Linx ES Modules: AC coupling 2

[Leiterelec]

I had intended to send an analog message from a voice chip through a Linx RF module. The idea was to transit a continulous loop message for a wireless beacon. However, their manual mentions the need for AC coupling. Does AC coupling mean that the signal must be generated by an AC powered transmitter? Does this mean that I cannot simply connect the DC voice chip board to the ES module? If I must use an AC transmitter then my whole plan must be revised - all voice chips appear to be DC powered.

 

[pstuckey]

AC coupling just means use a dc block (capacitor).

Peter

 

[Comcokid]

To AC couple, connect the ground of the two modules together. However, the voice output of your chip needs to connect to the audio input of the Linx module through a capacitor. If a value is not indicated, I would try a 1uf to 10uF capacitor. Use an electrolytic capacitor with the + side of the capacitor towards the voice chip, or a non-polarized capacitor type will work as well. You can probably find the capacitor at Radio Shack, Fry's, or through a number of internet/mail order parts places.

 

[Leiterelec]

I'm most grateful for the two helpful replies. I grasp the concept of AC coupling meaning using a capacitor as a blocker. It appears that I also need to run a jumper between pins 4 and 9. I went through several books on RF and could not find an answer until I happened upon this website. Thanks again.