dsp9

Subject:  Timewave DSP-9 modification


I recently purchased a Timewave DSP-9 audio filter.  It's an amazing little
box.  The DSP-9 CW filters have RAZOR SHARP skirts.  Signals simply vanish
the moment they are outside the passband.  Awesome.

I had one gripe with the unit.  The 600 and 750 Hz CW filter center
frequencies the device was programmed with are too high for hard-core CW
DXing.  A call to Timewave revealed an "undocumented feature" which allows
the center filter frequencies to be shifted down to 400 & 500 Hz, a big
improvement.

(1)  Remove the DSP-9's rear panel.

(2)  Locate the three miniature sets of "prongs" (don't know what else to
call them) poking out the rear of the circuit board.

(3)  The #1 prongs come from the factory shorted.  Leave them alone.

(4)  Add a computer-style shorting strap to the #2 prongs.

(5)  Your DSP-9 now has selectable 400 & 500 Hz CW center frequencies.

Bill AA6TT