Timewave DSP-599zx User manual

DSP-599zx
Audio Noise
Reduction Filter
Operating Manual
March 6, 1997
TECHNOLOGY INC.

Congratulations You have purchased the most advanced digital signal processor available.
Please complete and return the enclosed Warranty Registration Card. Time-
wave Technology Inc. occasionally offers performance enhancing updates
to its products. By returning the completed Registration Card, we will notify
you about theseupdates.For currentinformation and hints andtipsabout our
products check out our World Wide Web site.
If you are in a hurry to use your new equipment, turn to the Quick Start sec-
tion. It provides enough information to get your new equipment up and run-
ning. You still will want to read through the rest of this manual. It provides
valuable operation tips and information that will allow you to use the fea-
tures to full measure.
Serial Number You will need your serial number when communicating with Timewave
Technology, Inc. The number is on the bottom of the DSP-599zx. It is also
stored within the unit and is displayed when you power up your unit. Record
your serial number on your registration form and here for future reference.
DSP-599zx Serial Number: ________________________
Copyright (1994,1995,1996,1997, 2002 by TimewaveTechnology Inc.Allrights reserved.
Printed in USA
Under thecopyright laws, this manual can’tbe reproduced in any form with-
out prior written permission from Timewave Technology Inc.
Timewave Technology Inc. strives to deliver the best product to ourcustom-
ers. As part of this goal, we are constantly trying to improve our products.
Timewave Technology Inc., therefore, reserves the right to make changes to
product specifications or documentation without prior notice.
This manual may contain errors, omissions or “typos.” Please send your
comments, suggestions and corrections:
Timewave Technology Inc.
501 W. Lawson Ave.
St.Paul,MN55117 U.S.A.
[e-mail]-mail
http://www.timewave.com FAQ and General and Update Information
[phone] Voice
[phone] Fax

DSP-8100c Audio Noise Reduction Filter
March 6, 1979 Quick Start-iii
Quick Start
“I don’t want to read the whole manual just to turn it on.”
You have purchased the most advanced digital signal processor available.
Please complete and return the enclosed Warranty Registration Card. Time-
wave Technology Inc. occasionally offers performance enhancing updates
to its products. By returning the completed Registration Card, we will notify
you about theseupdates.For currentinformation and hints andtipsabout our
products check out our World Wide Web site.
If you are in a hurry to use your new equipment, read this Quick Start sec-
tion. It provides enough information to get your new equipment up and run-
ning. You still will want to read through the rest of this manual. It provides
valuable operation tips and information that will allow you to use the fea-
tures to full measure.
What is packed with your DSP-599zx
• DSP-599zx
• Operator Manual (what you are now reading)
• Warranty Registration Card
• 5.5 x 2.1 mm power connector
What is not packed with your DSP-599zx that you will need
• 12-16 Volt dc power supply capable of providing a minimum of 1 am-
pere. Most commercial power supplies produce 13.8 Vdc and are rated
as 12 Vdc. Please see page 2-2 for more information.
• Two-conductor cable to connect between power supply and DSP-599zx
• Cables to connect DSP-599zx with your transceiver speaker output,
PTT output, external speaker and multimode controller. All of these ca-
bleswill need a RCA typeconnector on theend that attaches to the DSP-
599zx. The other connector will vary with the equipment on the other
end. Consult your owner’s manuals.
• External speaker and/or headphones. You will need at least one of these
devices to connect to the DSP-599zx to hear the audio signal. The DSP-
599zx will accept either stereo or mono headphones with a 1/4” plug.
Stereo headphones are the preferred choice because of the dual out-
put channels. External speakers are connected to the unit with RCA
phono plugs. You may need an adapter to convert an existing speaker to
this type of connector.
• In some datamodes you will need a cable from the 8-pin DIN connector
to your transceiver.You may also need a 9-pin serial cable to connect to
your computer.
March 6, 1979

Quick Start – “I don’t want to read the whole manual just to turn it on.”
Quick Start-iv March 6, 1979
Consult the installation section of this manual for more information on ca-
bles and connections.
Power
12-16 Vdc
RS-232 Radio A
Radio B
PTT
Input
A
B
Audio
Input Line Ouput Speaker
Ouput
Headphones
Timewave Technology Inc.
St. Paul, Minnesota USA.
599-010
Multimode Controller
Rx Audio Input
(PK232, KAM +, or other)
Typical
Transceiver
PTT Out ANT Ext Sp
See your Operator Manual
for specific information
about PTT output connections
Speaker
12-16 Vdc 1A
Power
Supply
Center Cond +12Vdc
To Stereo/Mono
Headphones
DSP-599zx
See your Operator
Manual for specific
connector information

DSP-8100c Audio Noise Reduction Filter
March 6, 1979 Quick Start-v
Quick Start Setup Here is the absolute minimum information you need to get started. After you
satisfy your urge to hook it up and turn it on please read the entire manual.
There are two reasons for the request. First; you will learn how to maximize
the effectiveness of this fine product. Second; you paid for this manual so
you might want to get your money’s worth.
1. Before connecting the DSP-599zx, tune in a signal on your receiver
and adjust it for your normal listening level.
2. Connect the speaker output of your radio to Channel A audio input of
the DSP-599zx. Use a RCA phono connector on the DSP-599zx end
of the cable.
3. Connect the Channel A audio output to your 4 or 8 ohm loudspeaker.
Use a RCA phono connector on the DSP-599zx end of the cable.
4. Connect a 12-16 Vdc 1 Ampere power supply to the DSP-599zx. Use
a 5.5 x 2.1 mm power connector on DSP-599zx end of the 12-16 Vdc
power cable. The center pin must be positive (+). (There is a 5.5 x
2.1 mm connector packed with the DSP-599zx manual.)
5. Turn on the DSP-599zx power (volume control,rightside of frontpan-
el).
6. Adjust theradio volume control until the yellow LED on the right side
of the DSP-599zx panel flashes but the red LED flashes rarely.
7. Adjust the DSP-599zx volume control for comfortable listening.
8. Select the Voice, CW or Data mode on the DSP-599zx by pressing the
Mode switch on the upper left front panel to light the corresponding
LED above the display.
9. Try pressing the random noise reduction and tone notch switches, and
adjusting filter tuning knobs to operate the various filter features of the
DSP-599zx.
10. You can select many more features by using the rest of the switches
and the display menus.
For best results, read the manual now!

Quick Start – “I don’t want to read the whole manual just to turn it on.”
Quick Start-vi March 6, 1979
Voice Mode
Typical display for Voice mode, 300 Hz to 2700 Hz filter, Achannel active
and speaker on.
CW Mode
Typical display for CW mode, Center Frequency at 800 Hz and Bandwidth
set to 100 Hz filter, A channel active and speaker on.
Data Mode
Typical display for RTTY Data mode. Center frequency at 2210 Hz, offset
at 170 Hz andbaud rate of 45. Achannel isactive and speaker on. Bandwidth
has been adjusted wider than normal.
Function
6
Shift
5
AGC
3
Bypass
Setup
TestData
DSP-599zx
CW
Voice
Mode
Rcl/Store
Spkr/Chan
1
Random
4
Tone
2
599-006
High Pass
Center Freq
Time
Function
6
Shift
5
AGC
3
Bypass
Data
DSP-599zx
CW
Voice
Mode
1
Random
4
Tone
2
599-007
Setup
Test
Rcl/Store
Spkr/Chan
High Pass
Center Freq
Time
Function
6
Shift
5
AGC
3
Bypass
Data
DSP-599zx
CW
Voice
Mode
1
Random
4
Tone
2
599-029
Setup
Test
Rcl/Store
Spkr/Chan
High Pass
Center Freq
Time

DSP-599zx Audio Noise Reduction Filter
vii
Table of Contents
“I don’t want to read the whole manual just to turn it on.” iii
What is packed with your DSP-599zx .........................................................................iii
What is not packed with your DSP-599zx that you will need ...................................iii
Quick Start Setup ...........................................................................................................v
Voice Mode ....................................................................................................................vi
CW Mode .......................................................................................................................vi
Data Mode ......................................................................................................................vi
Introduction 1-1
Digital Signal Processing............................................................................................ 1-1
DSP-599zx Overview ..................................................................................................1-1
Signal Flow ..............................................................................................................1-2
Front Panel Controls ..................................................................................................1-3
Back Panel Connectors............................................................................................... 1-4
Features Common to All Modes ................................................................................1-5
Random/Tone Noise Reduction ...............................................................................1-5
Adaptive Multi-tone and Manual Notch Filtering (Tone noise reduction) ..............1-5
Dual Channel Operation ..........................................................................................1-5
Visible Memories .....................................................................................................1-6
Automatic Gain Control ..........................................................................................1-6
Bypass Control .........................................................................................................1-7
Operating Modes .........................................................................................................1-7
Voice Mode .............................................................................................................1-8
Highpass/Lowpass Filters .....................................................................................1-8
Random Noise Reduction .....................................................................................1-8
Adaptive Multi-tone and Manual Notch Filtering (Tone noise reduction) ...........1-9
CW Mode .................................................................................................................1-9
Bandpass Filters ....................................................................................................1-9
Random Noise Reduction ...................................................................................1-10
Manual Notch Filtering .......................................................................................1-10
Marker Tone ........................................................................................................1-10
CW Tone Pitch Shift ...........................................................................................1-10
Data Mode .............................................................................................................1-11
Bandpass Filters ..................................................................................................1-11
Data Tuning Function .........................................................................................1-12
Random Noise Reduction ...................................................................................1-12
RTTY Modem .....................................................................................................1-12
RTTY Remodulator ............................................................................................1-12
RTTY FSK Test Signals .....................................................................................1-13
Test Instrument Mode ............................................................................................1-13
Audio Millivoltmeter ..........................................................................................1-13
Audio Signal Generator .......................................................................................1-14
Two-Tone Generator ...........................................................................................1-14
CTCSS Tone Decoder .........................................................................................1-14
Set-up Mode ...........................................................................................................1-15

Table of Contents
viii
Installation 2-1
Power Supply ...............................................................................................................2-2
Connecting Cables .......................................................................................................2-2
Wiring information ..................................................................................................2-2
DSP-599zx Inputs and Outputs .............................................................................2-2
Transceiver Speaker Output ..................................................................................2-3
External Speaker ...................................................................................................2-3
Multimode Data Converter and Terminal Units (TU) ..........................................2-3
Transceiver PTT and T-R Outputs ........................................................................2-3
Audio Input ..................................................................................................................2-4
Input Impedance Setup ............................................................................................2-4
Input Impedance Jumper Access ...........................................................................2-4
Audio Input Signal Level Setup ...............................................................................2-5
Audio Output ...............................................................................................................2-5
Headphone Jack .......................................................................................................2-5
Headphone Volume Jumper Access ......................................................................2-6
Speaker Outputs .......................................................................................................2-7
Line Outputs ............................................................................................................2-7
Input/Output Options .................................................................................................2-7
Speaker/Headphone .................................................................................................2-7
Line Output ..............................................................................................................2-8
PTT Input ....................................................................................................................2-9
RTTY Modem Input/Output ...................................................................................2-10
DIN Jacks - Radio A and Radio B .........................................................................2-10
RS-232 Connector ..................................................................................................2-10
Setup - Install .............................................................................................................2-11
Audio Input Signal Level Setup .............................................................................2-11
Line Out Signal Level Setup ..................................................................................2-12
Speaker/Headphone Routing .................................................................................2-13
Alternate Channel Gain .........................................................................................2-14
Line Out Routing ...................................................................................................2-15
Reset Memory ........................................................................................................2-16
Exit Setup ...............................................................................................................2-16
General Operation 3-1
Introduction .................................................................................................................3-1
Front Panel Operation ..............................................................................................3-1
Controls Common to All Modes and Features .........................................................3-2
Primary Operating Modes [Mode] ...........................................................................3-2
Secondary Operating Modes and Features [Shift] ...................................................3-2
Speaker Control [Spkr/Chan] ...................................................................................3-2
Channel Control [Spkr/Chan] ..................................................................................3-3
Memory Operation [Rcl/Store] ................................................................................3-3
User Selectable Power Up Mode .............................................................................3-5
Bypass [Bypass] .......................................................................................................3-5
Automatic Gain Control [AGC] ..............................................................................3-5
Noise Reduction .......................................................................................................3-6
Power Switch/Gain Adjust Control .........................................................................3-6

DSP-599zx Audio Noise Reduction Filter
ix
Voice Mode 4-1
Operation .....................................................................................................................4-1
High Pass/Low Pass Filters ..................................................................................... 4-1
Noise Reduction .......................................................................................................4-2
AM Line Noise ........................................................................................................4-3
Heterodyne Elimination/Notch Filters .....................................................................4-4
Automatic Notch Filter .........................................................................................4-4
Manual Notch Filter ..............................................................................................4-5
Voice Bypass ...........................................................................................................4-6
Setup - Voice ................................................................................................................4-6
AM Line Noise ........................................................................................................4-7
Exit Setup .................................................................................................................4-7
CW Mode 5-1
Operation .....................................................................................................................5-1
Bandpass Filters .......................................................................................................5-1
Noise Reduction .......................................................................................................5-2
Manual Notch Filter .................................................................................................5-2
CW Marker Tone..................................................................................................... 5-3
CW Tone Pitch Shift ................................................................................................5-3
CW Bypass Mode ....................................................................................................5-4
Setup - CW................................................................................................................... 5-5
Marker Tone Level ..................................................................................................5-5
Exit Setup .................................................................................................................5-5
Data Mode 6-1
Introduction .................................................................................................................6-1
Operations Common To All Data Types ..................................................................6-1
Basic Data Mode Operation .....................................................................................6-1
Data Settings Display ..............................................................................................6-2
Data Tuning Function ..............................................................................................6-2
Random Noise Reduction........................................................................................ 6-3
Data Bypass Mode ...................................................................................................6-3
Data Filter Mode .........................................................................................................6-4
RTTY, AMTOR, SITOR, PacTOR, G-TOR ...........................................................6-4
HF Packet .................................................................................................................6-5
CLOVER .................................................................................................................6-5
SSTV and WeFAX ..................................................................................................6-5
RTTY FSK Test Signals ..........................................................................................6-5
RTTY Modem Operation ...........................................................................................6-6
RTTY Remodulator Operation ..................................................................................6-7
Data Operating Hints ................................................................................................. 6-8
Data Primer ..............................................................................................................6-8
Frequency shift ......................................................................................................6-8
Center Frequency ..................................................................................................6-8
Baud Rate ..............................................................................................................6-9
QRM Operating Hint............................................................................................... 6-9
Mark Space Frequencies ..........................................................................................6-9
Setup - Data Mode .................................................................................................... 6-10
Speaker Mute/Bypass ............................................................................................ 6-10
Modem Assignment ...............................................................................................6-11
FSK Mark Control .................................................................................................6-11

Table of Contents
x
Configuring Data Operating Modes ......................................................................6-12
Exit Setup ...............................................................................................................6-14
Test Instrument Operation 7-1
Audio Millivoltmeter ...................................................................................................7-1
Operation .................................................................................................................7-2
Sine Wave Generator ..................................................................................................7-3
Two-Tone Generator ..................................................................................................7-4
CTCSS Decoder ...........................................................................................................7-5
Autodetect ................................................................................................................7-5
Autodetect Display with Input CTCSS Tone........................................................ 7-6
Tone Squelch ...........................................................................................................7-6
CTCSS Tone Squelch Selection ............................................................................7-6
CTCSS Tone Squelch Detection ...........................................................................7-6
CTCSS Tone Squelch ...........................................................................................7-7
CTCSS Tone Squelch Switch Output Jack and Pin Numbers ..............................7-7
What are CTCSS tones? ..........................................................................................7-7
CTCSS Tone Frequencies - Hz............................................................................. 7-8
Setup - Test Instrument ..............................................................................................7-8
Default CTCSS Tone ...............................................................................................7-9
CTCSS Trigger Threshold .......................................................................................7-9
Signal Generator Calibration .................................................................................7-10
Millivoltmeter Calibration .....................................................................................7-11
Exit Setup................................................................................................................7-12
Troubleshooting 8-1
Common Problems and Solutions. ............................................................................8-1
Nothing comes on when I turn on the power. ..........................................................8-1
"Normal" LED does not flash on audio peaks. ........................................................8-2
"Overload" LED flashes constantly on audio peaks. ..............................................8-2
No audio output .......................................................................................................8-2
It still does not work! ...............................................................................................8-3
Specifications A-1
Glossary A-3
Product Warranty A-5
Exclusive Remedies: ...............................................................................................A-5
Electromagnetic Interference A-7
Schematic Diagrams A-9

DSP-599zx Audio Noise Reduction Filter
March 6, 1997 1-1
1
Introduction This section includes a short summary of both the front panel controls and
the rear panel connectors. It also provides an overview of the features found
in the DSP-599zx. Please see Appendix A–Specifications for detailed infor-
mation on the capabilities of the DSP-599zx.
Please turn to Section 2–Installation for detailed installation and Setup of
your new unit. If you are in a hurry to start using the DSP-599zx, turn to sec-
tion two after you have read the first four pages of this section. Return to this
section to review all the features and capabilities.
Digital Signal Processing
Digital Signal Processing (DSP) is a powerful and complex method of ana-
lyzing and modifying analog signals. Audio signals like speech or radio data
are analog signals. The speech and data signals have fairly well known and
predictable characteristics; however, these characteristics arequite complex.
By converting the analog signal to a digital signal, a powerful digital signal
processor with a special program can analyze the characteristics of the ana-
log signal. The digital signal processor can then modify the digital signal to
enhance desired characteristics and to remove undesirable characteristics
suchas noise. Theprocessed signal is converted back to an analogsignal and
sent on to a speaker,headphone, or data controller. The result is a signal with
less noise and/or fewer data errors. In amateur radio terms, DSP is capable
of reducing or eliminating QRN (noise) and QRM (interference).
For a more detailed discussion of digital signal processing, consult the most
recent ARRL Handbook.
DSP-599zx Overview
The DSP-599zx is an extraordinarily versatile digital signal processor de-
signed for amateur and shortwave radio voice, data, and CW operation. The
DSP-599zx uses advanced digital signal processing technology to imple-
ment algorithms that perform five basic audio functions:
• Random noise reduction
• Adaptive multi-tone and manual notch filtering (Tone noise reduction)
• Bandpass/Highpass/Lowpass filtering
• Signal generation including RTTY modulation
• Signal detection and measurement including RTTY demodulation
The DSP-599zx combines these five basic functions to reduce noise and in-
terference and improve radio communication.The DSP-599zx hardware and
software architecture allow easy field upgrade with new features and algo-
rithms. The same hardware and software architecture also allow ergonomic
March 6, 1997

1 – Introduction
1-2 March 6, 1997
mode oriented operation of the DSP-599zx. The LCD alphanumeric display
provides a clear view of operating settings when switching between operat-
ing modes. The quick-select push buttons and optical encoders for filter tun-
ing allow instant mode change with total recall of last setting and memories.
Front-panel selectable and adjustable inputs allow you to quickly setup and
adjust your DSP-599zx to wipe out noise and QRM like never before!
Here are a few more highlights among the many other operating features of
the DSP-599zx:
• Selectable Automatic Gain Control
• Configurable bypass control
• Two selectable input channels
• Two configurable output channels
• Six memories for instant recall of user-defined configurations
• Test instrument mode for analyzing signals and other equipment
Signal Flow
The DSP-599zx converts analog signals into digital signals before it routes
and processes them. The digital signal processor also controls the front panel
switches, encoders, LEDs, LCD display, and back panel inputs and outputs.
This figure is a greatly simplified block diagram of the DSP-599zx.
DSP
Circuit
PTT
I/O Data I/O
Front Panel Controls
and Display
Channel A
Input
Channel B
Input
DB-9
Connector
Speaker
Headphones
Line Out
Cha
n
B
Cha
n
A
599-013
Line Out
Headphones
Speaker
Timewave DSP 599zx
}
}

DSP-599zx Audio Noise Reduction Filter
March 6, 1997 1-3
Front Panel Controls
Overload
Normal
Off Gain
Low Pass
Bandwidth
High Pass
Center Freq
PTT
Timewave
Function
6
Shift
5
AGC
3
Bypass
Data
DSP-599zx
CW
Voice
Mode
1
Random
4
Tone
2
599-00
2
Setup
Test
Rcl/Store
Spkr/Chan
1. PTT/Overload LED
Red LED indicates a too high signal level into DSP-
599zx from receiver. When PTT line from transceiv-
er is connected, red LED on indicates PTT is activat-
ed.
2. Normal
Yellow LED indicates normal signal level into DSP-
599zx.
3. Mode switch
Press to change mode (Voice, CW, Data). Press
[Shift+Mode] to switch to Setup and Test modes.
4. Voice, CW, Data, Test, and Setup LEDs.
Indicate the selected mode of the DSP-599zx.
5. Spkr/Chan switch
Press [Shift] to toggle speaker on and off. Press
[Shift+ S
p
kr/Chan] to switch from Channel Ain-
put to Channel Binput.
6. Rcl/Store switch
To recall memory, press this key and then one of the
switches labeled 1 to 6. To store current settings in a
memory, press [Shift+Rcl/Store], then one of the
switches labeled 1 to 6.
7. Bypass Switch
Press to Bypass DSP filtering.
8. Tone Switch
Heterodyne elimination for Voice.
Marker Tone for CW and Data.Press [Shift+ Tone]
to adjust the aggressiveness of the tone notch filter or
to activate manually tuned notch filter.
9. Random switch
Used to turn on random noise reduction. Press
[Shift+Random] to adjust aggressiveness of the
noise reduction.
10. AGC switch
AGC on.
11. Shift switch
This blue switch shifts the function of the next switch
pressed to its function labeled in blue.
12. Function switch
This switch is used alone or in combination with the
shift key to access specialized functions.
13. High Pass/Center Freq Control
Tunes the high pass filter in the Voice mode.
Tunesthe bandpass filter center frequencyinCW and
Data mode.In most menu modes, this knob isrotated
to see menu choices. Pressing the knob selects the
choice.
14. Low Pass/Bandwidth Control
Tunes the low pass filter in the Voice mode.
Tunes the bandpass filter bandwidth for CW and
Data mode. Pressing knob will turn off temporary
settings.
15. Gain/Power On/Off
Turns power on and off, and volume control for
speaker output.
16. LCD Display
Backlit 2x16 alphanumeric display of mode, control,
and test settings and data.

1 – Introduction
1-4 March 6, 1997
Back Panel Connectors
Power
12-16 Vdc RS-232 Radio A Radio B PTT
Input
A
B
Audio
Input Line Ouput Speaker
Ouput Headphones
Timewave Technology Inc.
St. Paul, Minnesota USA.
599-005
1. Power In
12-16 Volts DC Use 5.5 mm/2.1 mm matching plug,
center positive.
2. RS-232
RS-232 compatible RTTY modem serial output for
computer interface. DB-9F connector. Refer to chap-
ter 2 for pin configuration.
3. Radio A
Alternative single 8 pin DIN connection for line out,
audio in, PTT out, PTT in, aux. digital in. Also con-
tains connections reserved for future options. Refer
to Chapter 2 for pin configuration.
4. Radio B
Alternative single 8 pin DIN connection for line out,
audio in, PTT out, PTT in, aux. digital in. Also con-
tains connections reserved for future options.
5. PTT Input A
PTT line from transceiver A PTT output. RCA
Phono connector.
6. PTT Input B
PTTlinefromtransceiverB PTT output.RCA Phono
connector.
7. Audio Input A
Audio input from radio speaker output - channel A.
RCA Phono connector.
8. Audio Input B
Audio input from radio speaker output - channel B.
RCA Phono connector.
9. Line Output A
Linelevel output to multimodedata controller - chan-
nel A. Gain control doesn’t vary this output. RCA
Phono connector.
10. Line Output B
Linelevel output to multimodedata controller - chan-
nel B. Gain control doesn’t vary this output. RCA
Phono connector.
11. Speaker Output A
4-8 ohm speaker output - channel A. RCA Phono
connector.
12. Speaker Output B
4-8 ohm speaker output - channel B. RCA Phono
connector.
13. Headphone Jack
Stereo headphone jack for 1/4” stereo plug.

DSP-599zx Audio Noise Reduction Filter
March 6, 1997 1-5
Features Common to All Modes
Random/Tone Noise Reduction
The noise reduction functions of the DSP-599zx operate by examining a
characteristic of signals and noise called correlation,and dynamically filter-
ing out the undesired signals and noise. The degree of correlation is relative.
Random noise such as white noise or static is uncorrelated. Speech is mod-
erately correlated. Repetitive or continuous noise such as a heterodyne is
highly correlated. The DSP-599zx measures correlation and filters out sig-
nals and noise that are outside its correlation thresholds. The amount of
noise reduction varies according to the correlation characteristics of the
noise. Typical noise reduction ranges from 5 dB to 20 dB for random noise
and up to 50 dB for heterodynes.
Adaptive Multi-tone and Manual Notch Filtering
(Tone noise reduction)
The DSP-599zx has both an automatic notch filter and a manually tuned fil-
ter. The automatic notch filter is an adaptive multi-tone filter that can re-
move multiple tones simultaneously. The automatic multi-tone filter
removes multiple heterodynes almost completely.
The [Center Freq] encoder on the front panel tunes the manual notch filter.
The manual notch filter is selectable and has a dual notch filter for data sig-
nals and a single notch filter for CW signals and heterodynes.
Dual Channel Operation
The DSP-599zx is a dual channel device with two sets of inputs and outputs.
The DSP circuit completely processes the selected channel, while signals on
the other channel pass through the DSP circuit without processing. Settings
for each channel are retained when switching between channels.
The two input channels allow you to connect either two separate radios or a
dual channel radio with two outputs to the DSP-599zx. You may configure
each channel to completely different operating modes. Selecting the oppo-
site channel returns the DSP-599zx to the previous settings on that channel.
This is very handy for two rig operations when setting one rig to monitor
CW and the other to monitor voice.
Function
6
Shift
5
AGC
3
Bypass
Setup
TestData
DSP-599zx
CW
Voice
Mode
Rcl/Store
Spkr/Chan
1
Random
4
Tone
2
599-006
High Pass
Center Freq
Time

1 – Introduction
1-6 March 6, 1997
Pressing [Shift+Chan] toggles between channels Aand B. The DSP-599zx
audio gain control simultaneously controls volume level of both channels.
Setup mode allows adjustment of the relative volume of the Achannel with
respect to the Bchannel.
Setup mode also allows you to configure the two output channels indepen-
dently. It is possible to configure the Line Out for each channel differently
from the external speaker and headphone outputs. This can be very conve-
nient when working in one of the Data modes.The Line Out can then be con-
nected to a multi-mode controller.
The DSP-599zx requires external speakers and/or headphones to hear the
audio signal. The DSP-599zx will accept either stereo or mono headphones
with a 1/4” plug. Stereo headphones are preferred over monaural head-
phones so that you monitor both output channels simultaneously.
Visible Memories
The DSP-599zx has six memories to store complete settings and con-figura-
tions. Pressing [Shift+Store+{#}] (# = 1 - 6) stores every setting and setup
configuration except theaudio gain control position. Pressing [Rcl+ {#}] in-
stantly recalls the complete configuration stored in the chosen memory. The
memory number is displayed along with the critical information on the LCD
and LEDs.
Automatic Gain Control
The DSP-599zx has switch-selectable automatic gaincontrol to optimize the
signal levels for best filter performance and to enhance listening by mini-
mizing audible signal level variation.
Function
6
Shift
5
AGC
3
Bypass
Setup
TestData
DSP-599zx
CW
Voice
Mode
Rcl/Store
Spkr/Chan
1
Random
4
Tone
2
599-032
High Pass
Center Freq
Time
Function
6
Shift
5
AGC
3
Bypass
Data
DSP-599zx
CW
Voice
Mode
1
Random
4
Tone
2
599-016
Setup
Test
Rcl/Store
Spkr/Chan
High Pass
Center Freq
Time

DSP-599zx Audio Noise Reduction Filter
March 6, 1997 1-7
Bypass Control
The DSP-599zx has bypass features that vary with the mode of operation.
In voice and CW modes, the bypass setting routes the signal through relay
contacts to completely bypass the electronic circuitry of the DSP-599zx.
Turning the power off to DSP-599zx uses the same relay bypass method. In
data mode, the bypass route is through the DSP processor. The amount of
signal delay through the bypass route is equal to the delay through the pro-
cessed signal route. The purpose of this delay equalization is to allow
switching between signal processing and bypass without breaking the hand-
shaking link of modes like PacTOR and G-TOR.
Bypass respects the status of the speaker switch. If the speaker is turned off,
bypass leaves it off. The speaker will always, however, come on when pow-
er is turned off on the DSP-599zx.
Operating Modes The DSP-599zx has three normal operating modes that operators will most
often use:
• Voice
•CW
• Data
Pressing [Mode] steps from Voice mode to CW mode to Data mode back to
Voice mode in a circular queue.
There are two more modes that operators will normally use during initial
configuration, installation, and troubleshooting,
•Test
• Setup
Pressing [Shift+Mode] once places the DSP-599zx in Test mode. Pressing
[Shift+Mode] again steps to Setup mode. Pressing [Mode] at any time
places the unit back in one of the normal operating modes again. When in a
menu or test instrument mode, pressing the middle knob will back you up
one level. Think of the middlebuttonin most cases as a cancel/clear button.
Function
6
Shift
5
AGC
3
Bypass
Data
DSP-599zx
CW
Voice
Mode
1
Random
4
Tone
2
599-061
Setup
Test
Rcl/Store
Spkr/Chan
High Pass
Center Freq
Time

1 – Introduction
1-8 March 6, 1997
Voice Mode
The Voice Mode digitally processes all analog voice signals for all modes
including SSB, AM, FM, and PM. Independently selectable processing tech-
niques include noise reduction, heterodyne elimination, tunable high-pass/
lowpass filtering, notch filtering and automatic gain control.
Highpass/Lowpass Filters
The DSP-599zx has highpass and lowpass filters that are independently tun-
able with front panel controls. The LCD display shows the corner frequen-
cies of the filters as they are tuned. There are many uses for the variable
combinations of highpass and lowpass filters that the DSP-599zx offers. In
a typical example of a voice mode application, highpass and lowpass filters
can improve a signal with a poor signal-to-noise ratio. The independent
highpass and lowpass filters remove the low and high audio frequency com-
ponents that do not contribute significantly to the speech intelligibility, thus
improving signal quality. Another common voice mode example is the im-
provement of a SSB signal corrupted by adjacent channel interference
(QRM). The steep skirts of the highpass and lowpass filters allow the oper-
ator to minimize or eliminate high side and low side interference indepen-
dently with minimal impact on the desired signal.
The DSP-599zx highpass filter adjustment rangeis from 100 to 1000 Hz and
the lowpass range is from 1000 to 5000 Hz. Although the DSP-599zx has
bandpass filters for CW and the most common data modes, the selectable
highpass and lowpass filter combinations also allow precise filtering for
modes such as wideshift RTTY.
Random Noise Reduction
The DSP-599zx random noise reduction has proven to be useful in reducing
a wide variety of noise types, including white noise, line noise and static
crashes. The amount of noise reduction varies according to the characteris-
tics of the noise. Typical noise reduction ranges from 5 dB to 20 dB. It is
possible to change the level of aggressiveness within a regular operating
mode without going into setup mode.
Function
6
Shift
5
AGC
3
Bypass
Setup
TestData
DSP-599zx
CW
Voice
Mode
Rcl/Store
Spkr/Chan
1
Random
4
Tone
2
599-006
High Pass
Center Freq
Time

DSP-599zx Audio Noise Reduction Filter
March 6, 1997 1-9
Adaptive Multi-tone and Manual Notch Filtering
(Tone noise reduction)
The DSP-599zx has both an automatic notch filter and a manually tuned fil-
ter. The automatic multi-tone filter removes multiple heterodynes almost
completely. The aggressiveness is adjustable.
The manual notch filter is selectable for either as a dual notch filter for data
signals and a narrow bandwidth filter for CW signals and heterodynes. The
center frequency of the filter is easily set. This filter can be used either to re-
move a single tone or to remove mark/space data tones.
CW Mode
The CW Mode digitally processes analog CW (Continuous Wave) signals
for Morse code reception. Independently selectable processing techniques
include noise reduction, tunable bandpass filtering, notch filtering and auto-
matic gain control.
Bandpass Filters
The DSP-599zx has a fully tunable bandpass filter for use in the CW mode.
The LCD display shows the center frequency and bandwidth of the filter as
the operator tunes with front panel controls. Narrow band signals like CW
and RTTY require a bandpass filter with steep skirts and linear phase re-
sponse. Linear phase response maximizes the usable signalingrate for a giv-
en bandwidth and minimizes ringing often heard on other extremely sharp
crystal and audio filters. The DSP-599zx CW filter has skirts so steep that a
signal literally falls off the edge of the passband as you tune through a CW
signal.
Bandwidths for the bandpass filter range from 10 Hz to 600 Hz, and center
frequencies range from 200 to 2095 Hz. The narrow filter bandwidths are
Function
6
Shift
5
AGC
3
Bypass
Data
DSP-599zx
CW
Voice
Mode
1
Random
4
Tone
2
599-027
Setup
Test
Rcl/Store
Spkr/Chan
High Pass
Center Freq
Timewave
Low Pass
Bandwidth
Function
6
Shift
5
AGC
3
Bypass
Data
DSP-599zx
CW
Voice
Mode
1
Random
4
Tone
2
599-007
Setup
Test
Rcl/Store
Spkr/Chan
High Pass
Center Freq
Time

1 – Introduction
1-10 March 6, 1997
usefulfor trying to dig out extremely weak signals from thenoise and QRM.
The narrow bandwidth is alsoan excellent way of tuning to a single CW sig-
nalin a crowdedband condition. The widerfilter bandwidth allows easy tun-
ing and listening to multiple CW signals simultaneously.
Random Noise Reduction
The DSP-599zx random noise reduction has proven to be useful in reducing
a wide variety of noise types, including white noise, line noise and static
crashes. The amount of noise reduction varies according to the characteris-
tics of the noise. Typical noise reduction ranges from 5 dB to 20 dB. In the
CW mode, random noise reduction is generally most effective in the wider
CW bandwidths (400-600 Hz).
Manual Notch Filtering
The DSP-599zx has a manually tuned notch filter. The [Center Freq] en-
coder on the front panel tunes the center frequency of the manual notch fil-
ter. The manual notch filter has an adjustable bandwidth allowing removal
of many types of signals such as data signals, CW signals and heterodynes.
Usually a narrow bandwidth filter is most effective for the greatest improve-
ment of a CW signal, but some operating conditions (i.e., a contest) dictate
a wide CW filter bandwidth. The manual notch can remove a single strong
annoying signal.
Marker Tone
Pressing [Tone] while in the CW operating mode inserts an audio marker
or spotting tone at the center frequency of the bandpass filter. Tuning the
bandpass filter center frequency changes marker tone center frequency.
Matching the marker tone frequency with the received signal allows switch-
ing in a narrow filter without losing the signal outside the passband of the
narrow filter. The level of marker tone is adjustable relative to the processed
receive signal.
CW Tone Pitch Shift
A feature unique to the DSP-599zx is the ability to easily shift the CW tone
pitch to another frequency. This feature works well with receivers that have
non-adjustable, relatively high pitch CW tone, since most hams prefer to lis-
ten to 400 - 600 Hz CW tones.
Function
6
Shift
5
AGC
3
Bypass
Data
DSP-599zx
CW
Voice
Mode
1
Random
4
Tone
2
599-014
Setup
Test
Rcl/Store
Spkr/Chan
High Pass
Center Freq
Timewave
Low Pass
Bandwidth