[time-nuts] Re: World's most accurate PC clock!
flarsen at sbcglobal.net
Mon Jul 4 01:55:14 EDT 2005
Or the 10.245 MHZ and 11.155 MHz crystals used for
converting 10.7 MHZ first IF to 455 KHZ second IF.
144.56 MHZ was used in Europe as a simplex channel
on 2 meters, as the 11.155 MHZ crystal was widely
(11.155 * 12) + 10.7 = 144.560
-- Flemming Larsen
--- Javier <javier at nebulosa.org> wrote:
> 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).
> Javier, EA1CRB
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