QSK and Semi-Breakin Timing Analysis 

Taking a look at CW element spacing with the latest firmware

  

Yaesu comes to the QSK user's rescue with a quick fix to the problems identified on the Yahoo board and documented in the earlier report (below).  In that prior firmware, the semi-breakin timing was close to ideal but the QSK was quite far off from the target of 3:1:1.

Today we put the new firmware to the test.  To see how close to 3:1:1 the timing is; and to check the consistency between semi-breakin and full QSK.

  

Test setup - identical to before except for updated firmware as follows:

  • FT-DX5000MP - lot 21
  • Firmware - control v119, EDSP v537
  • DSO capture and measurement from RF emission - 200W
  • 30 WPM
  • 6 mS rise time menu setting
  • 3.0 weighting menu setting
  • Hantek DSO; measurements are accurate to 0.2 mS 

  

Menu settings:

63 - BK-IN

64 - Shape

65 - Weight

  

  

 Internal Keyer Results

The test procedure is the same as with the prior test sequence. So I will give the screen captures below for reference and provide the results here.  

In each column set, the old firmware results are shown, then the new firmware results, and then a slightly improved WEIGHT setting (menu 65) of 1:3.1 (highlighted in yellow).

As I measured the spacing, the weight between dot-dash was slightly light on the dash.  Moving the weight to 3.1 provided nearly a perfect timing set.  3.2 weighting setting pushes the dah:dit ratio to about 3.06.  Your choice - set and forget.

  

  

Element/Item

Full

Full

Full

Semi

Semi

Semi

Firmware - CTL/EDSP

118/533

119/537

119/537

118/533

119/537

119/537

WEIGHT menu setting

3.0

3.0

3.1

3.0

3.0

3.1

DSO:  Space Width

48

41

40

40

40

41

DSO:  Dit Width

36

43

43

43

43

43

DSO:  Dash Width

115

121

127

121

123

127

Dit:Space Ratio

0.75

1.05

1.08

1.08

1.08

1.05

Dah:Dit Ratio

3.19

2.81

2.95

2.81

2.86

2.95

  

There are two important findings from this firmware:

1. The waveform is identical in both the QSK and SEMI modes.  Which means whatever small adjustment to personal preference (e.g. weighting), the transmitted waveform will be the same in either mode. 

2. The DOT:DASH:SPACE ratios are very close to ideal.  The firmware provides for a slightly heavy weighting but well within acceptable limits.

3. By my measurements, the ability to hear between the elements is preserved.  In fact, using the informal method based on the AF waveform height vs. speed, I measured a slightly improved ramp rate vs. the prior firmware versions.  Full AF waveform height was possible in the new firmware up to almost 30 WPM vs. about 25 WPM in the prior version.  

  

  External Keyer Results

  

The external keying rig results are shown here. 

Rig is fed to the rear jack by the uHam MKII keyer.  The output keying from the MKII is within 0.5 mS of ideal 3:1:1 as you can see in the graphic below:

  

  

So the skew we see in the results is from the rig.  The net effect is somewhat heavier weighting.  Fortunately, the QSK and SEMI mode effects in this firmware version are the same - so adjusting the MKII is easy.  The final MKII adjustments used are shown in the table (yellow).

  

Element/Item

Full

Full

SemiW

MKII - WT

50%

45%

50%

MKII - DOT:DASH

300

302

300

DSO:  Space Width

37

41

36

DSO:  Dit Width

45

40

45

DSO: Dash Width

124

119

125

Dit:Space Ratio

1.22

0.98

1.25

Dah:Dit Ratio

2.76

2.98

2.78

  

In the default MKII configuration (50%, 300), the weighting sounds nice to my ear - but as I explain the earlier work (below), a heavier weighting is my preference.  For users who are externally keying, they may prefer a slightly lighter weight and most advanced keyers provide this functionality.  

Given the consistent behavior of the rig with external keying, and the default toward a classic slightly heavier weighting, I don't consider this a significant shortcoming with the firmware.

  

 Conclusion - v119/537 Firmware

I think Yaesu has the right formula in this firmware version.

Internal keyer timing is near perfect and consistent in mode.  And the QSK recover time is as good or better than before.

These is exactly what we were needing!

External keying timing is a bit on the heavy side - but I believe many would consider this an "acceptable" performance level.  

Thanks Yaesu for making a great rig even better!

And given finite firmware development resources, I would personally prefer Yaesu call the QSK concerns "addressed and solved" - and to now look into what I consider much bigger issues for the CW op - specifically the APF and the filter width functionality/ergonomics.

  

 DSO Captures of Pre/Post Firmware Update

  

Screen shots below show a dot-dash repeating sequence.  First the old firmware, followed by the same view with the new firmware.  To gather the data presented in the table above a direct-measurement tool provided by the DSO allows for the exact value to be read from the capture.  

  

Semi - v118/533 firmware (below)

  

Semi - v119/537 firmware (below)

  

QSK - v118/533 firmware (below)  

  

QSK - v119/537 firmware (below)

  

  

  

  

  

  

  

  

  

  

!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

  

PRIOR FIRMWARE RESULTS

  

!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

  

Test setup:

  • FT-DX5000MP - lot 21
  • Firmware - control v118, EDSP v533
  • DSO capture and measurement from RF emission - 200W
  • 30 WPM
  • 6 mS rise time menu setting
  • 3.0 weighting menu setting
  • Hantek DSO; measurements are accurate to 1 mS

  

Menu settings:

63 - BK-IN

64 - Shape

65 - Weight

  

  Internal Keyer Measurements

  

Measurements were first made on the rig's full-break in ("QSK" BK-IN menu 63 setting).  Screens and data looked like this:

  

Full break-in, space measurement

  

Full break-in, dit measurement

  

Full break-in, dah measurement

  

The dah:dit ratio is somewhat close to ideal 3:1, but the spacing of the elements is quite high by comparison.  Adjusting the WEIGHT ratio (menu 65) to 2.8 provided a better dah:dit ratio (yellow cells, below) - but the element spacing remains too wide.

Spacing of QSK break-in elements are long with respect to  ideal spacing by about 35%.  This is the fundamental problem with the current controller firmware.   

In SEMI break-in, the spacing is much closer to ideal with respect to element spacing.  A slightly heavier dah:dit ratio of WEIGHT menu 65 setting 3.3 gives a much better overall result.

Note that the Yaesu menu 65 is not a true "weight" in the classic tradition - but is more accurately a dit-dah ratio.  The space and dit remain fixed; with the dah length changing with menu setting.

  

Element

Full

Full

Semi

Semi

Key menu setting

3.0

2.8

3.0

3.3

Space Width

48

48

40

41

DSO:  Dit Width

35

35

43

43

DSO:  Dah Width

115

106

122

126

Dit:Space Ratio

0.73

0.73

1.08

1.08

Dah:Dit Ratio

3.29

3.03

2.84

2.93

  

  

 External Keyer Measurements

  

Measurements using the rear panel external key input were taken next. Feeding the rig was a Microham MKII with the Winkey v10 chip. Manual keying as well as logger-driven keying of the rig via the MKII will provide the timing shown below. 

Adjustments in the MKII settings were made to optimize the element spacing (red cells). 

Optimum settings for standard 1:1:3 weighting are given in the table.  The element timing is pretty different between QSK and SEMI settings such that it's not practical to keep the same settings and move between SEMI and QSK settings and hope to get near proper timing ratios.

I prefer a bit heavier overall weighting and settings suitable for interested ops are included in the "Heavy" titled columns.

 

Element

Full

Std

Full

Heavy

Semi

Std

Semi

Std

Semi

Heavy

WK Dit/Dah Ratio

306

320

306

307

335

WK Weighting %

54

60

54

47

54

Space Width

41

38

35

41

34

DSO:  Dit Width

41

44

47

41

46

DSO:  Dah Width

121

129

127

122

138

Dit:Space Ratio

1.00

1.16

1.34

1.00

1.35

Dah:Dit Ratio

2.95

2.93

2.70

2.98

3.00

  

Note that there is quite a bit of interaction between the two WK settings and the results as seen on the transmitted RF. 

  

 1st Dit Measurements

  

Shown here a measurement of the first and second dits.

  

  

Element

Int

Full

Int

Semi

Ext

Full

Ext

Semi

1st Dit

34.8

42.2

42.6

42.6

2nd Dit

35.0

41.8

43.8

43.8

1st:2nd Ratio

0.99

1.01

0.97

0.97  

  

In the internal keyer case, there is no significant difference.  In the external keyer case, only a minimal difference is noted (and is within the measurement error).  Good job here Yaesu.

  

 Rise Time Measurements

  

4 mS setting gives roughly 2.5 mS actual rise time

  

  

6 mS setting gives roughly 3.8 mS actual rise time

  

  

Fall time is slightly less than 2 mS in both cases

  

  

Rise times are specified at 10%-90% and were eye-ball interpolated here.  The contribution to error by threshold differences is not significant.

The rise and fall times (very short vs. menu setting) is similar to what I had measured with the 2K.  These values have been independently verified by Sherwood in prior published work.

  

 Conclusions

  

Actual rise time is about 2/3 of the menu setting

The first element is not shortened significantly vs. subsequent elements

SEMI break-in setting are reasonably close to 1:1:3 ideal spacing

Spacing of QSK break-in elements are long with respect to ideal spacing by about 35%

  

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