National WM-703

Matsushita aka National aka Panasonic

Japan is perhaps less well known for ribbon microphones as the USA, UK and Germany, but many excellent Japanese ribbon microphones were made in the post-WW2 era from the late 1940s through to the 1970s. 

The company that is now known as Panasonic was founded by Konosuke Matsushita, who was born on November 27, 1894 in Wasamura, Japan. He founded that Matshishita Electrical Company in 1917, making electrical sockets and bicycle lights. From 1923 onwards Matsushita traded under the brand 'National', and began manufacturing radio equipment in 1931. The Panasonic brand name appeared on some Matsushita products intended for export from 1955. Today most of their products are sold under the Panasonic brand. Several ribbon microphones appeared under the Matsushita and National brands, including the VM1 and WM series. Many of these mics are quirky with unusual aesthetic and technical features.

For our museum, we have grouped all of these together under the 'National' brand, even if they have a Matsushita badge.

https://en.wikipedia.org/wiki/Panasonic

From the Japanese language manual for the WM-703

Output Impedance: 600ohms ±30% Balanced (1,000 Hz)

Sensitivity: -75dB + 3 dB (0 dB = 1 v/μbar, 1,000 Hz)

Frequency Response: 50 to 10,000 Hz, deviation within 10 dB

Directivity: Approximately figure-8 bidirectional

Conducted Noise Level: 35 dB or less (equivalent to input sound pressure)

Height: 191 mm; Width: 66 mm; Depth: 40 mm

Weight without Cord, 650 g

Case: Chrome matte finish with dark gray baked finish

Yoke: Chrome matte finish

Stand Mounting Screw ⅜ x 16 thread or ½" pipe parallel thread.

(Translated from the manual)

It has a small, elegant design and uses a mechanically robust die-cast case. The WM-703 extends its frequency characteristics into the high range, and the output transformer uses a permalloy shielded case, so there is almost no inductive interference from AC magnetic fields.

Precautions for Use:

This microphone is equipped with a windproof device, but please pay particular attention to the following:

1. Because the velocity microphone uses very thin vibrating aluminum foil, do not use it in places subject to severe vibrations or strong winds.

2. Using the microphone near a sound source with very large amplitude (such as a bass drum) or with your mouth too close to the front of the microphone will reduce intelligibility.

3. Be careful not to connect this microphone to the input terminal of a carbon microphone or test its continuity with a tester, as current will flow and damage the microphone.

How to Use

When using this microphone, attach it to a floor or tabletop microphone stand.

The mounting screws are equipped with both W-⅜ x 16 and PS½ parallel threads, so it will fit any National stand. However, the WN-150, WN-103, and WN-101 are suitable for tabletop use, and the WN-403 and WN-401 are suitable for floor use.

Due to the characteristics of this velocity microphone, using it too close to your mouth may result in excessive low frequencies and reduced intelligibility. Therefore, keep it at least 20 cm away.

This microphone has a figure-8 bidirectional pattern in both the front and back. Therefore, it picks up sound from the front and back with equal strength, but it picks up almost no sound from 90-degree angles, whether above, below, left, or right. Therefore, always face it directly toward the sound source.