Aiwa VM-17 (RV-1A)

This microphone was known as either an Aiwa VM-17 or rebranded as an NHK RV-1A as for national broadcast use. It was Japan's first variable-directivity ribbon microphone and was developed in collaboration with NHK.

A distinctive feature is the minimal change in frequency response and sensitivity when switching directivity.

Praised as a versatile microphone, it became a standard model for broadcasting for many years.

As a national broadcaster, NHK has a responsibility to maintain an equal and neutral stance, and is not allowed to mention the names of specific companies or display them on screen in a way that could constitute corporate advertising. Naturally, the Aiwa logo was removed and replaced with the NHK logo.

From Wireless World, April 1968

"The Japanese broadcasting authority's (NHK) research laboratories have brought out the NHK RV1A, an instrument which is a modern version of an old R.C.A. device. It incorporates a ribbon, the rear of which is partially covered by a tube leading to an acoustic labyrinth. Omni-directional, figure -of-eight and cardioid characteristics are available. Although much smaller than the old R.C.A. device, it is still fairly large by present-day standards, but on the other hand the performance is stated to be of very high quality.

About Aiwa

Aiwa started producing microphones from the early 1950s. By 1956, the company was designated as a technical guidance factory by the NHK Broadcasting Technology Research Laboratories, reflecting the technical quality of it's products. Throughout the following decades, Aiwa produced various styles of microphones with their ribbon microphones offerings aimed at professional and broadcasting use. 

Frequency response: 50 - 15,000Hz ±3dB

Impedance: 600Ω ± 20%

Sensitivity: -74bB ± 2dB

Released: 1957

Price (then): ¥93,600

Mounting Thread: PT1/2 Pipe Thread with W5/16 Adapter

Directivity: Variable Directivity (Cardioid/Fig-8/Omni)

Inductive Noise Level: -16dB

Dimensions (mm): 60Φ x 198

Weight (g): 1.7kg (2m cord, including outlet)

Cord: 2m with 21P3B plug

HPF: Built-in 5-stage inductor switch for low-frequency attenuation

About the VM-17 at the Japanese Aiwa 5Volt archive

A nice example of a RV-1A at Soviet America Audio Systems, including a sound recording. According to SAAS, 'only' 600 to 700 of these microphones were built.