EMC issues in cockpit screens

The Federal Aviation Authority FAA has told airlines to replace or modify the cockpit display units. These were apparently designed without consideration for Electromagnetic Compatibility (EMC)

US air safety regulator said that tests had indicated that mobile phone and computer signals could cause the screens to go blank. The affected planes are typically fitted with several screens, each of which costs thousands of pounds.

Honeywell - the displays' manufacturer - has stressed that the problem has not been experienced in-flight.

Full story -  http://www.bbc.co.uk/news/technology-29445385

Wi-Fi interference with Honeywell avionics prompts Boeing action - http://www.flightglobal.com/news/articles/wi-fi-interference-with-honeywell-avionics-prompts-boeing-354179/

Fishy Radio Interference

Christchurch (New Zealand) radio inspectors were involved with a commercial interference case affecting a major microwave link in the upper South Island.

The microwave operator was able to identify that the link was only being affected when the same fishing vessel crossed its path in the Cook Strait. This led the inspectors to a number of conclusions however the only possible way to determine the interference was to position themselves on a hilltop overlooking the Strait. Using a microwave dish and sufficient gain they were able to see the interfering signals radiating from the fishing boat. By utilising the AIS vessel tracking website their position was verified.

It was obvious that the fishing boat was the cause of the interference, however what was not known was why it was emitting these transient signals. The radio frequency signature of the noise looked to be very similar to the S Band radar aboard the vessel.

The fishing company was called and the S Band radar was turned off. Immediately the noise ceased and it was obvious that this was the cause of the interference. A subsequent letter was sent to the fishing company and the S Band radar’s magnetron was replaced.

Yagi Radio Antenna Designer Website

Derek Hilleard G4CQM, has launched a new website which details only his very best VHF/UHF AOWA & FLOWA yagi designs produced in the last two years.

The difference is a full and forensic analysis of each design including Q-factor which has been ignored for too many years!

Myths surrounding reflectorless yagis have also been explored.

Visit - http://www.antennadesigner.co.uk/