K1EL K44-SPLT Manual Download Page 4

 

K1EL             

K44 Audio Splitter Board Kit

K44-SPLT

K44 CW Reader Settings, or how to get the best copy out of your CWR

1)

The K44 CWR does not like noise

. If you set the signal level properly, noise will be less of

an issue. Before trying to copy any stations, find a frequency where there is no activity. If 
there is a lot of band noise, you may see the LEDs respond to the noise and climb up two
or three LEDs. This is a bad setup. Use the K44's gain adjustment (SHIFT+ENCODER 
CCW) to reduce the gain until either the first LED never or just barely lights. A gain 
setting of 3 is a typical high noise setting but it is highly dependent on the signal level you
feed into the K44. Once the gain is set correctly, you will find that the LEDs will respond 
accurately to CW signals and provide much better copy.

2)

Find the optimal gain setting in quiet band conditions

. Again find a quiet band spot and 

adjust the CWR gain until the first LED just barely lights. If you encounter very strong 
stations, you may have to reduce gain as described in the next paragraph.

3)

Avoid overloading the K44's CW decoder.

 Too much gain can be just as bad as not 

enough. In general, you should set maximum signal level to the point where the 5

th

 LED 

on the right just barely lights when a station is tuned in. This is the point where signal 
clipping first occurs. While the K44 CWR handles overload pretty well, reducing the gain 
gives you the narrowest filtering. If the signal increases beyond clipping, the 5

th

 and 1

st

 or 

2

nd

 LEDs will light at the same time. This is an extreme overload condition and can 

happen with very strong signals. You should back the CWR gain off to get the signal level
under control. In extreme cases you may need to reduce the receiver's RF gain setting.

4)

The CWR's noise filtering setting does matter

. This filter, adjusted by ALT-ENCODER, 

essentially controls the width of signal dropout correction. These dropouts are caused 
mostly by fast burst noise such as static crashes. These dropouts are very short in 
comparision to the width of a CW dit or dah and can be filtered out automatically. The 
higher the filter setting, the more aggressively dropout reduction is employed. Not 
surprisingly, very high settings will distort the CW integrity and will result in copy errors, 
especially at higher CW speeds (25 WPM and above). Our recommendation is to leave 
the filter at a low setting and use it only when there is a lot of atmospheric noise. 

5)

A receiver's automatic noise blanker does not help.

 Due to the way a noise blanker 

works, it really confuses the CWR and for that reason we suggest not using it. In addition,
a fast AGC setting should also be avoided. Fast changes in signal level will also confuse 
the CWR and affect copy. We suggest always using a slow attack AGC.

6)

Narrow CW filters are not always worth using

. Narrow CW filters (200 and 400 Hz) do 

ring and distort the detection timing of the CWR. If the detected element widths aren't 
correct then the CWR will make incorrect decoding decisions and misdecode letters. The 
CWR has a built-in 6 pole narrow bandpass filter and in most cases this is all you really 
need. That said, a good 2.3 KHz SSB filter with steep skirts does a good job in filtering 
out adjacent signals and in most cases that's all you will need.

The K44-SPLT is fully warranted to the original purchaser against defects in materials and 
workmanship for one year after purchase. This warranty does not cover damage caused by 
accident, improper care, or lightning damage. Please contact us before returning your K44-SPLT 
for repair and we will issue an RMA. 

Please submit support questions by e-mail to: [email protected] 

While every effort has been made to insure that the K44-SPLT design is safe and the 
documentation is clear and accurate, it is still possible to cause equipment damage or incur 
personal injury if

a) K44-SPLT is not used as intended 
b) K44-SPLT is connected incorrectly
c) K44-SPLT is modified in any way

K1EL Systems can not be held responsible in these or similar events.

K44-SPLT Manual A.1

8/14/2018

Page 4

Summary of Contents for K44-SPLT

Page 1: ...match To solve this once and for all we designed an audio splitter board which takes the place of a Y cable and also solves the impedance mismatch problem Unfortunately it doesn t solve the AF gain adjustment issue but it s a good compromise The K44 Splitter board has three 1 8 inch jacks one jack goes to your radio s external speaker jack a second one goes to you exernal speaker and a third goes ...

Page 2: ...best way to do this is to first tack solder one pin to hold the connector in place and then solder the remaining pins Finally install the audio transformer This must be oriented correctly for it to work properly Note the GD marking on the top of the transformer Rotate T1 so that the position of the GD marker matches the picture above That completes the assembly recheck your component placement and...

Page 3: ...bing closeup Here we have connected the K44 SPLT to an IC 7300 s external speaker jack and are using a Radio Shack external speaker Note that the connection to the K44 is very simple just one cable from K44 SPLT J2 to K44 Audio Input Revision History Manual Rev A 1 Initial Release K44 SPLT Manual A 1 8 14 2018 Page 3 ...

Page 4: ... by fast burst noise such as static crashes These dropouts are very short in comparision to the width of a CW dit or dah and can be filtered out automatically The higher the filter setting the more aggressively dropout reduction is employed Not surprisingly very high settings will distort the CW integrity and will result in copy errors especially at higher CW speeds 25 WPM and above Our recommenda...

Page 5: ...K1EL K44 Audio Splitter Board Kit K44 SPLT K44 SPLT Schematics K44 SPLT Manual A 1 8 14 2018 Page 5 ...

Page 6: ...d before you start Inventory the kit parts make sure you have ALL of them 4 Follow the assembly instructions in order Although not always obvious the order in which parts are added to a board is important and should be followed Sometimes sections are installed and tested in order or there could be a mechanical clearance consideration 5 Keep your Workplace Clean and Orderly Nothing spoils a kit bui...

Page 7: ...ture Wear safety glasses to protect your eyes from flying objects Appendix C Soldering Basics 1 Insert component leads into PCB holes and bend them back slightly to hold the part in place You can either trim the lead now or wait till after the joint is soldered I usually install several parts at one time and then solder and trim multiple leads 2 Place a hot and clean iron tip against both the lead...

Page 8: ...en remove the iron Fig C3 Remove the solder 6 Allow the joint to cool and visually inspect for defects or other problems You should have a solder joint with a bright shiny finish and a profile like that shown in the middle picture below Fig C4 Solder quantity comparison K44 SPLT Manual A 1 8 14 2018 Page 8 ...

Page 9: ...aterials 2 Figure 3 K44 Audio Splitter cabing example 3 Figure 4 K44 Audio Splitter cabing closeup 3 Revision History 3 K44 CW Reader Settings or how to get the best copy out of your CWR 4 K44 SPLT Schematics 5 5 Appendix A Kit Construction Hints 6 Appendix B A Note About Safety 7 Appendix C Soldering Basics 7 K44 SPLT Manual A 1 8 14 2018 Page 9 ...

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