The RCA Type 88-A
pressure microphone (1938)
Microphone photos courtesy of Dennis Schrank
The Type 88-A Microphone is of the pressure-actuated type. The moving system consists of a thin molded diaphragm to which an annular coil assembly is attached. Coupled to the diaphragm is an acoustic circuit so proportioned that the diaphragm velocity will remain essentially constant for a constant sound pressure over the frequency range of 60–10,000 cycles. The coil is placed in the air gap of a magnetic structure and the ends connected to a transformer which provides output impedances of 50 or 250 ohms.
This microphone is styled and finished in either black and chrome, or umber gray and satin chrome to present a pleasing appearance. A ball and socket joint with a thumbscrew clamp permits operation in either a vertical or horizontal position.
The Type 88-A is the ideal microphone for general remote pickup use. It has been specially designed to provide small size, light weight, good frequency response and relative freedom from the effects of wind and moisture. In spite of its light weight and small size, it is extremely rugged and well-suited to stand the hard usage to which a remote microphone is put. The characteristics of the 88-A also make it adaptable for many types of audio use where a non-directional microphone is desired.
- Good frequency response.
- Light weight.
- Small size.
- Rugged construction.
- Low cost.
- Minimum effects from wind and moisture.
- High output providing unusually good signal-to-noise ratio.
- Adaptable for use with any stand or may be carried in the hand for street interview programs.
- Output cord protected by spring.
Reproduced from p. 15 of an RCA catalog, date unknown.
That’s Bob Hope on the right, using an RCA Type 88-A.