Ballistic measurement systems: Measuring proximity tubes with MENA (1976)

 

Measuring proximity tubes with MENA (1976)

 
The Royal Netherlands Army uses projectiles with proximity tubes. The performance of these tubes needs to be verified by the Commission of Trials (CvP) by selecting random samples per batch. Proximity tubes are detonators mounted on projectiles that initiate the explosive content when nearing the target. To check the proper functioning of the proximity tubes mounted on projectiles in the flight during such verification tests, LEOK has developed a “MEasurement device NAbijheidsbuizen” (= MENA). MENA was commissioned by the CvP in 1976. MENA is a special radio receiver that receives and registers the transmitted signal from a proximity tube during the projectile’s flight.

 

MEasurement device NAbijheidsbuizen (MENA): The shot started the measurement. With a RF-antenna, the projectile behaviour is followed. The detonation was measured with an infrared detector.
MEasurement device NAbijheidsbuizen (MENA): The shot started the measurement. With an RF antenna, the projectile behaviour is followed. The detonation was measured with an infrared detector.

MENA is used in shooting tests with proximity tubes in projectiles against land and air targets. The MENA searches for the signal transmitted by the proximity tube, tunes the receiver to the frequency thereof, records the modulation of the transmitted signal and records key moments of the projectile’s flight such as switch-on time and detonation moment of the projectile. This detonation is also detected by an infrared detector. The combined records allow for determining whether the proximity tube functions according to the specifications.

MENA (Measurement device proximity tubes)
MENA (Measurement device proximity tubes)

 

MENA coherent transmitter chain 30 kHz - peak power amplifier
MENA coherent transmitter chain 30 kHz – peak power amplifier

 

The RF-antenna of MENA
The RF-antenna of MENA

 

MENA has been used for the development of the Philips USFA (Ultrasonic FActory) New Proximity Tube 169 (NINA) for high-explosive shells of 120 mm and larger
MENA has been used for the development of the Philips USFA (UltraSonic FActory) Proximity Tube 169, called NINA (Dutch abbreviation) for high-explosive shells of 120 mm and larger