N4PY wrote:
>The Orion DSP filters are NOT audio DSP filters.
I beg to differ Carl...from page 52 of the Orion manual:
From A3, cable 11 brings the IF signal to
the 9-MHz IF (A4), where the hardware
noise blanker operates in a wideband
environment. Cables 14A and 14B route
the wideband IF signal through the
Sweep Amplifier (A13) to A7 for use in
ORION's band scope feature. Three
standard and three optional crystal filters
(normally selected by the BW control)
define the tuned signal bandwidth ahead
of DSP filtering. This stage provides
enough amplification to maintain the
receiver sensitivity despite unavoidable
filter losses. The amplified and bandlimited
signal feeds the IF Converter
(A5) via cable 16.
A5 provides conversion to the 2nd IF,
amplification, filtering, and conversion to
the 3rd IF for processing in the A7 Logic
board. Cable 18 carries the 14 kHz third
IF to the DSP in A7.
After digital signal processing in A7, the
recovered audio travels through the
Motherboard to the headphone jack on
A8 and to the EXT SPKR and AUX I/O
jacks on A12. From A12 wire cable 36
runs to the internal speaker.
DSP is done at the 14 kHz 3rd IF which is clearly audio.
Believe me, you could not afford DSP done at RF frequencies.
73, Bill W4ZV
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