any ideas from more audio/videophile types on how I
might be able to get both the engine sound and the microphone sound
onto the tape?

There are a few ways, they all involve mixing at the source.

1: If you have stereo inputs, run the radio into the left channel, and
an audio mic into the right one. You can then mix them later. You may
need to experiment a bit with levels, as the radio is probably line
level and the mic is mic level. To do this you need a Y connector which
will separate the two channels. This is available at Radio Shack.

2: If you don't have stereo inputs, you could try using a regular mono
Y connector to yoke the two sources (mic and radio) into the same input.
You again will need to experiment with audio levels for the same
reasons as above. It's more critical because you can't isolate and mix
later, but it's easier once you've got the balance you want.

3: Get a mixer (cheap at radio Shack, but requires power). Run one
input into each channel, mix them down, and route the output of the
mixer into the camera.

4: Record at least one channel of audio separately with a digital
device. Video and digital will stay in sync for half an hour or more.
I'd reccomend recording the radio into the camera, and the ambient audio
in the digital device, but try both ways. You'll need to edit later to
combine the two channels.

5: Tape a microphone near the speaker, and monitor the audio with the
speaker (as well as the headphone). By putting the mic in different
positions, you can choose the balance you want. Run the mic directly
into the camera's audio input.

Jose
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