System RFI test

Team members preparing for system RFI testing

Campaign review

Reviewing all the elements of a measurement campaign is essential. This happens on every occasion. From left: Howard Reader, Joely Andriambeloson, Kurt Coetzer and Gideon Wiid. (SANSA PV & Ionosonde Measurements April 2023)

Dielectric measurements

Material dielectric measurements are often requested as clients wish to understand the electromagnetic consequences. Prof. Johannes Cloete and Dr Gronum Smith developed the free-space system depicted. Calibration with time-domain techniques is key. (University of Stellenbosch, EEEng facility)

Typical system analysis

Detailed emission profile characterisation. Strong pulsed behaviour seen here.

Customised LPDA measurement

MESA, in conjunction with different researchers, has optimised various LPDA antennas. The picture shows the Keith Log Periodic Dipole Array antenna detecting background emissions along an SKA spiral arm position. (RFI-Site Audit February 2023)

Background RFI testing

Doing a pre-evaluation to confirm expected RFI levels (RFI-Site Audit February 2023)

Full RFI testing team

From left: Howard Reader, Joely Andriambeloson, Kurt Coetzer, Fred Pretorius, Gerhard Botha, Graeme Young, Johan Havenga, Siyabulela Tshongweni, Antheun Botha, Braam Otto. (October 2022)

Telescope shielding tests

Howard and Kurt taking measurements with a horn antenna. (MeerKAT Retrofit campaign, Oct 2022)

EMI from cable in soil measurement

Joely and Casey evaluating cable EMI under different soil conditions on a campaign in July 2022

Tracking cable interference currents

Common-mode currents on cables going to PV arrays cause significant interference and need to be understood. Casey getting his hands dirty for the greater cause.

Novel MESA Shieldex EMC cabinet

Modern high speed spectrum analysers exhibit self-generated EMI. The ultra-lightweight cabinet shown was developed in a collaboration between MESA and Shieldex. The EMC cabinet makes it possible to remove this interference for very sensitive measurements.

Original EMC cabinet

MESA's original, bulky brass cabinet for self-generated EMI mitigation. This is necessary for highly sensitive measurements. Cabinet now replaced with light-weight prototype.

Lightning interference check

Monitoring telescope grounding connections for possible signal leakage.

Generator interference testing

Testing generator common-mode currents at South African National Space Agency (SANSA)

Low frequency evaluation

Using the Rohde & Schwarz HFH2-Z2 magnetic loop antenna for VLF

Building emission testing

SANSA generator radiated measurements.

Pre-Compliance Testing

Jointly-developed reverberation chamber between MESA and SARAO at the Houwteq testing facility near Grabouw.

Typical pre-compliance investigation

Pre-compliance testing in the reverberation chamber with an emphasis on diagnostics.