Schwarzbeck VPMP 9241 Vertical Passive Monopole Antenna

The vertical passive monopole consists of a flat alumium base plate and a milled aluminium housing, which has two N-connectors at the sides and an element clamping fixture on top. The element clamping fixture with a nominal diameter of 10 mm accepts the vertical rod of 0.5 m length, which is included in standard delivery.

A typical application is the validation of ALSE (Absorber lined shielded enclosure) as proposed by CISPR 25 Ed. 4. An optional top loading disc (TLD 9241) is also available. Instead of the 0.5 m rod nearly all element types of the Schwarzbeck product range can be used, e.g. biconical elements BBA 9106, BBAL 9136, BBAK 9137, BBVK 9138, or collapsible elements FBAL 9177, FBAB 9178, or the telescopic elements of the VHA 9103.

A further application is the "monocone method" according to CISPR 16-1-6, which is used to generate a vertical polarized field for the calibration of biconicals or hybrid antennas in the frequency range up to 300 MHz. The second N-connector can be terminated with 50 Ohms or left open, depending on the application.

A termination is recommended, if the impedance of the radiator deviates significantly from 50 Ω. This is usually the case at low frequencies (f < 30 MHz) and with short radiators (radiator length approx λ/10 or less).