AKG C 28
Small diaphram condenser microphone.

Year introduced	1955
Year discontinued	unknown
Polar pattern	Cardioid (with CK 28 capsule) Omni with optional CK 26 capsule
Frequency range	30-30,000Hz
Sensitivity	10 mV/Pa
Impedance	200/50 Ohms
Weight	0.2 kg (7 oz)
Dimensions	26 x 174 mm (1 x 6.875 inches)
Material	Metal case
Features	Changeable capsules, extensions
Connector(s) used	Proprietary AKG 5-pin

Rare valve microphone that was made in three different versions, A and B, which use a 6072 valve, and C, which uses a Nuvistor. The A version uses an N12 PSU, whereas the B and C versions use an N28A PSU.