Original Message -----
Subject: [softrock40] Crystals in Softrock LTE combined kit
I really don't understand what is happening with the crystals for 20 meters operation. I understand that the counter needs a frequency that is four times that of the received signal to produce the two out of phase signals needed to produce the I an Q outputs.and I read that sampling is done at the 3rd overtone. Without a scope or spectrum analyzer I am having trouble trying to picture what the freq. is at the detector produced by the counter.
The crystal supplied for 20 Meters is 18.73 megahertz.
Is the crystal operating at the third overtone to create the 56 Mhz signal or is something else going on? I think I better buy a scope to really see what is happening.
A scope will not help:)
and other messages referring to "Subharmonic"
73 Alan G4ZFQ
