TV OR NOT TV? – a Case Study By Ian Jackson VK3BUF Editor’s Note: Whilst this article relates to a television reception problem, the underlying issues and processes employed by Ian apply to amateur radio. The subject could just as easily have been an amateur radio receiver as opposed to a television. This is also […]
Category: Case Studies
Solar Panels and Micro-Inverter
“I negotiated with my installer to put ferrites on the leads from the Enphase micro-inverters, to agree to work with me (at my expense) to mitigate any RFI, and to assure me that I could switch off the system while operating the radio if all else failed. The system is completely quiet, directly under my […]
A noisy Brivis Air Conditioner
QRM GURU – A CASE STUDY Air Conditioner Plant Makes S9 Noise at Home Klaus Illhart VK3IU had a significant noise problem that made HF operations difficult. Klaus has prepared a detailed description of the process of tracing and resolving the source of the interference. Here we have an abbreviated version to give readers a […]
HDMI Interference
HDMI – HIGHLY DEPENDABLE MOBILE INTERFERENCE QRM from your PC? There are probably millions of screens around the world which use HDMI video connections. HDMI is supposed to stand for ‘High Definition Multimedia Interface’ but in Amateur Radio circles it can sometimes cause annoying interference problems. The HDMI standard is quite complex, with several […]
Mitigating Amateur Radio Interference to VDSL2
NBN Co. have recently published a very helpful article on Amateur Radio interference and the NBN. The PDF can be downloaded from the NBN website; click on the image below. You’ll also find plans for a simple 40m notch filter here, thanks to Andrew VK3FS.
Low power wireless charging: friend or foe?
By Ian Jackson, VK3BUF On a recent visit to Aldi, I couldn’t help but notice some new products stacked up in the centre aisle. There was a handheld LED lantern and a wall-mounted emergency lamp. The larger lamp had warm-white and colour-changing modes. The smaller unit plugged into an electrical outlet and activated automatically with […]
The saga of the network switch and 20m QRM
These days, the internet is connected to just about everything electronic in the modern house, from TVs to refrigerators. My family and I are serious internet users, so when the new QTH was being built, I had the electricians run Cat6 cable to 14 outlets throughout the house. I installed a 24 port network IP […]
How’s your noise floor?
By Bob VK3XP I have lived in my present location for over 40 years, and in the early days the noise floor was just detectable. These days it ranges from S3 to S8 to 9. So, how does one go about finding where the noise is coming from? Over the years I have built a […]
QRM to Telstra NBN FTTN modem
This great case study from a VK amateur…. I have a Telstra NBN modem, used for a FTTN service. It is installed on a shelf in the garage My 40m dipole runs across the garage – the end is about 7m away from the modem. Whenever I transmitted, RF would cause the modem to lose […]
Audit your power packs / wall warts
Check your power supplies With the New Year comes New Year Resolutions. The little 5V plug pack that came with the laser show Christmas Present was stamped with a working range of 100 – 240VAC, 50/60 Hz. It will work well in the USA on 110V and even in China where the mean voltage is […]