Elecraft • www.elecraft.com • 831-662-8345
E
LECRAFT
KDSP2
INTERNAL DSP FILTER and REAL-TIME CLOCK
Assembly and Operating Instructions
Revision A.1, June, 2003.
Copyright © 2003, Elecraft; All Rights Reserved
Introduction
The KDSP2 DSP Filter is designed specifically for internal operation with an Elecraft K2 transceiver.
For the CW operator
The KDSP2 provides filter bandwidths from 50 to 800 Hz, with center frequencies from 400 Hz to 1,300
Hz, to help eliminate nearby interfering signals. The filters may be easily adjusted from the front panel,
and up to four (4) filters may be selected by the AFIL button.
Noise reduction helps reduce QRN, and may be used with any of the CW filters.
For the SSB operator
A tunable bandpass filter is settable from the front panel, offering low-frequency cutoff (high pass filter
function) from a few tens of Hz to 600 Hz, and a high frequency cutoff (low pass filter function) from 1.6
kHz to 3.0 kHz.
In addition to the tunable bandpass filter, an automatic notch filter quickly locates and suppresses
interfering carriers, such as those caused by other stations tuning up nearby. Noise reduction is also
available and may be used in conjunction with the bandpass and autonotch filters.
For the Data operator
Bandpass filters tuned for common HF data modes, such as RTTY, Packet and PSK31 are provided.
Center frequencies vary from 1 to 2.5 kHz, and widths from 50 Hz to 1 kHz.
Noise reduction and notch filters are not available in data modes as phase distortion may result in poor
copy on an otherwise clean-sounding signal.
Convenience Features
All filters are adjustable from the front panel. Up to four (4) filters per mode (CW/SSB/DATA) may be
memorized. The filters are then selected by simply pressing the AFIL button. A front-panel selectable
bypass mode is available which significantly reduces current consumption.
