Thread: FM Bandwidth
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Old March 13th 11, 06:26 PM posted to rec.radio.amateur.homebrew
[email protected] disharp@swbell.net is offline
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First recorded activity by RadioBanter: Feb 2011
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Default FM Bandwidth

Most 2 meter rigs start clipping around 5 KC.




On Sat, 12 Mar 2011 13:36:47 -0600, Tim Wescott
wrote:

On Sat, 12 Mar 2011 18:48:14 +0000, Howard James wrote:

I'm building a 2 metre Rx with an IF of 10.7 MHz. It will be used for
FM. I have three crystal filters with the following bandwidths: 15 KHz;
+/- 6 KHz and +/- 3.75 KHz. Which one should I use? Thanks. Howard.


You mean 15kHz, 12kHz and 7.5kHz. You probably want 12kHz, unless your
channel spacing is really narrow.

FM bandwidth is calculated as 2 * (signal bandwidth + deviation), but for
the life of me I don't know what the deviation is supposed to be for
amateur narrow band FM!