KDSP2 Frequently Asked Questions



Q1. Do I need to modify my K2 for the KDSP2 to work??
A1. Not if you already have the KAF2 installed. If you do not have the KAF2 installed, the manual gives full instructions for the necessary modifications to the K2 Control Board.

Q2. Can I use the KAF2 and the KDSP2 in my K2?
A2. No, the KAF2 and the KDSp2 occupy the same physical location in the K2, and use the same connectors to the Control Board. You can only install one or the other at any given time.

Q3. Can I re-fit the KAF2 if I want to?
A3. Yes. The KAF2 and the KDSP2 are interchangeable with no additional modifications once either has been installed.

Q4. What capability does the KDSP2 give me that the KAF2 doesn't?
A4. The list includes: variable bandwidth; variable center frequencies; variable noise and notch reduction settings; mode-based filtering; four filters per mode.

Q5. If I customize the KDSP2 settings are they still there when I switch on the next time?
A5. All settings for all modes are 'sticky'. That is, they are stored in EEPROM as soon as they are entered.

Q6. Are there any settings not saved in EEPROM?
A6. The only settings not saved are the current filter selection and the time. The current filter selection is reset to filter 1 when you power up. Time and date are maintained by the real time clock.

Q7. Can the KDSP2 handle multiple heterodynes?
A7. Yes, but the more carriers to notch out the less the depth of the notch. The notch settings may be adjusted for better performance against multiple heterodynes at the expense of somewhat increased audio artifacts.

Q8. Does the KDSP2 have noise reduction in CW mode?
A8. Yes, noise reduction is available in both CW and SSB modes. It defaults to 'off' in both CW and SSB modes at initial turn on.

Q9. Why does it default off?
A9. If it defaulted on, you might think there was a problem in your audio when you first turned on the K2 after installing the KDSP2. Why? Because the background noise would be so much weaker than before...

Q10. Does it remember my denoiser settings?
A10. If the denoiser was on the last time you used the KDSP2, it will be on when you next use the KDSP2. See also the answer to question Q5.

Q11. I like the way the KAF2 sounds. Does the KDSP2 sound just as nice?
A11. Some operators think the KDSP2 "soft" filter settings at around 200 - 300 Hz bandwidth have a similar sound to the KAF2.

Q12. What happens if I really mess up the settings??
A12. The manual has a table of the default settings. They can easily be re-entered by the user.

Q13. How does it work??
A13. Very Well :-). Seriously, there is a good technical paper written by the designer at www.elecraft.com/KDSP2/kdsp2design.pdf.

Q14. What happens if there is an update to the firmware?
A14. The chips can be returned to Elecraft to be re-programmed for a nominal fee. As the DSP software is open source you could reprogram the DSP Flash yourself if you have the right equipment. The microcontroller firmware is not open-source, and must be reprogrammed by Elecraft.

12 May 2003