B
Bob F
Guest
I have been trying to get my Galaxy S9 to record FM radio programs.
NextRadio is the only app that I have gotten to work to receive FM using
the internal tuner, but it has no record capability.
I have the app Audio Recorder loaded, which works for a headphone/w
microphone well, but does not work with the Recording Source set to
internal audio with the NextRadio app, which I had hoped would work.
So, I am trying to make a cable from a 4 wire TRRS audio cable that can
plug into the phone, acting as the FM antenna, and feed reduced signal
from the audio outputs from the phone into the microphone signal input
to the phone.
I used a 29.5 inch length of the audio cable with the TRRS male plug at
one end, and built the following circuit at the other end, hoping the
would signal the phone that it has earphones and a microphone connected
to the phone so Audio Recorder can record from the back fed headphone
output.
https://source.android.com/docs/core/audio/latency/loopback
Unfortunately, this is not working. It seems the phone is not detecting
the signal coming in as an external mic, and picks up the intern phone
mic instead. My understanding is that the phone looks for the impedance
of a mic to make the switch, and it seem the resisters in the above
circuit is not causing that to happen.
If anyone has knowledge about what the phone expects to make the mic
switch, I can definitely use some help. A record app that can force
external mic switching could be a solution. A FM radio program that can
use internal audio or that has built in record function that will work
on the S9 could also be my solution.
NextRadio is the only app that I have gotten to work to receive FM using
the internal tuner, but it has no record capability.
I have the app Audio Recorder loaded, which works for a headphone/w
microphone well, but does not work with the Recording Source set to
internal audio with the NextRadio app, which I had hoped would work.
So, I am trying to make a cable from a 4 wire TRRS audio cable that can
plug into the phone, acting as the FM antenna, and feed reduced signal
from the audio outputs from the phone into the microphone signal input
to the phone.
I used a 29.5 inch length of the audio cable with the TRRS male plug at
one end, and built the following circuit at the other end, hoping the
would signal the phone that it has earphones and a microphone connected
to the phone so Audio Recorder can record from the back fed headphone
output.
https://source.android.com/docs/core/audio/latency/loopback
Unfortunately, this is not working. It seems the phone is not detecting
the signal coming in as an external mic, and picks up the intern phone
mic instead. My understanding is that the phone looks for the impedance
of a mic to make the switch, and it seem the resisters in the above
circuit is not causing that to happen.
If anyone has knowledge about what the phone expects to make the mic
switch, I can definitely use some help. A record app that can force
external mic switching could be a solution. A FM radio program that can
use internal audio or that has built in record function that will work
on the S9 could also be my solution.