Better transmit audio processing for Amateur Radio

1. “Better Transmit Audio
Processing Techniques”
…what’s it about, why the controversy and tips for getting started
Originally presented at the October 7, 2003, Meeting of the Murray State University Amateur
Radio Club and later revised November 28, 2012 for publication on the Internet
by Don Snodgrass, KG9OM
donsno@joomlapatterns.com | http://www.k4qky.com/kg9om/

2. Introduction
Better transmit audio
processing techniques
have gained considerable
popularity over the past
ten years.
 Studio quality
microphones and external
audio processing choices
 hardware or software based
 Now incorporated into
most new HF transceiver
design
 Learning more about
emerging new computer
assisted technologies

3. Overview
What constitutes better
transmit audio processing
Why the controversy
Resolving the issues
Recommendations for those
who want to learn more
about better transmit audio
processing
Questions?

4. What constitutes better transmit audio
processing?
Conventional transmit audio processing tends to emphasize the mid
range and typically sounds stringent. Narrow range communication
grade microphones and built-in speech processors are often the
norm.
Better transmit audio processing is aimed at balancing the low, mid
and high frequencies of the human voice.
 Can be accomplished with the use of hardware and even software
based audio processing techniques aimed at achieving a more
pleasing, natural and articulate sound.
 Full range microphones Click to edit Master text style
 External hardware including microphone preamps and effects
processors
Second leve
 Programmable EQ’s included in the design ofnewer HF transceivers Third level
such as the Kenwood TS-590
• Fourth level
 External software based audio processing programs such as
“Ableton Live”  Fifth leve

5. Result
Click to edit Master text styles
Second level
 Third level
• Fourth level
 Fifth level
Balanced (flat) frequency response from 80 hz to 3.0 Khz
with greater talk power with a more natural sound

6. Why the controversy?
What’s good about audio What’s Not so good
processing  Hams who have modified
 Advances the state of the their transmitters to extend
radio art their transmit bandwidth well
 Provides for beyond 3 Khz are more likely
experimentation… to interfere with other nearby
especially software based QSOs especially during
processing systems. crowded band conditions.
 More pleasant to listeners
 Promotes greater  Hams who prefer
awareness of good conventional sounding audio
operating practices often openly ridicule those
 Reduced IMD who experiment with the
techniques described herein.

7. Resolving the controversy
 Part 97 is vague on many things
including transmit bandwidth. Perhaps it
should remain so to foster the
continuance of our long and proud
tradition of self-regulation.
 We need to be more tolerant of each
other’s operating choices and styles.
 Besides, our hobby has bigger fish toClick to edit Master text styles
fry
including cracking down on: Second level
 Intentional interference
 Third level
 Foul language
• Fourth level
 Poor operating practices
 Fifth level

8. Tips for getting started
Achieving better transmit audio processing
is not for everyone. However, those who
may be interested, should first learn more
about it:
 Visit websites including:
 http://www.nu9n.com/intro.html
 http://www.w3oz.com/v1enhanced%20audio%20main.htm
 http://groups.yahoo.com/group/ssbaudio/
 Talk with other hams who enjoy
experimenting with these techniques

9. Then, determine hardware and/or
software needs
External hardware processing:
• Full range microphone
• Microphone preamp
• Audio EQ, compressors and other
effects processors
• Necessary cabling, etc.
Internal systems:
• Full range microphone
• Microphone preamp (optional)
• A newer transceiver with an effective
built-in EQ (e.g. Kenwood 590)
Software based systems: (For some, a good alternative to
using hardware)
• Full range microphone (Consider a USB
microphone such as the AT2020 USB)
• Ideally a transceiver with USB
connectivity (e.g. Kenwood 590) If not, then
purchase a USB interface (e.g. E-MU 0204)
• Software program such as “Ableton
Live” and “Breakaway Live Audio
Processor”

10. Conclusion
Experimenting with better transmit
audio processing techniques can add to
your enjoyment of Amateur Radio.
Moreover, you will improve your signal
quality while learning more about this
exciting and highly customizable
technology.

11. Questions, comments or requests…
Visit KG9OM’s website at http://www.k4qky.com/kg9om/ , email
donsno@joomlapatterns.com or call 618-524-7590