[aprssig] GM-300 speaker output

[Steve Noskowicz]

  http://k9dci.home.comcast.net/


--- On Tue, 9/29/09, Dave Baxter <dave at uk-ar.co.uk> wrote:

> Use a low ohm resistor in place of
> the speaker to keep it's OP stage
> happy, 

  Yes, but....

> and a simple differential input OP-AMP stage to get
> the audio off the resistor.

If it is true differenial (has to be), you only need to couple off one side.  However, the disc output should be better (with proper audio shaping as appropriate - aka de-emphasis or not)

73, Steve , K9DCI