Re: CS-Series IF


Adam Rong
 

John,

In old days, when SSB radio is homemade, 9MHz IF is used because 5.0-5.5MHz VFO can be used for both 20 meter and 80 meter bands. However, 9MHz crystal is not generally available, so nearby frequency crystals can be chosen.

Thanks,
Adam


On Oct 21, 2017 2:10 AM, landrjoh@... [CHINA_QRP] wrote:
 

Adam,


The CS-Series is a great platform for learning and experimenting by changing a few components at a time just to see what effect it has.


So I'm curious why 8.4672 MHz was chosen as the IF in the CS-Series transceiver?


Could another frequency in the 8-10 MHz range be safely substituted for experimental purposes?  I do realize this would require completely recalculating and rebuilding the crystal ladder filter, replacing the crystal in the IF amp, and also altering the Arduino software.


Thank you,


John

AA7US

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