BeoMic BM5 Microphone
Manufactured: 1961 - unknown
Beomic 5 (150 ohms) mono/stereo ribbon model was a pressure gradient full range microphone with a perfect figure-eight pattern.
Features: No resonance peaks. Extremely smooth response. Bi-directional, no side pickup. No frequency discrimination front to back. High efficiency mu-metal transformer placed in microphone housing. Easy to convert from mono- to stereo-microphone. Steel housing to reduce hum sensitivity. Switches for close Talk (T) / Music (M) conditions and for phase reversing and muting.
The miniature non-corrosive duraluminium ribbon was only 0.0001" -thick and its weight only 1.3 mg. This negligible mass prevented any resonance within the audio range. Shock- and blast-proof. Ball swivel for tilting into any position.
BeoMic BM5 Microphone Product Specifications
Response Frequency Characteristic: "M" (Music) Position: from 20 to 13,000 c/s +/- 3 dB. "T" (Close talk) Position (8-16"): rolled off below 1000 c/s at 100 c/s; +/- 10 dB
Open Circuit Voltage Level: - 87 dB. OdB =1 Volt per Microbar
RTMA Microphone Rating Gm: (sensitivity): - 159 dB. RTMA Standard SE - 105
Hum Sensitivity (RTMA) Gh -153 dB
Output Impedance: Nominal at 1000 c/s: 150 Ohms
Rating Impedance: 150 Ohms
Size: 10 3/8" x 1 3/16"
Weight: 15 ozs. approx
Cable: Supplied with 20 feet 4-core over all screened.
Transformer, type 9398 - JS for matching BM5 to a high impedance input of a stereo amplifier available on special request. Mounting: Conical Friction Socket to 5/8" x 27 thread
Specifications: Dimensions 263mm high, 27mm diameter
Hum sensitivity -146 dB
Impedance 200 ohms
Response 30-13000 c/s +/- 2,5 dB
Sensitivity M position,85 dB below 1V/µbar
T position: 4 dB lower
Created: 24th February 2007
Modified: 24th February 2007