmit drive for PSK31
|
|
In reply to this post by Doug Person
Doug,
Do not use the power output as an indication for mic drive on data modes (PSK31 for example). The proper indicator is the "ALC" bargraph - adjust the audio input for 4 bars with an occasional flicker of the 5th bar. At that level, it is not an indication of ALC action nor compression. The ALC does not start until the 5th or 6th bar is illuminated - the lower 4 bars are an indicator of the audio level (sort of like a Vu meter). If you set the audio drive too low, the K3 will attempt to develop more power to maintain the power output level you have chosen - that is the reason things seem so 'touchy'. 73, Don W3FPR Doug Person wrote: > I'm trying to get my K3 running on PSK31. Everything seems fine so > far. I'm using line in/line out into mic and headphone on my laptop. > Copy is very good. Transmit drive is touchy and I'm wondering if anyone > has any tips on setting the correct amount of audio drive. My power is > set to 20 watts, compression off. Audio gain is 6. Transmit gives me > about 10 watts or so. Should I increase gain until I get 20 watts? > > Thanks for any input, > > Doug -- K0DXV > > PS: UPS just handed me another white box. Its my third K2 and its > number 6798. Time to warm up the iron. > ______________________________________________________________ > 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 > ------------------------------------------------------------------------ > > > No virus found in this incoming message. > Checked by AVG - www.avg.com > Version: 8.5.409 / Virus Database: 270.13.76/2343 - Release Date: 09/03/09 05:50:00 > > 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 |
|
|
--- On Thu, 9/3/09, Don Wilhelm <[hidden email]> wrote: From: Don Wilhelm <[hidden email]> Subject: Re: [Elecraft] Tips on setting transmit drive for PSK31 To: "Doug Person" <[hidden email]> Cc: "[hidden email]" <[hidden email]> Date: Thursday, September 3, 2009, 4:06 PM Doug, Do not use the power output as an indication for mic drive on data modes (PSK31 for example). The proper indicator is the "ALC" bargraph - adjust the audio input for 4 bars with an occasional flicker of the 5th bar. At that level, it is not an indication of ALC action nor compression. The ALC does not start until the 5th or 6th bar is illuminated - the lower 4 bars are an indicator of the audio level (sort of like a Vu meter). If you set the audio drive too low, the K3 will attempt to develop more power to maintain the power output level you have chosen - that is the reason things seem so 'touchy'. 73, Don W3FPR Don, I'm curious about your statement that "the K3 will attempt to develop more power to maintain the power output level you have chosen" - Since PSK is an audio driven mode with a varying amplitude component, linearity is very important. What you are suggesting is that the K3 is highly non-linear and has infinite gain, i.e. it puts out X watts regardless of drive. I know that you don't mean that, so could you clarify? Wes N7WS ______________________________________________________________ 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 |
Re: Tips on setting transmit drive for PSK31
|
|
Wes,
The capability operates within limits - it cannot be infinite. However, the K3 (K2 as well) uses a control loop for power output control. It senses the output power and adjusts the RF drive to compensate for differences in the power requested and the actual. In SSB (and data modes) it operates on the peak values, so it will be related to the peak audio level rather than to the average. The K2 has operated this way all its life, but the K3 has a more sophisticated detection mechanism, so control can be more precise than the K2. It still takes a bit of output time for the power to settle down, and that fact has caused a bit of 'wonderment' among users - if the response is too fast, the power level will oscillate because of the required high gain in the control loop, so it take a couple dit times (or equal for SSB and Data modes) for the power to level out. The control loop is reset with a band change, and a few other actions that I cannot recall right now. 73, Don W3FPR Wes Stewart wrote: > > Don, > > I'm curious about your statement that "the K3 will attempt to develop more power to maintain the power output level you have chosen" - > > Since PSK is an audio driven mode with a varying amplitude component, linearity is very important. What you are suggesting is that the K3 is highly non-linear and has infinite gain, i.e. it puts out X watts regardless of drive. > > I know that you don't mean that, so could you clarify? > > Wes N7WS > > 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 |
Re: Tips on setting transmit drive for PSK31
|
|
In reply to this post by n7ws
A while back this was addressed by Lyle in this post:
http://n2.nabble.com/K3-Transmit-IMD-tp466326p466329.html Whether or not it remains current I can't say. Bob NW8L > > I'm curious about your statement that "the K3 will attempt to develop more power to maintain the power output level you have chosen" - > > Since PSK is an audio driven mode with a varying amplitude component, linearity is very important. What you are suggesting is that the K3 is highly non-linear and has infinite gain, i.e. it puts out X watts regardless of drive. > > I know that you don't mean that, so could you clarify? > > Wes N7WS ______________________________________________________________ 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 |
|
|
> A while back this was addressed by Lyle in this post: > > http://n2.nabble.com/K3-Transmit-IMD-tp466326p466329.html > > Whether or not it remains current I can't say. > Lyle thinks it is still true with the latest code - I just checked! 73, Lyle KK7P ______________________________________________________________ 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 |
|
|
In reply to this post by Bob Cunnings NW8L
Hello, I am also just testing PSK on K3 with Microham keyer using Data A mode and get different results.. Fist think is if you proper adjust level from sound card that ALC meter show 4 bars and 5 flickering on 1500Hz means that every time when you change listen channel needs to re-adjust Mic gain to get good ALC level.. So, if you on highest freq. you will overdrive K3 but if you goes little down maybe you can not drive correctly K3 for require power... Please your opinion! 73, e72x - Gordan --- On Fri, 9/4/09, Bob Cunnings <[hidden email]> wrote: From: Bob Cunnings <[hidden email]> Subject: Re: [Elecraft] Tips on setting transmit drive for PSK31 To: [hidden email] Date: Friday, September 4, 2009, 6:20 AM A while back this was addressed by Lyle in this post: http://n2.nabble.com/K3-Transmit-IMD-tp466326p466329.html Whether or not it remains current I can't say. Bob NW8L > > I'm curious about your statement that "the K3 will attempt to develop more power to maintain the power output level you have chosen" - > > Since PSK is an audio driven mode with a varying amplitude component, linearity is very important. What you are suggesting is that the K3 is highly non-linear and has infinite gain, i.e. it puts out X watts regardless of drive. > > I know that you don't mean that, so could you clarify? > > Wes N7WS ______________________________________________________________ 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 |
Re: Tips on setting transmit drive for PSK31
|
|
> I am also just testing PSK on K3 with Microham keyer using > Data A mode and get different results.. Fist think is if you > proper adjust level from sound card that ALC meter show 4 > bars and 5 flickering on 1500Hz means that every time when > you change listen channel needs to re-adjust Mic gain to get > good ALC level.. Do you have the TX EQ set to anything except flat? There should be no change in output level with audio frequency with any of the microHAM interfaces. 73, ... Joe, W4TV > -----Original Message----- > From: [hidden email] > [mailto:[hidden email]] On Behalf Of Gordan Hribar > Sent: Friday, September 04, 2009 4:36 AM > To: [hidden email] > Subject: Re: [Elecraft] Tips on setting transmit drive for PSK31 > > > > Hello, > > I am also just testing PSK on K3 with Microham keyer using > Data A mode and get different results.. Fist think is if you > proper adjust level from sound card that ALC meter show 4 > bars and 5 flickering on 1500Hz means that every time when > you change listen channel needs to re-adjust Mic gain to get > good ALC level.. So, if you on highest freq. you will > overdrive K3 but if you goes little down maybe you can not > drive correctly K3 for require power... > Please your opinion! > > 73, > e72x - Gordan > > --- On Fri, 9/4/09, Bob Cunnings <[hidden email]> wrote: > > > From: Bob Cunnings <[hidden email]> > Subject: Re: [Elecraft] Tips on setting transmit drive for PSK31 > To: [hidden email] > Date: Friday, September 4, 2009, 6:20 AM > > > A while back this was addressed by Lyle in this post: > > http://n2.nabble.com/K3-Transmit-IMD-tp466326p466329.html > > Whether or not it remains current I can't say. > > Bob NW8L > > > > > I'm curious about your statement that "the K3 will attempt > to develop > > more power to maintain the power output level you have chosen" - > > > > Since PSK is an audio driven mode with a varying amplitude > component, > > linearity is very important. What you are suggesting is > that the K3 > > is highly non-linear and has infinite gain, i.e. it puts > out X watts > > regardless of drive. > > > > I know that you don't mean that, so could you clarify? > > > > Wes N7WS > ______________________________________________________________ > 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 ______________________________________________________________ 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 |
|
|
In reply to this post by Don Wilhelm-4
I notice that there is a slight power output variation between the two FSK
tones (as seen on an external meter, there isn't enough resolution on the K3's meter to see it). Is this a result of filter ripple or is something else at work here? (since not AFSK not EQ or sound card settings). Mark n2qt ______________________________________________________________ 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 |
|
|
In reply to this post by Doug Person
Don,
Can this approach be used with the K2 in digital modes and if so what are the suggested settings for the 'bars' when the ALC is turned on? 73, Nigel ZL2DF Snip The K2 has operated this way all its life, but the K3 has a more sophisticated detection mechanism, so control can be more precise than the K2. It still takes a bit of output time for the power to settle down, and that fact has caused a bit of 'wonderment' among users - if the response is too fast, the power level will oscillate because of the required high gain in the control loop, so it take a couple dit times (or equal for SSB and Data modes) for the power to level out. The control loop is reset with a band change, and a few other actions that I cannot recall right now. 73, Don W3FPR ______________________________________________________________ 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 |
Re: Tips on setting transmit drive for PSK31
|
|
Nigel,
Yes, a similar procedure can be used with the K2. The K2 ALC indication does indicate actual ALC, so the best setting for the K2 is to increase the audio until you see a flicker on the ALC meter and then back off slightly until it disappears. Because there is no MCU compensation for band to band TX gain variations in the K2, you will likely find the proper setting will change from band to band. Unlike the K3, the K2 has no internal "fancy code" for data modes other than the addition of the RTTY filter set because PSK31 was not popular when the K2 was first designed. BTW - Do use the RTTY filter set for data modes on the K2 rather than SSB mode mainly because it gives you an independent compression setting (which should be 1:1). I set RTTY FL1 the same as SSB FL1 (the OP1 filter must be used for transmit), and then I set FL2= 1.00, FL3=0.70 and FL4=0.40 and center FL2 through FL4 at 1000 Hz. I tune the desired signal near 1000 Hz on the waterfall andin that way I am prepared to narrow the filter if QRM creeps in. The RTTY center frequencies must also be changed to 1000 Hz if the DSP filters are to be used in conjunction with the IF filters. 73, Don W3FPR Nigel wrote: > Don, > Can this approach be used with the K2 in digital modes and if so what are > the suggested settings for the 'bars' when the ALC is turned on? > > 73, Nigel ZL2DF > > > Snip > The K2 has operated this way all its life, but the K3 has a more > sophisticated detection mechanism, so control can be more precise than > the K2. It still takes a bit of output time for the power to settle > down, and that fact has caused a bit of 'wonderment' among users - if > the response is too fast, the power level will oscillate because of the > required high gain in the control loop, so it take a couple dit times > (or equal for SSB and Data modes) for the power to level out. The > control loop is reset with a band change, and a few other actions that I > cannot recall right now. > > 73, > Don W3FPR > > > > > > ______________________________________________________________ > 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 > ------------------------------------------------------------------------ > > > No virus found in this incoming message. > Checked by AVG - www.avg.com > Version: 8.5.409 / Virus Database: 270.13.76/2345 - Release Date: 09/04/09 05:51:00 > > 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 |
«
Return to [K3]
|
1 view|%1 views
| Free forum by Nabble | Edit this page |