John, I was unaware that the Pegasus used any user-installable conventional
crystal filters in the 455 KHz IF chain. There is a fixed bandwidth crystal
or ceramic "roofing filter" there, but it is much wider than 300 Hz and
changing it should have little or no effect upon the final IF bandpass in
the DSP section.
When you say that you measured the bandwidth of "my 300 Hz filter" is that
measurement based upon the DSP filter selection of "300 Hz?"
If the -6 db points of the 300 Hz DSP filter are such that the bandwidth is
800-1000 Hz, then it sounds to me that something is drastically wrong with
Sorry for any confusion, but this one has me stumped . . .
72/73/oo, George W5YR - the Yellow Rose of Texas
Fairview, TX 30 mi NE of Dallas in Collin county EM13qe
Amateur Radio W5YR, in the 56th year and it just keeps getting better!
QRP-L 1373 NETXQRP 6 SOC 262 COG 8 FPQRP 404 TEN-X 11771
Icom IC-756PRO #02121 Kachina #91900556 IC-765 #02437
All outgoing email virus-checked by Norton Anti-Virus 2002
John Peregord wrote:
> Has anybody experimented or attempted improving the IF filtering scheme of
> the Pegasus? I was wondering if it would be possible to make a modification
> similiar to what had been done to the TS-870 by some hams to improve
> selectivity? Could I substitute/modify the 455khz IF filter with something
> commericially available on the market. My 300hz filter on the Pegasus is
> more like 800-1000hz....Is the Jupiter the same?
> This rig has been one of my best rigs considering the band for buck ratio.
> I'd just like to tinker if at all possible since this list is always full of
> great ideas and information.