Hello
all.
?
I have successfully
converted a SoftRock40 for use on 30M. Two capacitors need to be changed from
their original values, and a new oscillator crystal installed. Capacitors C6 and
C7 are changed from their original 100pF to 33pF. The crystal is changed from
its original 28.224 to 40.500 Mhz. The original crystal still works with the new
capacitor values (in?two units here). (I had tried this before, and didn't
think it worked, but my experiment was flawed. It is working now.)
?
By using a
machined-pin socket (or similar) for the crystal, band change is as easy as
swapping the crystal. A switch could also be wired in to select different
crystals. The receiver input band pass filter is wide enough to allow good
operation on 30M. When using the PowerSDR software, just go to Setup, and select
the SoftRock tab. Uncheck "Fixed HW Osc" and enter 10.125 in the Freq box. Then,
recheck the "Fixed HW Osc" box. That's it. PowerSDR will now display the correct
frequencies. Please note that these crystals are fundamental mode, HC-49 size
crystals, 100 ppm. The actual center freq on 30M will be +/- 1Khz or so. A
slight tweaking of the image reject settings may be needed for best performance
when changing bands.
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I have available a
quantity of the 40.500 Mhz crystals required. These allow nearly full coverage
of the Amateur 30M band with the SoftRock receiver. As I announced earlier, I am
making these available to all. The price for US delivery is $2.00 for one
crystal, $1.50 each for quantities of two or more. For foreign addresses
(including Canada) the price is $2.50 for one, $2.00 each for two and up. You
may send payment via PayPal?to bruce.beford@... I will fill
orders on a first-come, first served basis.
?
Any questions? Email
me direct, and I'll answer as best I can.
?
73,
Bruce
N1RX
