My home location is nestled in a townhouse complex in Franklin, in Canberra’s northeast.
My HF antenna is a random wire from my entrance up to the balcony and back down. Best described as an end fed inverted v. It will tune on all usable vk hf bands. Home rig is my only rig. 817nd, z817 auto tuner. Shown here:
As with all modern urban environments, there is RF Noise everywhere. While I accept I can not control what RF noise my neighbours make, I wanted to take control of my noise which ranged from S9+ to S7 on a quiet day at home.
The following are the steps I took that now has my noise floor ranging from zero ( I keep checking that the antenna is connected) to about s2-3 which is my common QTH band.
Step one: If it isn't hidden in a wall it was checked with an AM radio - I wandered around the house poking behind TVs, bedside tables, shack / study, garage and laundry.
Result: 2 largest noise emitters so far - old xp shack laptop charger (6s points on its own) and then the cumulative powerboard of shite that lives behind the TV made up of about 6 wall warts that power TV, DVD, surround sound etc.
Next, I turned everything off at the meter box and worked circuit by circuit running backwards and forwards to my radio to see the noise floor change.
Because I have the 817 ready to rig for SOTA or /p work I ran it off the battery and was blown away when I connected it to the wall charger I use to top off the internal battery… s7 alone!
Armed with these facts I set about OPERATION RF QUIETING.
AKA: ferrite the crap out of everything. I spent about 60 AUD on 3 large high-grade snap-on ferrites from the US, plus about another 20 on smaller ones from Jaycar.
Deployed as follows:
1 large around the washing machine’s power cable, when in use it generated a rhythmic hum across all bands - not any longer
1 large on the power cable for the TV power board
1 large on the Yaesu power cable
2 x medium on antenna feed coax (-2S points)
1 x medium on the XP Laptop charging cable - about 7 turns got it down to less than 1 s point from 6
The hunt is still not over, with any noise detected on the radio eliciting a ‘WHAT DID YOU JUST TURN ON” shout from the shack to my accommodating XYM, I am pleased to report the answer is always “nothing” meaning it was external to the house.
https://au.mouser.com/ProductDetail/Fair-Rite/0431177081?qs=KmHvPbTOE4RJzgtUylmsjQ%3d%3d - ignore the sales picture these are large