slightly ot: battery driven microphone

[Steve Ridley]

The best choice would probably be a Bruel & Kjaer 
omnidirectional mic, perhaps the Model 4006, but these 
are very expensive.  I think they are now marketed by 
DPA (Danish Pro Audio).  B&K also make special 
measuring microphones, but these are extremely
expensive and require special powering.
 
The Earthworks omnidirectional mics are cheaper,
but still quite good.  A good Omnidirectional mic needs a
small capsule to avoid corrupting the polar response.  The
Earthworks has a smaller capsule than the B&K, but that 
means less signal, more gain and therefore more noise.

I suspect the B&K will be way too expensive, and maybe the 
Earthworks too, but you may be able to hire them.  Studio Hire
companies will usually rent microphones by the day or by the 
week.  They could probably rent you a phantom power box
too.

A phantom power supply is simple to build.  All you need is a
48v supply - it's not critical - five 9v batteries would be fine -
plus two 6K8 resistors and two capacitors.  The resistors go
from the +48v to the signal pins of the mic (pins 2 & 3), with the
caps stopping the 48v going into the mixing desk.  The negative
side of the 48v goes to screen (pin 1).


Steve Ridley