I have a pair of very old (around about 1990) Altai omnidirectional microphones. Rather than throw them away, I wondered if I could use them with my PCM-10 in conditions where I would not want to risk anything more expensive. I have, in the past, made some quite successful recordings with them in conjunction with my old cassette deck, including some recordings of organ music. I would like to use them for recording ambient sounds. They do not work at all well with my Fostex FR2LE as the signal is far too weak. They are electret condensers, AA battery powered and their impedance is 600 ohms and their sensitivity is -65dB +/-3 dB at 1000Hz (details from the box).
The major advantage over the built in microphones would be, as I see it, the ability to gain better separation than with the built in microphones.
Any advice would be greatly appreciated.