K3 Beta firmware rev. 2.80: Improvements to AFSK-A, DATA-A, SSB, AM, FM, DVR
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K3 Beta firmware rev. 2.80: Improvements to AFSK-A, DATA-A, SSB, AM, FM, DVR
 
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K3 beta-test firmware revision 2.82 (with DSP rev 2.00) is now
available. See release notes below. Please send any problem reports to [hidden email]. For instructions on how to load beta firmware, please see: http://www.elecraft.com/K3/k3_software.htm We also recommend that you use the latest revision of K3 Utility, which can also be found on this page. 73, Wayne N6KR * * * MCU 2.82 / DSP 2.00, 2-9-2009 Data Mode Changes: * AFSK MODE TRANSMIT FILTERING: Some K3 owners have reported hearing noise on their RTTY transmit signal when using AFSK-A mode. Possible sources of noise include RFI, ground loops, low AF level, or poor mark/space transition shaping by software. The effects of noise from many sources can be eliminated by using a narrow, constant-delay transmit filter (DSP). To enable this filter, set CONFIG:AFSK TX, to FIL ON (default is OFF). * SSB/DATA-A/AFSK-A TRANSMIT POWER LEVEL: Power output in these modes now more closely tracks TUNE power. We recommend setting CONFIG:TXG VCE to 0.0 dB after loading this release, then adjusting only if necessary. * DATA MODE ALC METERING: ALC metering for DATA-A and AFSK-A modes has been adjusted to make the transmit audio level easier to adjust. As before, the recommended audio level for transmission is 4 to 5 bars. 3 bars will appear as soon the minimum required level for good S/N ratio has been reached. * FSK POLARITY MENU ENTRY: Setting CONFIG:FSK POL to 0 reverses RTTY data polarity (applies only to FSK-D mode transmit) . Note: If you use the ALT switch to select DATA REV mode, this reverses both RX and TX tones, in both AFSK-A and FSK-D modes. This should rarely be required. FSK POL can be used by itself or in combination with DATA REV. Misc. Changes: * DVR MESSAGE CANCEL WITH PTT OR VOX: Both one-time and repeating DVR transmit message play can now be cancelled cleanly with either PTT or VOX. * AM MODE SPEECH COMPRESSION: Speech compression is now available in AM mode. This can add punch to your AM signal. As with any type of compression, it should be used only when necessary. * FM TX DEVIATION: This is now more accurate. Previous versions could underdeviate by as much as 1 kHz. Setting is now accurate from 3.0 kHz to 5.0 kHz of deviation when modulated by 1 kHz tone with 5 bars of ALC indicated. For software developers: * “BN” COMMAND ADDED (Band Number). GET only. This command returns the K3’s present band number (0-10 = 160 m - 6 m, 11-15 reserved for future use, 16-24 = XVTR bands 1-9). It is useful for software applications that need to know if the operator has tuned the VFO across a logical band boundary. This eliminates the need for applications to keep track of what the K3’s internal band boundaries are. --- http://www.elecraft.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 |
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In a recent message, wayne burdick <[hidden email]> wrote ...
> >K3 beta-test firmware revision 2.82 (with DSP rev 2.00) is now >available. See release notes below. Many thanks for the latest firmware - all installed successfully and apparently working okay. In a future release, would it be possible for the Power Level RF indicator to show the mW power when using the K3 with the XV--- transverters? While accepting the limitations of the LCD display, it would be useful if the power meter read from 0 to 1.2mW. 73 -- David G4DMP Leeds, England, UK ------ ______________________________________________________________ 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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In reply to this post by wayne burdick
hi Wayne,
wayne burdick schrieb am 10 Feb 2009 um 15:00: > * SSB/DATA-A/AFSK-A TRANSMIT POWER LEVEL: Power output in these > modes now more closely tracks TUNE power. We recommend setting > CONFIG:TXG VCE to 0.0 dB after loading this release, then adjusting only if > necessary. > > * DATA MODE ALC METERING: ALC metering for DATA-A and AFSK-A > modes has been adjusted to make the transmit audio level easier to > adjust. > As before, the recommended audio level for transmission is 4 to 5 bars. 3 > bars will appear as soon the minimum required level for good S/N ratio has > been reached. I tested the new firmware with my K3 + Ptc-2 TRX modem built inside the K3 and I think you have made a good improvement with the latest firmware 2.82. The output measured on my LP-100 meter is in a 5% range close to the power setting of the K3. I had to set the LINE IN GAIN higher than before, it is now at 20, before it was at 12. My output settings in the TRX-PTC modem are set to 1000mV for PSKA and 800 mV for FSKA. TXG VCE is set to 0.0dB This combination gives me the recommanded 4 bars of ALC. Throughput is good as far I can tell - I'll have to check this in the evening with better conditions to the RMS oe3xec which I can connect on 80m in distance of 280 nautical miles. thank you very much, that's what I like with you and the K3. It's getting better every time ;-) 73! de Werner OE9FWV -- "Was ist ein Zyniker? Ein Mann, der von allem den Preis und von nichts den Wert kennt." Oscar Wilde Email powered by Pegasus Mail free at <http://www.pmail.com> Homepage: <http://www.qsl.net/oe9fwv/> Fone +43 5522 75013 Fax +43 5522 75013 15 Mobile +43 664 6340014 Elecraft K2 #5203 K3 #656 ______________________________________________________________ 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: K3 Beta firmware rev. 2.82
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In reply to this post by David Pratt
I installed the new beta last and tested the new output power control. I don't see any improvement in PSK31 output power using DATA A mode. I still get nearly twice the output power than I have dialed in by the PWR knob. In the previous firmware, the measure output power in CW modes agreed with the PWR knob setting, but now the power output in CW is 20-30% higher than the setting. I will try to redo the transmitter gain calibration to see if this helps. Steve N9SZ K3 #1672 ______________________________________________________________ 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 Steve,
Seems to work correctly here even if I exceed the recommended 5 bars of ALC. 73 Doug N3QW ----- Original Message ----- From: <[hidden email]> To: <[hidden email]> Sent: Wednesday, February 11, 2009 9:16 AM Subject: Re: [Elecraft] K3 Beta firmware rev. 2.82 > > I installed the new beta last and tested the new output power control. I > don't see any improvement in PSK31 output power using DATA A mode. I still > get nearly twice the output power than I have dialed in by the PWR knob. > In > the previous firmware, the measure output power in CW modes agreed with > the > PWR knob setting, but now the power output in CW is 20-30% higher than the > setting. > > I will try to redo the transmitter gain calibration to see if this helps. > > Steve N9SZ > K3 #1672 > > ______________________________________________________________ > 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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In reply to this post by Steven.Zabarnick
On Wed, 11 Feb 2009 09:16:45 -0500, you wrote:
> >I installed the new beta last and tested the new output power control. I >don't see any improvement in PSK31 output power using DATA A mode. I still >get nearly twice the output power than I have dialed in by the PWR knob. In >the previous firmware, the measure output power in CW modes agreed with the >PWR knob setting, but now the power output in CW is 20-30% higher than the >setting. > >I will try to redo the transmitter gain calibration to see if this helps. > >Steve N9SZ >K3 #1672 I too installed the 1.82 last night. I have no power output problems after making the install, but then, I didn't have any to begin with. Tom, N5GE http://www.n5ge.com http://www.swotrc.net K3 #806 XV144 XV432 ______________________________________________________________ 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
Amateur Radio Operator N5GE
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In reply to this post by Steven.Zabarnick
I don't see a problem with CW on my K3 (29.4W measured, 30W
requested,) but there are definitely still problems with excessive power output in DATA-A. DATA-A initially output the correct power, but after switching to AFSK-A and back to DATA-A, I get well over 2x the requested power out (71W measured vs 30W requested.) 73 -- Joe KB8AP On Feb 11, 2009, at 6:16 AM, [hidden email] wrote: > > I installed the new beta last and tested the new output power > control. I > don't see any improvement in PSK31 output power using DATA A mode. I > still > get nearly twice the output power than I have dialed in by the PWR > knob. In > the previous firmware, the measure output power in CW modes agreed > with the > PWR knob setting, but now the power output in CW is 20-30% higher > than the > setting. > > I will try to redo the transmitter gain calibration to see if this > helps. > > Steve N9SZ > K3 #1672 > > ______________________________________________________________ > 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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In reply to this post by Steven.Zabarnick
I have just got round to testing this firmware release. Before testing the power output in DATA A mode I did a power calibration. It seems to me that there is still something wrong with the power control in DATA A mode. To make a comparison, I switched the input for SSB to LINE IN so I could compare the power output when sending a pure tone in both modes. In DATA A the gain seems to have been reduced, and I had to increase the LINE IN setting. With PWR set to 50W and the input level set to give a steady 4 bars, I measured 80W on my power meter. A slight improvement but still not enough. In SSB the power output was correctly controlled so that only 50W output was produced. However, after switching between SSB and DATA a few times to compare the results, and also changing bands, I found that the output in DATA is not consistent. Currently I am getting about 65W for 50 selected. At one point on 20m I actually got 50W. On 30m I am actually getting 20W (yes, 20W) with 50W selected, absolutely no change to the audio input compared to the other bands, and 4 bars of ALC showing. Back to the drawing board?
Julian, G4ILO. K2 #392 K3 #222 KX3 #110
* G4ILO's Shack - http://www.g4ilo.com * KComm - http://www.g4ilo.com/kcomm.html * KTune - http://www.g4ilo.com/ktune.html |
Re: K3 Beta firmware rev. 2.82
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In reply to this post by David Pratt
I discovered that my cw power issue was due to a bad power supply for my
Elecraft W1 wattmeter. My cw power measurement now agrees with the K3 setting. I still see a 50% higher power output in Data A mode than the K3 setting -- this is an improvement over the nearly 100% that I was seeing using previous firmware. These observations agree with what G4ILO is seeing. > >I installed the new beta last and tested the new output power control. >I don't see any improvement in PSK31 output power using DATA A mode. I >still get nearly twice the output power than I have dialed in by the >PWR knob. In the previous firmware, the measure output power in CW >modes agreed with the PWR knob setting, but now the power output in CW >is 20-30% higher than the setting. > > >I will try to redo the transmitter gain calibration to see if this >helps. > >Steve N9SZ > >K3 #1672 ______________________________________________________________ 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: K3 Beta firmware rev. 2.82
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In reply to this post by Julian, G4ILO
You CAN NOT make those tests at 50 Watts! The power calibration circuitry will be constantly changing the internal gain. If the ATU is enabled and/or your dummy load is not flat the changes invalidate the measurements. Further, single tone power calibration is only accurate for the specific frequency within the IF filter on which the calibration is performed. If I calibrate power in CW mode that calibration point is approximately 300 Hz from one "corner" of the 2.8 KHz filter thanks to the way the K3 offsets the filters. When I switch to DATA A, and try to test the power level with a 1500 Hz tone, I can see 2 dB more power simply because my 2.8 KHz filter has a 4 dB slope across the passband and the K3 gain calculation includes compensation for the loss at the calibration frequency. If I check the power with a 1 KHz tone, the difference may be 3 dB (DATA A is USB, CW calibration is LSB so the slope changes direction with tone). If I switch to AFSK A (REV to stay with USB) and check power with a 2295 Hz (USB Mark) tone, the difference may be down to one dB or so. There are too many uncompensated variables to expect the K3 to maintain absolute control over the power output with changing antennas, power levels, modes, (relative) frequency within the IF passband and possibly even different filters. ALC controls the audio level into, and the RF level out of the DSP (modulator) process - it is an ALC (automatic LEVEL control) NOT an APC (automatic POWER control). The ALC is an open loop system - the loop gain is calibrated once at the 5 watt level and once at the 50 watt level for one specific frequency in the IF passband. Once that is done, ALC simply controls the DSP gain. If you change the system gain following the DSP, the output power level WILL CHANGE. I'm sure it would be theoretically possible to calibrate the system gain from 100 Hz to 2900 Hz offsets from the carrier (for both the USB and LSB cases) and apply that mask to the modulation process but does the DSP system have enough horsepower to do so and is it worthwhile simply so the operator can avoid the need to check his power level when changing mode or modulating frequency? 73, ... Joe, W4TV > -----Original Message----- > From: [hidden email] > [mailto:[hidden email]] On Behalf Of Julian, G4ILO > Sent: Saturday, February 14, 2009 11:58 AM > To: [hidden email] > Subject: Re: [Elecraft] K3 Beta firmware rev. 2.82 > > > > > Steven.Zabarnick wrote: > > > > > > I installed the new beta last and tested the new output > power control. > > I don't see any improvement in PSK31 output power using > DATA A mode. I > > still get nearly twice the output power than I have dialed > in by the > > PWR knob. In the previous firmware, the measure output power in CW > > modes agreed with the > > PWR knob setting, but now the power output in CW is 20-30% > higher than the > > setting. > > > > I will try to redo the transmitter gain calibration to see if this > > helps. > > > > > I have just got round to testing this firmware release. > Before testing the power output in DATA A mode I did a power > calibration. > > It seems to me that there is still something wrong with the > power control in DATA A mode. To make a comparison, I > switched the input for SSB to LINE IN so I could compare the > power output when sending a pure tone in both modes. > > In DATA A the gain seems to have been reduced, and I had to > increase the LINE IN setting. With PWR set to 50W and the > input level set to give a steady 4 bars, I measured 80W on my > power meter. A slight improvement but still not enough. > > In SSB the power output was correctly controlled so that only > 50W output was produced. > > However, after switching between SSB and DATA a few times to > compare the results, and also changing bands, I found that > the output in DATA is not consistent. Currently I am getting > about 65W for 50 selected. At one point on 20m I actually got > 50W. On 30m I am actually getting 20W (yes, 20W) with 50W > selected, absolutely no change to the audio input compared to > the other bands, and 4 bars of ALC showing. > > Back to the drawing board? > > ----- > Julian, G4ILO. K2 #392 K3 #222. > http://www.g4ilo.com/ G4ILO's Shack > http://www.g4ilo.com/blog.html G4ILO's > Blog http://www.g4ilo.com/kcomm.html KComm for Elecraft K2 and K3 > -- > View this message in context: > http://n2.nabble.com/K3-Beta-firmware-rev.-2.80%3A-Improvement 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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Why on earth not? I think you are confusing the situation with what happens when you press TUNE at 50 watts (which I personally think is a disaster that has already happened on many occasions, but that is another matter.) If you are suggesting that you cannot use the K3 AT ALL with the power set to 50 watts then something is deeply wrong, either with your understanding or with the design of the radio. Well I may not be a professional radio engineer but I am not dumb enough to try testing with different frequency tones. As stated, I was testing with the same tone in SSB and DATA mode. As far as I am aware, the filter passband on transmit is the same in both modes. Even if not, this does not explain why I got 65W on most bands and 20W on 30m, with exactly the same input. Sorry, but I don't see where the system gain comes in to the argument, since I am reporting results with the same frequency tone used at all times. Nor do I see why changing antennas has any relevance to this issue, since I am using a dummy load that is flat to 500MHz for these tests. The K3 is perfectly capable of regulating the power to a level of accuracy that is acceptable to me in SSB mode. All I am asking is that it perform the same task in DATA A, which is just SSB after all. Early versions of the firmware were perfectly capable of doing this. Why am I being treated as if I am demanding the impossible for simply asking for something that can be done and has been done. I really am very, very fed up with the K3 at this point in time.
Julian, G4ILO. K2 #392 K3 #222 KX3 #110
* G4ILO's Shack - http://www.g4ilo.com * KComm - http://www.g4ilo.com/kcomm.html * KTune - http://www.g4ilo.com/ktune.html |
Re: K3 Beta firmware rev. 2.82
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> Why on earth not? I think you are confusing the situation > with what happens when you press TUNE at 50 watts (which I > personally think is a disaster that has already happened > on many occasions, but that is another matter.) To normalize the radio's output power for any valid test you need to measure the single tone carrier power (e.g., CW). If you do that (press tune at 50 watts), you will recalibrate. The recalibration will render any subsequent measurement incompatible with previous measurements. > If you are suggesting that you cannot use the K3 AT ALL with > the power set to 5o watts then something is deeply wrong, > either with your understanding or with the design of the > radio. That's not what I'm suggesting at all. I'm saying you can't make repeatable measurements at 50.0 watts because of the need to calibrate the power level before undertaking measurements. Make the measurements at 40 or 60 watts to eliminate the errors introduced by automatic recalibration. As to understanding of the radio ... anyone who thinks the ALC should act as an APC has a far distance to go in their understanding of the radio and those factors that impact power output. > -----Original Message----- > From: [hidden email] > [mailto:[hidden email]] On Behalf Of Julian, G4ILO > Sent: Saturday, February 14, 2009 3:44 PM > To: [hidden email] > Subject: Re: [Elecraft] K3 Beta firmware rev. 2.82 > > > > > Joe Subich, W4TV-4 wrote: > > > > > > You CAN NOT make those tests at 50 Watts! The power calibration > > circuitry will be constantly changing the internal gain. If > > the ATU is enabled and/or your dummy load is not flat the changes > > invalidate the measurements. > > > > Why on earth not? I think you are confusing the situation > with what happens > when you press TUNE at 50 watts (which I personally think is > a disaster that > has already happened on many occasions, but that is another > matter.) If you > are suggesting that you cannot use the K3 AT ALL with the > power set to 50 > watts then something is deeply wrong, either with your > understanding or with > the design of the radio. > > > > > > > Further, single tone power calibration is only accurate for > > the specific frequency within the IF filter on which the > > calibration is performed. If I calibrate power in CW mode > > that calibration point is approximately 300 Hz from one > > "corner" of the 2.8 KHz filter thanks to the way the K3 > > offsets the filters. When I switch to DATA A, and try to > > test the power level with a 1500 Hz tone, I can see 2 dB more > > power simply because my 2.8 KHz filter has a 4 dB slope across > > the passband and the K3 gain calculation includes compensation > > for the loss at the calibration frequency. If I check the > > power with a 1 KHz tone, the difference may be 3 dB (DATA A > > is USB, CW calibration is LSB so the slope changes direction > > with tone). If I switch to AFSK A (REV to stay with USB) > > and check power with a 2295 Hz (USB Mark) tone, the difference > > may be down to one dB or so. > > > > Well I may not be a professional radio engineer but I am not > dumb enough to > try testing with different frequency tones. As stated, I was > testing with > the same tone in SSB and DATA mode. As far as I am aware, the filter > passband on transmit is the same in both modes. Even if not, > this does not > explain why I got 65W on most bands and 20W on 30m, with > exactly the same > input. > > > > > > > There are too many uncompensated variables to expect the K3 > > to maintain absolute control over the power output with > > changing antennas, power levels, modes, (relative) frequency > > within the IF passband and possibly even different filters. > > ALC controls the audio level into, and the RF level out of > > the DSP (modulator) process - it is an ALC (automatic LEVEL > > control) NOT an APC (automatic POWER control). > > > > The ALC is an open loop system - the loop gain is calibrated > > once at the 5 watt level and once at the 50 watt level for > > one specific frequency in the IF passband. Once that is > > done, ALC simply controls the DSP gain. If you change the > > system gain following the DSP, the output power level WILL > > CHANGE. I'm sure it would be theoretically possible to > > calibrate the system gain from 100 Hz to 2900 Hz offsets > > from the carrier (for both the USB and LSB cases) and apply > > that mask to the modulation process but does the DSP system > > have enough horsepower to do so and is it worthwhile simply > > so the operator can avoid the need to check his power level > > when changing mode or modulating frequency? > > > > > > Sorry, but I don't see where the system gain comes in to the > argument, since > I am reporting results with the same frequency tone used at > all times. Nor > do I see why changing antennas has any relevance to this > issue, since I am > using a dummy load that is flat to 500MHz for these tests. > > The K3 is perfectly capable of regulating the power to a > level of accuracy > that is acceptable to me in SSB mode. All I am asking is that > it perform the > same task in DATA A, which is just SSB after all. Early > versions of the > firmware were perfectly capable of doing this. Why am I being > treated as if > I am demanding the impossible for simply asking for something > that can be > done and has been done. > > I really am very, very fed up with the K3 at this point in time. > > ----- > Julian, G4ILO. K2 #392 K3 #222. > http://www.g4ilo.com/ G4ILO's Shack > http://www.g4ilo.com/blog.html G4ILO's > Blog http://www.g4ilo.com/kcomm.html KComm for Elecraft K2 and K3 > -- > View this message in context: > http://n2.nabble.com/K3-Beta-firmware-rev.-2.80%3A-Improvement 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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In reply to this post by Joe Subich, W4TV-4
Hi Joe,
> Further, single tone power calibration is only accurate for > the specific frequency within the IF filter on which the > calibration is performed. If I calibrate power in CW mode > that calibration point is approximately 300 Hz from one > "corner" of the 2.8 KHz filter thanks to the way the K3 > offsets the filters. If I understand you correctly, you're essentially saying that in DATA- A (where, according to Elecraft, ALC action is intentionally minimized to minimize distortion), we're seeing more of the true shape of the filter passband. Whereas in a voice mode (USB or LSB, where ALC action is more pronounced,) the ALC action will tend to make the filter passband appear flat if the input is a single tone. To test this, I used an audio signal generator to input single tones of various frequencies into my K3 in both LSB and DATA-A modes. I set the power control for 30W. Here are my measurements: AF input freq. Po-DATA-A Po-LSB TUNE 25.7 25.2 200 4.6 6.1 400 27.0 24.8 600 34.5 24.8 800 45.6 24.8 1000 53.1 24.8 1200 47.5 24.8 1400 37.8 24.8 1600 32.3 24.8 1800 30.9 24.8 2000 31.9 24.8 2200 34.3 24.8 2400 37.9 24.8 2600 34.9 24.8 2800 13.9 24.8 3000 nil nil So, neglecting the ~25 W vs 30 W error, it's clear that something is keeping a tight rein on things in LSB, but is not doing so in DATA-A. Presumably, this is the ALC action, which we are told is minimized in DATA-A mode. The data also seem to corroborate your statement that the calibration point is 300 Hz from the filter corner. If I'm really wrong about something, please correct me. If I'm NOT wrong, I think I might finally understand why power output in DATA-A doesn't seem to track the requested power closely. 73 -- Joe KB8AP On Feb 14, 2009, at 11:36 AM, Joe Subich, W4TV wrote: > > You CAN NOT make those tests at 50 Watts! The power calibration > circuitry will be constantly changing the internal gain. If > the ATU is enabled and/or your dummy load is not flat the changes > invalidate the measurements. > > Further, single tone power calibration is only accurate for > the specific frequency within the IF filter on which the > calibration is performed. If I calibrate power in CW mode > that calibration point is approximately 300 Hz from one > "corner" of the 2.8 KHz filter thanks to the way the K3 > offsets the filters. When I switch to DATA A, and try to > test the power level with a 1500 Hz tone, I can see 2 dB more > power simply because my 2.8 KHz filter has a 4 dB slope across > the passband and the K3 gain calculation includes compensation > for the loss at the calibration frequency. If I check the > power with a 1 KHz tone, the difference may be 3 dB (DATA A > is USB, CW calibration is LSB so the slope changes direction > with tone). If I switch to AFSK A (REV to stay with USB) > and check power with a 2295 Hz (USB Mark) tone, the difference > may be down to one dB or so. > > There are too many uncompensated variables to expect the K3 > to maintain absolute control over the power output with > changing antennas, power levels, modes, (relative) frequency > within the IF passband and possibly even different filters. > ALC controls the audio level into, and the RF level out of > the DSP (modulator) process - it is an ALC (automatic LEVEL > control) NOT an APC (automatic POWER control). > > The ALC is an open loop system - the loop gain is calibrated > once at the 5 watt level and once at the 50 watt level for > one specific frequency in the IF passband. Once that is > done, ALC simply controls the DSP gain. If you change the > system gain following the DSP, the output power level WILL > CHANGE. I'm sure it would be theoretically possible to > calibrate the system gain from 100 Hz to 2900 Hz offsets > from the carrier (for both the USB and LSB cases) and apply > that mask to the modulation process but does the DSP system > have enough horsepower to do so and is it worthwhile simply > so the operator can avoid the need to check his power level > when changing mode or modulating frequency? > > 73, > > ... Joe, W4TV > ______________________________________________________________ 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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In reply to this post by David Pratt
So, if I'm tuning up through, say, a Z-Match into a doublet and power output
is set to "around" 5 or 50W and press "Tune" in order to tweak the Z-Match, the initial (off-tune) complex impedance the K3 may see could very well cause the K3's output power to change to 5 or 50W and because of that, power indication would be screwed up without my noticing it? (Sorry for the long sentence, but BTDT.) Surely, for something that is a calibration feature, it needs to be protected by an "on/off switch"? It isn't as though this is a new topic. I've seen it crop up a number of times in different forms on this reflector and have been waiting for the Aptos wizards to make power calibration a menu item. Turn it on in the menu, have a few LED winky-blinkys to warn you're in Power Cal., do the job then turn it off in the menu. I suppose there's some horribly technical reason for not doing it. DaveL G3TJP Julian said: > Why on earth not? I think you are confusing the situation > with what happens when you press TUNE at 50 watts (which I > personally think is a disaster that has already happened > on many occasions, but that is another matter.) Joe said: To normalize the radio's output power for any valid test you need to measure the single tone carrier power (e.g., CW). If you do that (press tune at 50 watts), you will recalibrate. The recalibration will render any subsequent measurement incompatible with previous measurements. ______________________________________________________________ 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: K3 Beta firmware rev. 2.82
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> So, if I'm tuning up through, say, a Z-Match into a doublet > and power output is set to "around" 5 or 50W and press "Tune" > in order to tweak the Z-Match, the initial (off-tune) complex > impedance the K3 may see could very well cause the K3's output > power to change to 5 or 50W and because of that, power Not quite ... If you set the power level to exactly 5.0 or 50 watts and press the Tune button the K3 will recalibrate. If you set the power to 4.9, 5.1, 49 or 51 watts it will not recalibrate. > -----Original Message----- > From: [hidden email] > [mailto:[hidden email]] On Behalf Of David Lankshear > Sent: Saturday, February 14, 2009 7:56 PM > To: [hidden email] > Subject: Re: [Elecraft] K3 Beta firmware rev. 2.82 > > > So, if I'm tuning up through, say, a Z-Match into a doublet > and power output > is set to "around" 5 or 50W and press "Tune" in order to > tweak the Z-Match, > the initial (off-tune) complex impedance the K3 may see could > very well > cause the K3's output power to change to 5 or 50W and because > of that, power > indication would be screwed up without my noticing it? > (Sorry for the long > sentence, but BTDT.) > > Surely, for something that is a calibration feature, it needs to be > protected by an "on/off switch"? It isn't as though this is > a new topic. > I've seen it crop up a number of times in different forms on > this reflector > and have been waiting for the Aptos wizards to make power > calibration a menu > item. Turn it on in the menu, have a few LED winky-blinkys > to warn you're > in Power Cal., do the job then turn it off in the menu. I > suppose there's > some horribly technical reason for not doing it. > > DaveL G3TJP > > Julian said: > > Why on earth not? I think you are confusing the situation with what > > happens when you press TUNE at 50 watts (which I personally > think is a > > disaster that has already happened on many occasions, but that is > > another matter.) > > Joe said: > To normalize the radio's output power for any valid test you > need to measure the single tone carrier power (e.g., CW). If > you do that (press tune at 50 watts), you will recalibrate. > The recalibration will render any subsequent measurement > incompatible with previous measurements. > > ______________________________________________________________ > 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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Conclusion must be, never ever use 5.0W or 50W except
when calibration is needed. Why cant power calibration be turned off? Then we would not have this "source for trouble". / SM2EKM -------- Joe Subich, W4TV wrote: > >> So, if I'm tuning up through, say, a Z-Match into a doublet >> and power output is set to "around" 5 or 50W and press "Tune" >> in order to tweak the Z-Match, the initial (off-tune) complex >> impedance the K3 may see could very well cause the K3's output >> power to change to 5 or 50W and because of that, power > > Not quite ... If you set the power level to exactly 5.0 or 50 > watts and press the Tune button the K3 will recalibrate. If > you set the power to 4.9, 5.1, 49 or 51 watts it will not > recalibrate. > > ______________________________________________________________ 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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In reply to this post by Joe Subich, W4TV-4
I already stated that I ran the calibration on all bands at 5 and 50W prior to taking these measurements. There was no need to recalibrate when measuring the power on CW and DATA. In any case, the point of measuring the power on SSB was simply to illustrate that the power control works on SSB but not on DATA. OK. I didn't think you were suggesting that. But I did not invoke any automatic recalibration at any point during my tests.
I don't think that at all. I expect the power control to regulate the output power in the same way as it does for CW, AM, FM and SSB. If I set the power control to 50W and feed in an adequate level of input I expect to get no more than 50W out and preferably no less. How this is achieved is really not my concern. The amount of unpredictability of the output power in data mode at the moment is not acceptable. I can't imagine that this state of affairs would be considered acceptable if it was CW or SSB that was affected.
Julian, G4ILO. K2 #392 K3 #222 KX3 #110
* G4ILO's Shack - http://www.g4ilo.com * KComm - http://www.g4ilo.com/kcomm.html * KTune - http://www.g4ilo.com/ktune.html |
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In reply to this post by Joe Planisky
That amount of variability is alarming. I'm really not happy with it. But to me, that's not a 25W vs 30W error, it's a 30W vs 53W error. Because the output at 1KHz, which is the center frequency I use for PSK31, is 53W when 30W is requested. This is exactly what I am complaining about. If the power output at 1KHz matched the power level requested then I would be a lot happier, though it is quite disappointing to see that the power would be little more than half that level over most of the range that a Digipan user would operate in.
Julian, G4ILO. K2 #392 K3 #222 KX3 #110
* G4ILO's Shack - http://www.g4ilo.com * KComm - http://www.g4ilo.com/kcomm.html * KTune - http://www.g4ilo.com/ktune.html |
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In reply to this post by Joe Planisky
I have just run a set of tests across a range of audio frequencies as did Joe, KB8AP. The results were almost identical, so I am not going to tabulate them here. In SSB I adjusted the input level to give sufficient drive and just enough ALC action to result in a flat output from 600Hz to 2600Hz.
At the same time I checked the PSK31 IMD level across the spectrum using the KK7UQ IMD meter. I observed no degradation of IMD resulting from the use of minimum ALC to control the power to a flat level, compared to using DATA A mode where there is apparently no ALC feedback at all. Therefore it seems to me that the solution that has apparently been adopted in DATA A mode for the purpose of minimizing IMD is in fact producing no useful benefit at all, while at the same time depriving data users of a meaningful power control. I would much prefer the K3 to work the way other radios work, where you can increase the drive level until the ALC just starts, and then you know that you are producing the requested power and no more. This is how I believe it used to work in early versions of the firmware. DATA was just USB with a different input source option and compression automatically disabled. I will concede that the approach adopted by Elecraft is more foolproof in regard to avoiding IMD, but this is achieved at the cost of a loss of confidence in knowing the output power. However for me it is just too unsettling to not know how much power the radio is putting out, particularly as I wish to operate remotely via the network and can't see for myself the power output. I have had to give this up for the last few months after I found myself transmitting nearly 100W when I was intending to use 40W. If the majority of other data mode users are happy with the K3 the way it is and Elecraft can't or won't change it, then it's probably time for me to look for another radio.
Julian, G4ILO. K2 #392 K3 #222 KX3 #110
* G4ILO's Shack - http://www.g4ilo.com * KComm - http://www.g4ilo.com/kcomm.html * KTune - http://www.g4ilo.com/ktune.html |
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In reply to this post by David Pratt
Ah! I must have been on an exact 5W setting when I did it, then, Joe.
Thanks for clearing that up. I still think that as it's a calibration feature, it would make better sense by being protected by the ability to turn it off. I'd really like to hear why a calibration feature sits there awaiting to pounce on the unwary. 73 DaveL G3TJP I said: > So, if I'm tuning up through, say, a Z-Match into a doublet > and power output is set to "around" 5 or 50W and press "Tune" > in order to tweak the Z-Match, the initial (off-tune) complex > impedance the K3 may see could very well cause the K3's output > power to change to 5 or 50W and because of that, power ...... Joe replied: Not quite ... If you set the power level to exactly 5.0 or 50 watts and press the Tune button the K3 will recalibrate. If you set the power to 4.9, 5.1, 49 or 51 watts it will not recalibrate. ______________________________________________________________ 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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