MDS 21 C - Absorbing Clamp


MDS 21 C - Absorbing Clamp


  • MDS 21 C-Absorbing Clamp
  • MDS 21 C-Absorbing Clamp_


The Absorbing Clamp MDS 21 C was designed to measure the disturbance power according to CISPR 16-2-2 in the frequency range 30-1000 MHz, it complies to the technical requirements of CISPR 16-1-3. The measurement of disturbance power was introduced in 1969 to the CISPR standardisation. Many fundamental investigations about the clamp construction and the disturbance measurement method itself have been done by the swiss PTT under the leadership of J. Meyer de Stadelhofen, whose initials are still visible in the name of the clamp.


The absorbing clamps basically consists of four functional units:


• RF-current transformer to pick up the measurand. Its position is marked with “CRP” (clamp reference point), which must face towards the EuT

• Absorber chain composed of split, precision grinded ferrite rings to provide a defined RF-termination to the EuT’s line under test and to decouple the mains influence

• Sheath wave supressors to improve reproducability (not visible, located in the lower housing)

• Plastic housing, convenient to open with wheels in roller bearings for easy movement



The use of an external 6 dB attenuator is recommended to improve the impedance matching to the 50 Ω system. In conjunction with a right angle adapter the coaxial cable can be guided perpendicular to the clamp body.


The MDS 21 C complies to all requirements of CISPR 16-1-3 and will be delivered including an individual calibration of the clamp factor CF.

Nominal Frequency Range:  30 ... 1000 MHz
Nominal Impedance:  50 Ω
Insertion Loss (nominal):  17 dB
Decoupling DR:  >21 dB
Decoupling DF:  >30 dB
Max. Current:  30 A
Max. RF-Input Power:

 20 W

Max. Cable Diameter:  17 mm
Connector:  N-female
Length x Width x Height:  645 x 66 (110) x 102 mm
Track:  58 mm
Ground Clearance:  8 mm
Wheel Width:  7 mm
Weight:  5.8 kg
Optional Accessories:

 6 dB N-Attenuator DGA 9552 N
 Angle Adapter N-f N-m
 Coaxial Cable RG 223/U (5 m)


pdficon small Datasheet MDS 21 C