Author Topic: Passive mixer question  (Read 2748 times)

SteveyD

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Passive mixer question
« on: June 10, 2012, 06:33:49 am »
Jan,

In the MicroRDS user manual;

Figure 5.2.1
Simple Passive Mixer.

Is the resistor value of 1K5 on the Audio/MPX signal for a mono audio input?

How would you handle a Stereo Audio input for this circuit?

Jan

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Re: Passive mixer question
« Reply #1 on: June 10, 2012, 12:32:59 pm »
For stereo audio use two inputs instead of one and place two 3k3 resistors. So there will be three inputs and three resistors total connected to the sum point.

Code: [Select]
Left  o--[===]---------\     2x 3k3
                        \
Right o--[===]-----------*---->
                        /
RDS   o--[===]---------/     15k

Of course you will broadcast in mono as there's no stereo encoder.