M248 Battery MOD w/update

Install a power supply PC board that allows the M248 to be powered by an external 12 volt battery pack.
The M248 update improves the DC power supplies used for the mic preamp and EQ chips.
Increases gain from 20dB to 30dB. Tweaks the mic preamp circuit resulting in better detail and clarity as well as lowering noise in the high frequencies.
Price includes ground shipping in the 48 states.