Ofcom’s spectrum assurance team recently solved a sky-high interference case that took more than a little detective work to crack.
The team were contacted by National Air Traffic Services to let them know that aircrafts flying in and out of Glasgow airport were being affected by interference when they were between 6,000 and 10,000 feet in the air.
The interference was affecting voice communications between the controllers on the ground and the aircraft. Whenever the aircraft were in the vicinity of the interference the crew would not hear any air traffic control messages as the signal was swamped by the noise of the interference.
But what was causing the problem – and crucially, where was it? The next step was for the team to locate and identify the source of the interference.
However, due to the height of the aircraft (not to mention the speed of their flight!), the team described how identifying a potential cause would be like looking for a needle in a haystack.
Our spectrum engineering officers spoke to the National Air Traffic Services (NATS) in order to narrow down the search area.
They were able to create an ‘area of probability’ on a map, in which they could focus the search for the source. This was done by using flight-tracking software, which allowed them to make a note of where the aircraft were when they reported the issue – and this in turn helped to identify a corresponding location on the ground.
Following this discovery, the search turned into a ground-level investigation centred on a small town.
This monitoring involved using vehicle mounted receivers and driving the suspected area until the interference was heard. Once the team have located a location where the signal is strongest they then use hand held equipment to cover the remainder of the search area on foot. The team visited a number of properties that were adjacent to the property where they eventually located the source. After a search phase, the source of the interference was found to be a home. Specifically, the cause was four ‘vintage’ lightbulbs that the homeowner had recently bought online.
What’s that noise?
Due to the construction of the bulbs, they were found to be radiating a ‘noise’ when they were switched on that affected a wide range of spectrum, rather than just one frequency. The house was directly underneath the flightpath of the aircraft and therefore every time an aircraft passed and the bulbs were in use, the crew suffered the interference.
Unfortunately for the owner – but fortunately for the crew and passengers of flights in and out of Glasgow airport – the bulbs were removed from the sockets and checks with NATS and aircraft operators confirm that the area is now free of interference.
Now our spectrum enforcement team will follow up the case with the lightbulb suppliers, to make sure the bulbs aren’t sold to any more unwitting customers.
What is spectrum?
You can’t see or feel radio spectrum. But any device that communicates wirelessly needs spectrum – such as televisions, car key fobs, baby monitors, wireless microphones and satellites. Mobile phones use spectrum to connect to a local mast so people can make calls and access the internet.
Why does Ofcom manage spectrum use?
Only a limited amount of spectrum is available, so it needs to be managed carefully. Certain bands of spectrum are also used for different purposes. For example, mobile companies use different parts of the spectrum to TV companies. So, it needs to be managed to prevent services interfering and causing disruption to people and businesses.
Source:RSGB
Equipment
Lido Radio Mounts
Lido mounts are a great way to mount your radio in your mobile. Read more
Barrett 4075 High Power HF Transmitter
The Barrett 4075 high power HF Transmitter is a compact rack mounted communications solution developed for base station applications in large HF netwo... Read more
THE NEW HEIL HAM RADIO!
“First, we would like to thank you for your continued support of our company and products. As Heil Sound Communications continues to grow we wan... Read more
Introducing SDRconnect – SDRplay Hamvention 2022 demo
This video shows the demo we are showing this weekend (May 20-22) at Hamvention in Dayton, Ohio. This demonstrates the core underlying technology behi... Read more
ACOM 2020S | Solid-State 1.8-54 MHz Linear Amplifier
ACOM 2020S | Solid-State 1.8-54 MHz Linear Amplifier Easy to operateThe overall operation of ACOM 2020S is extremely simplified: the touch screen menu... Read more
Review
Venus Technologies SW-3B QRP CW Transceiver Review
Looking at the Venus Technologies SW-3B QRP CW Transceiver for 20/30/40 meters. Dimensions: 104*71*25mm (excluding the protruding part such as kn... Read more
Stellar x2 vs RE20 vs RE27ND Microphone Review
“We compare the Stellar x2 vs RE27 vs RE20 from Electrovoice. I was amazed with this Microphone and as soon as the new Mixer arrives, we’l... Read more
Stay away from cheap coax
A viewer asks about some inexpensive coax they found online. Is it any good? We talk about that and why you may want to stay away from cable that has... Read more
XIEGU G106 – First Look at this New HF Transceiver
XIEGU G106 Xiegu keep themselves pretty busy developing cost effective QRP transceivers. This new model is a replacement for the G1M. Peter G3OJV gets... Read more
Battery Powered Automatic Antenna Tuner, 100 Watt Max, Portable Ham Radio Tuner Review/Demo
“Here is a small $100 portable battery powered ham radio antenna tuner, which deserves a review. I have it connected to my Icom IC-705 but you c... Read more
VHF
Icom IC-T10 Rugged Dual Band HT @ HamVention
Icom IC-T10 Rugged Dual Band HT This New VHF/UHF HT from Icom features a Very Rugged Design, 1500 mW of loud, clear speaker audio, 2400 mAH battery, I... Read more
Icom VE-SP1 LTE/PoC Radio Desktop Conference Microphone
A short video about the Icom VE-SP1 desktop conference speaker microphone which enables a simultaneous voice conference in multiple locations by combi... Read more
Iridium Command Center Explanation – ICOM
Icom’s satellite radios utilize Iridium’s constellation of Low Earth Orbit satellites. With this network, you can set up to 2,250,000 square kilometer... Read more
ICOM IC-T10 – Released April 2022. What are its Main Features
A first look at the new Icom IC-T10. Dual Band Transceiver ICOM IC-10 PDF File https://icomuk.co.uk/files/icom/PDF/newsFile/IC-T10_A4.pdf Read more
Icom ID-52 Quick Look And Highlights
My newest radio is the new ID-52 by Icom. I have had this a bit over a month and finally starting making videos on it, just to show you why I think th... Read more
Antenna
Inflatable Satellite Antenna
Inflatable Satellite Antenna GATR 2.4m Inflatable Ku & C Band Satellite Antenna VSAT Satcom Deployable Up for auction is an GATR 2.4m inflatable a... Read more
You are using the WRONG toroid for an EFHW Antenna, Maybe!
Did you know, not all Toroids are created the same? They may look the same, but there is one big difference! UPDATE: I’m sorry, in the video I w... Read more
7 BAND HF COBWEB ANTENNA – 1 KW
COBWEB ANTENNA Multiband cobweb antenna works on 7 HF bands and up to 1000w. Bands are 14,18,21,24,28,50,70 MHz Built and modified by me for my friend... Read more
DIAMOND HF MOBILE “CL” SERIES ANTENNAS
The Diamond HF Mobile “CL” Series Antennas are a bit special. Centre Loafing is claomed to be superior to base loafing. Peter G3OJV, tests... Read more
Diamond D3000N Super Discone Ultra-Wideband Antenna
“In this video we cover the assembly, installation and testing of the 3000N Discone for use on an SDR and home scanner.” Ultra-wideband de... Read more