Timewave DSP-9+, Operating Manual

Page 1: ...DSP 9 Audio Noise Reduction Filter Operating Manual Version 3 0A Timewave Technology Inc ...

Page 2: ...2 2 Specification 4 3 Installation 5 4 Operation 7 5 Troubleshooting 13 6 Warranty 16 7 Electromagnetic Interference 17 8 Schematic Diagram 17 9 Appendix Connections 20 Copyright 1994 1995 Timewave Technology Inc St Paul MN USA 612 452 5939 Rev 3 0A ...

Page 3: ...mode example is the improvement of a SSB signal corrupted by adjacent channel interference QRM The steep skirts of the bandpass filters allow the interference to be eliminated with minimal effect on the desired signal In the voice mode two front panel push buttons select one of three voice bandpass filter bandwidths from two sets of filters An internal jumper behind the back panel selects the filt...

Page 4: ...DSP 9 The precise clean tones from the RTTY AFSK remodulator can feed any analog multimode controller or TU via the DSP 9 audio output Many analog RTTY demodulators have difficulty with noisy signals of varying amplitude but virtually all of them can adequately demodulate the precise DSP AFSK generator output The RTTY push button selects either the remodulator or the RTTY filters only Automatic Ga...

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Page 6: ...e internal supplies Radio Shack 273 1653 12 V d c 1 Ampere plug in wall supply use the green tipped adapter supplied with the Radio Shack unit Switching power supplies are generally not recommended Connecting Cables Shielded coaxial cables with RCA phono connectors should be used to minimize the possibility of RF interference to the DSP 9 Timewave recommends coaxial video cables with metal adapter...

Page 7: ...audio power amplifier and may damage the DSP 9 The DSP 9 speaker output is muted when a headphone plug is inserted 2 The Speaker Output RCA phono jack on the rear panel of the DSP 9 provides adequate output to drive a 4 or 8 Ohm speaker The front panel audio gain control adjusts the audio level from this output The maximum output power is approximately 2 5 watts into a 4 Ohm speaker or 1 6 watts i...

Page 8: ... functions To maintain the integrity of the EMI prevention measures in this unit it is important to replace all hardware when the unit is reassembled after opening the housing This includes the star washers around the audio input line output and PTTI back panel jacks the ground lugs at the sides of the PC board and all the panel screws 4 Operation Introduction One knob and seven push button switch...

Page 9: ... in the voice mode Voice AGC The AGC automatic gain control can add up to 36 dB extra gain for weak signals and can control the variation in levels of stronger signals Depress the AGC push button to turn on the AGC Use the AGC whenever it enhances the readability of a signal Sometimes the AGC appears to increase the noise level because of the additional gain of the AGC This is normal when signals ...

Page 10: ... signals are weak and may enhance readability in spite of the higher audible noise CW Bypass Mode Depressing the Bypass push button places the DSP 9 into a bypass mode In this mode a relay connects the audio input jack of the DSP 9 directly to the speaker and headphone output jacks The relay also connects the audio input jack of the DSP 9 to the line output jack via a 6 dB attenuator The Bypass mo...

Page 11: ...dulator first press in the RTTY push button to select the RTTY filter Then press the RTTY push button rapidly twice double click to enable the remodulator Leave the button pressed in after you have selected the remodulator To switch the remodulator off release the RTTY push button for one second or more The remodulator mode is easily recognized by a lack of any receiver background noise only the p...

Page 12: ... bypass relay and forces the DSP 9 into the relay bypass mode In this mode a relay connects the audio input jack of the DSP 9 directly to the speaker and headphone output jacks The relay also connects the audio input jack of the DSP 9 to the line output jack via a 6 dB attenuator ...

Page 13: ...ilters Center Frequency x x x on on off x x 500 600 Hz CW Filters Center Frequency x x x off off on x x 500 800 Hz CW Filters Center Frequency x x x on off on x x 600 800 Hz CW Filters Center Frequency Collins x x x off on on x x 1350 1500 Hz Not used x x x on on on x x Data Filters Mark Space Frequency x x x x x x off off 2125 2295 Hz 2110 2310 Hz Data Filters Mark Space Frequency x x x x x x on ...

Page 14: ... Mode switch is released 7 After the Mode switch is released the Voice LED lights indicating the start of the front panel push button switch test 8 Depress any push button except the Mode push button The DSP 9 will produce a 500 Hz tone 9 Depress a second push button The tone will change to a 2 kHz 10 If the audio circuitry is operating correctly the normal LED will be on and the Overload LED will...

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Page 16: ...udio output 1 Check power connection to DSP 9 2 Increase audio input level with receiver audio output level control until the Normal LED flashes 3 Turn front panel audio level control clockwise 4 Bypass the DSP 9 by turning it off Verify the audio level out of the radio by listening to the speaker If nothing is heard plug a set of stereo headphones into the front panel headphone jack If audio is h...

Page 17: ...ftware media or firmware which do not execute their programming instructions due to such defects Timewave does not warrant that operation of the software firmware or hardware shall be uninterrupted or error free The warranty period for each product is one year from date of shipment Limitation of Warranty The foregoing warranty shall not apply to defects resulting from 1 Improper or inadequate main...

Page 18: ...ntial installation This equipment generates uses and can radiate radio frequency energy and if not installed and used in accordance with the instructions may cause harmful interference to radio communications However there is no guarantee that interference will not occur in a particular installation If this equipment does cause harmful interference to radio or television which can be determined by...

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