West Mountain Radio CLRdsp ClearSpeech User manual

www.westmountainradio.com
1020 Spring City Drive
Waukesha, WI 53186
262-522-6503
[email protected]
©2012 West Mountain Radio, All rights reserved. All trademarks are
the property of their respective owners.
CLRdsp ClearSpeech®
Noise Reducing Digital
Signal Processor

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West Mountain Radio Operating Manual
Thank you for choosing the CLRdsp ClearSpeech®Noise Reducing Digital
Signal Processor with communications grade loudspeaker. The noise reduction
circuit and audio amplier in CLRspkr is extremely effective in improving
communication clarity. Mobile and base operation is less fatiguing and much
more fun!
CLRdsp noise reduction is superb due to the Digital Signal Processor (DSP)
passing voice and CW sounds, while attenuating noise, such as atmospheric
noise, hum, hiss, whistles, and static. It effectively removes heterodynes,
ignition noise, lightening crashes, power line noise. The process is dynamic
and changes with the interference and the signal, but the effect is rewarding.
QSO’s are more fun without all the background noise. The DSP recognizes the
intermittent nature of CW and allows it to pass noise free.
CLRdsp may be mounted in any convenient location, such as under a station
speaker. It ts perfectly under the West Mountain Radio COMspkr. Included
are two (2) 6ft. cables with 1/8-inch stereo audio connectors for audio input and
external speaker output. Volume and DSP ltering levels may be adjusted by
use of the front panel controls. A headphone connector on the front may be
used with any stereo headphone set. The unit also includes a 6ft. power cable
with Powerpole connectors that will plug into a 13.8 volt supply.
Choosing a Mounting Location
The CLRdsp should be placed nearby for easy operation and close to the radio,
speaker, and power supply. The 6ft. cables can be lengthened with extensions.
This unit is not weather resistant and suggested to use in a dry place out of
direct sunlight.
Connections
Audio Input Jack:
Audio input is via the 1/8-inch stereo jack. Use the supplied 6ft. stereo cable to
plug into the headphone output or the external speaker output on the radio. If a
radio has a stereo output, the CLRdsp will only receive the left output.
The audio input is transformer coupled within the CLRdsp to reduce any “ground
loops”.
**NOTE for Stereo Cables: The CLRdsp is only one channel. The stereo jack
cable uses only the tip and ground. If using a mono plug into a stereo jack,
one channel gets shorted to ground and may damage the source. To prevent
problems, a stereo cable is supplied. A stereo jack will use only one channel,
but still works with a mono plug.

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West Mountain Radio Operating Manual
Speaker Output Jack:
Speaker output is via the 1/8-inch stereo socket. The tip is positive and the
sleeve is negative, which is not connected to Ground. Use one of the 6ft.
stereo cables provided to connect to the external speaker. Recommended
for a 4 or 8-ohm external speaker.
Headphone Jack:
The front panel headphone jack works with stereo headphones only.
Both left and right channels receive the same signal for equal reception
in both ears. The high level audio works ne with modern 8 to 600 ohm
headphones. Plugging in headphones will not silence the external speaker.
Power:
The CLRdsp comes with a 6ft. power cable. One end is a 2.1 mm power
plug (tip hot) and the other is a pair of Powerole connectors. RED is for
PLUS 13.8 VDC and BLACK is for Ground.
If using other connectors, just remove the Powerpoles and connect the
white striped wire to PLUS 13.8 VDC and the other wire to ground.
The CLRdsp is protected from a reverse polarity power connection.
A small 1-amp 12-volt, wall mount power supply (wall wart) may be used to
power the CLRdsp. The plug required is 5mm OD with a 2.1 mm pin, and
the pin is positive. West Mountain Radio carries an appropriate supply for
117 VAC.
Volume Control:
The desired volume level from the external speaker may be controlled with
the volume knob on the front of the CLRdsp unit. Headphone volume is
controlled with the volume control of the radio. NOTE: If using headphones
only, turn down the volume knob on the CLRdsp completely.
Operating
CLRdsp is easy to operate. The front panel “Filtering’ control allows continuous
DSP level adjustment. When turned fully counterclockwise, the DSP is bypassed.
When turned fully clockwise, maximum DSP ltering is realized. Maximum ltering
is rarely needed during use. A recommended setting is at the 10 - 12 o’clock
position for typical HF channel conditions.
If the incoming audio level is too high the CLIP LED will ash. Reduce the input
just below ashing. Clipping disrupts the noise reduction circuit.

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West Mountain Radio Operating Manual
Noise Reduction Performance
The noise reduction is dynamic and adaptive. It senses the random character of
the voice or CW and permits it to pass through. The repetitive nature of the noise
is sensed and reduced according to the patented algorithms. Take notice of the
DSP battling the difference between the voice and the noise when both are at
equal level and the noise is constantly varying.
When the signal is CW, its intermittent character is sensed and the CW is passed
through. The noise is attenuated. When the noise is steady, such as a heterodyne
from a 40 meter broadcast station (carrier whistle), it is attenuated greatly to over
50 dB or about 0.003 times the original value. If the noise is a varying siren, it is
greatly reduced as well, but not as much as a heterodyne.
Transient sounds are greatly reduced, especially if they are repetitious. The net
effect of the Digital Signal Processor is to reduce atmospheric noise, static, hiss,
ignition noise, power line noise, carriers, hum, and heterodynes, while passing
voice and CW signals.
The adaptive nature of the noise reduction is apparent by observing its convergent
time. A single audible tone will vanish in about 1 second. White noise diminishes
in 1 to 2 seconds. Typical car noise and emergency alarms take about 2 seconds
to reduce.
Power Amplier
CLRdsp contains a power amplier integrated circuit. It produces 7.5 watts RMS
maximum into an 8 ohm loudspeaker, when connected to a 13.8 volt DC source.
The voltage gain is 46 dB typically. The amplier has protection from a shorted
speaker.
ClearSpeech Adaptive Speech Filter
The ClearSpeech Adaptive Speech Filter is an algorithm designed to lter noise
from audio signals containing both speech and noise. It is implemented in a
circuit board containing DSP circuitry and a small audio power amplier.
Immunity from RF Interference
CLRdsp contains circuitry to reduce interference from the transmitted radio
signal. There are lters on all input wires, and decoupling capacitors at key points
throughout the electronics. There is a ferrite inductor in series with the positive
power lead.
Audio input is via a coupling transformer. The audio input ground is not connected
to the power return. This helps reduce any ground loops.

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West Mountain Radio Operating Manual
Specications
Enclosure Aluminum, powder coat painted
Dimensions 5.75 x 4.25 x 1.25 inches
Power Requirements 9 to 16 Vdc; 1.1A typical before onset
of clipping
Audio Input High impedance, 0.01 VAC
Voltage Gain 46 dB
Audio Output Power 11 watts RMS into 4 ohms @ 13.8 VDC
Maximum Audio Output Voltage 7.75 Vrms
Input Clipping Level 0.04 volts RMS
Noise Reduction Characteristics Adaptive, single tone greater than 50 dB
Powerpole® is a registered trademark of Anderson Power Products
FCC INFORMATION
For a Class B digital device or peripheral, the user instructions shall include
the following or similar statement, placed in a prominent location in the text of
the manual:
Note: This equipment has been tested and found to comply with the limits for
a class B digital device, pursuant to part 15 of the FCC Rules. These limits
are designed to provide reasonable protection again harmful interference in
a residential installation. This equipment generates, uses and can radiate
radio frequency energy, and if not installed and used in accordance with the
guarantee that interference will not occur in a particular installation. If this
equipment does cause harmful interference to radio or television reception,
which can be determined by turning the equipment off and on, the user is
encouraged to try to correct the interference by one or more of the following
measures:
•Reorient or relocate the receiving antenna
•Increase the separation between the equipment and receiver
•Connect the equipment into an outlet on a circuit different from that to
which the receiver is connected.
•Consult the dealer or an experienced radio/TV technician for help.
Modications not expressly approved by the manufacturer could void the user’s
authority to operated equipment under the FCC Rules.

CLRdsp Warranty
CLRdsp is warranted against failure due to defects in workmanship or materials for
one year after the date of purchase from West Mountain Radio. Warranty does not
cover damage caused by abuse, accident, misuse, improper or abnormal usage, failure
to follow instructions, improper installation, alteration, lightning, or other incidence of
excessive voltage or current. If failure occurs within this period, return the CLRdsp or
accessory to West Mountain Radio at your shipping expense. The device or accessory
will be repaired or replaced, at our option, without charge, and returned to you at our
shipping expense. Repaired or replaced items are warranted for the remainder of the
original warranty period. You will be charged for repair or replacement of the CLRdsp or
accessory made after the expiration of the warranty period.
West Mountain Radio shall have no liability or responsibility to customer or any other
person or entity with respect to any liability, loss, or damage caused directly or indirectly
by use or performance of the products or arising out of any breach of this warranty,
including, but not limited to, any damages resulting from inconvenience, loss of time,
data, property, revenue, or profit, or any indirect, special incidental, or consequential damages,
even if West Mountain Radio has been advised of such damages.
Except as provided herein, West Mountain Radio makes no express warranties and any
implied warranties, including fitness for a particular purpose, are limited in duration to
the stated duration provided herein.
www.westmountainradio.com
1020 Spring City Drive, Waukesha, WI 53186
tel [phone] fax [phone]