Phantom Power
"Audio Empire" wrote...
There is two more type of condensor mic which don't use DC at all:
Both types use a low voltage RF generated by a low-noise RF oscillator.
The mic capsule of a RF condensor mic is part of a resonant circuit
that modulates the frequency of the oscillator signal. Demodulation
yields a low-noise audio frequency signal with a very low source
impedance.
In the other type of RF condensor mic the capacitance of the mic
capsule is used to modulate the amplitude of the RF oscillator.
Norbert
These were somewhat common back in the 1940's and 1950's but are rare (if
not
outright non-existent) today.
I just bought a Rode NTG-3 shotgun mic which was just introduced
late last year. It is being favorably compared to several of the long-
established industry-standard shotgun mics. It uses the RF oscillator
design, so the circuit appears to be still going strong.
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