Narrowband FM used in land mobile radio and amateur radio usually has
25, 20 or 12.5 KHz channel spacing. 10.24MHz was mostly used in CB
radios with a MC145106 or similar PLL IC, and with a double purpose: to
obtain a 5KHz PLL reference and also as the 2nd local oscillator to
convert 10.7MHz first IF to 460KHz second IF.
This reminds me another widely used crystal frequency for the list:
12.8MHz is used in radio transceivers with 25 and 12.5KHz channel
spacing, since 12.5KHz PLL reference is 12.8MHz / 1024 (and also another
discrepances: 60.005 would be 60KHz with a 5Hz IF, no 5KHz, and also
77.503 would be 77.5KHz with 3Hz IF, no 3KHz).
Regards,
Javier, EA1CRB
W. D. wrote:
At 19:09 7/3/2005, David Forbes, wrote:
Many older narrowband FM radio synthesizers using the MC145152 PLL
chip use 10.240 MHz to give 10 KHz channel spacing with its
binary-only R divider.
Hmmm. I thought FM had 200 Khz spacing, and AM had 10 Khz.
Start Here to Find It Fast!™ -> http://www.US-Webmasters.com/best-start-page/
$8.77 Domain Names -> http://domains.us-webmasters.com/
_______________________________________________
time-nuts mailing list
[email protected]
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
_______________________________________________
time-nuts mailing list
[email protected]
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
