I will share my few bits of worked experience. But it may seem obvious.
I'd say to go "100% SDR". In other words a simple front and that pushes as much of the functionality into software as possible. The carrier is only 60K. That is low enough that one can directly digitize the RF using an ADC that samples at only 192K/sec.
Not necesarilly. I received 77.5kHz very well in first sampling mirror, sampling using ADS7813 16bit ADC @44ksps, yielding carrier at 10.5kHz in discrete-time domain.
192K/Sec is a common sample rte for high-end audio and you can buy a 24-bit dual channel interface for under $200.
Beware, there are lots of sigma-delta ADCs for this purpose and I am in doubt whether they could perform better than less-bits SAR ADC.
So I'd use an antenna (the best would be a shielded loop with many turns of wire but ferrite "loop stick" could work) Follow that be an RF amp and very narrow filter and then the above 24-bit 192K ADC.
I must object a little bit against "RF" and "very narrow" -- I have used very sloooooooow amplifiers (they were in a shack, original purpose DC measurement up to some 100s of kHz) and nothing narrow (or even tuned) -- except the ferrite rod itself. The rest were 2 ICs (amp & ADC) and simple RC network.
Worked very well, including few centimeters from laptop's CCFL inverter. Best regards, Marek _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
