In a message dated 5/16/99 8:12:08 PM Eastern Daylight Time,
pinskeep@iglou.com writes:
<< SELECTIVITY: 34 filters built-in; 300 Hz, 330 Hz, 375-750 Hz in
75 Hz increments, 900-3000 Hz in 150 Hz increments, 3.3-6.0 kHz in 300
Hz increments, 8.0 kHz. All 1.5:1 shape factor or better.
DYNAMIC RANGE: 90 dB @ 3 kHz bandwidth at 50 kHz spacing >>
I missed Dayton and Pegasus this year, but I wonder:
Is this DSP "selectivity" as "good" as TS870 was?
Will strong station 5 kHz away paralyze the radio like TS870 was?
TS870 with its DSP "filters" would choke with strong signals near by, until I
installed decent InRad 2.1 kHz filters instead of "regular" Kenwood 8MHz
crystal filter and ceramic joke "filter" at 455 kHz. Completely different
radio, even DSP now works much better.
No mention in the Pegasus specs what the (any crystal) real filters are?
I think this specification at 50 kHz spacing is old-fashioned (makes even DSP
"filters" look good). We need to know how close lets say 20 over S9 signal
can get to our weak S2 signal RX frequency, without rocking (wrecking) the
reception.
There is no substitute for good rock based filters, as close to the antenna
as possible. The DSP "filters" close to the speaker look good on spec sheets,
but are useless for discrimination next to strong signals on the band. If the
RX stages get overloaded and crossmodulated with strong signals, DSP is
confused and useless later on in the RX food chain.
And for real ham contest operation I NEED the knobs, more - the better! Keep
the menus for restaurants. Now if I only could turn the knobs on the computer
screen with my hand..... naaah, that would fuzzy up the display from sweaty
fingers.
73 Yuri, K3BU
VA1A in WPX CW 160m May 29-30
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