|Toshiba type H ribbon mic – looks like a BK5|
The ‘Model H’ is no exception, being almost identical to the RCA BK5 cardioid ribbon in both looks and function. The small format ribbon sits between powerful magnets, in front of an acoustic chamber or labyrinth that takes up the middle segment of the microphone
|Rotating the base of the mic implements a high pass inductive filter.|
In fact it seems slightly better engineered than the BK5, with a 5 position high pass filter switch that is actuated by rotating the dial at the very bottom of the microphone.
|Toshiba type H ribbon|
There is some additional electrical screening around the ribbon, but less acoustic baffling in front of it, which may be to give a more ‘open’ sound. In practice the ribbon is more prone to being stretched by air blasts than the RCA model.