I found a nice crystal frequency on eBay : 10.6875 MHz
Yes, 10700 - 12.5 kHz.
Combined with a 15 kHz wide 10.7 MHz FM filter and a direct conversion receiver this should make a 10.7 MHz spectrum scope with 15 kHz bandwidth, so :
10.7MHz signal from R7000 or similar receiver -->
possibly a preamplifier, in any case some termination for the filter -->
10.7MHz FM filter for 25kHz channel spacing (BW = 15 kHz) and 2nd termination -->
DC-mixer with oscillator frequency of 10687.5 kHz (possibly pulled up to 10690 kHz) -->
AF amplifier -->
output to PC running spectrumLab
Looks like yet another 'little' project.
should be good for looking at satellite transponders with (not too wideband) digital signals, and some Doppler tracking at the lower satellite frequencies.
KE5HPY's Altoids Direct-Conversion Receiver for 40 Meters
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Click on the image for a much clearer view.
*It is a thing of beauty. You can see all four stages in there. There is
the Bandpass Filter in the upper l...
2 hours ago
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