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 […]
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 […]
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 […]
Ian VK3BUF has put together an informative short video based on his popular article The Truth about Ferrites. If you’d like to look at our Ferrite kits, follow this link.
Radio Frequency Interference (RFI), QRM or noise, has become one of the single largest impediments to HF operation in any urban environment. This post covers the basic philosophies to help you identify and get on track to resolve your noise issues. RFI in some urban environments may appear unsolvable, but by working through the methods […]
Here is a simple list of tools you’ll need to start searching for noise: a small DF loop, like this one for VHF and UHF, a Yagi or other directional antenna. Say something around 8db gain a simple wide band AM receiver or a 2/70 handheld for higher frequency work – two suitable options are […]
This is a simple example of how you might conduct the first step in identifying the noise/s. John has moved to a new QTH has has some noise issues. John is using the log sheet and profiling sheet found under Templates. He is keeping a detailed journal. John notes that every time he turns on […]
This post provides links to some useful sites and resources to help you identify your noise. Please send us any additional resources or links you know about. Two common and sometimes misunderstood terms (or Q-codes) are QRM and QRN. The images below provide a high level explanation of the difference between QRM and QRN. This […]