[Wyndell Ferguson]

Ive been trying to track down some RFI in and around my shack… Something I should have known but didnt think about: Wireless keyboards and wireless mouse (mice?).  Im growing concerned my wireless routers may be an issue too

 

73 de Wyndell K5WJF

[Steven Smith]

Wyndell

The first step is to determine if any of these noise sources are detracting from your full enjoyment of your station.

If Not then I would press on with other things first, such as ensuring that my station is Grounded and Bonded to Industry standards.
And that means getting the Grounding and Bonding for Amateur Radio Stations book written by Ward Silver, and reading it and then following his guidance step by step, zero short cuts.

I will get back to RFI solutions in a moment, but lets discuss this Lightning protection a bit further….

The most grievance mistake many amateurs make is to just use a ground rod for their station and not bonding their station ground to their AC Utility Service Ground (never disconnect your AC service ground just add another ground clamp for the new connection).

Many amateur radio ops are really surprised to hear that I never disconnect anything from my shack, when not using it.
Far too many amateurs still think that they need to disconnect the coax from their radio(s) when lightning is in the area, fact is lightning more often does not enter the shack from the antenna (unless your antenna system has zero lightning protection and in that case you need to attend to that now)

A question for anyone that believes they must disconnect their equipment to be safe from lightning damage……..

How often do you believe public service station (like DPS and Fire) disconnect their equipment during lightning storms?
Same question for TV and Radio Stations, the answer of course is Never and they suffer zero damage.

They suffer zero damage because the equipment is Grounded and Bonded throughout the site, to industry standards.

The same is true for most large amateur radio stations, where a simply act of disconnecting everything would take hours.

A glance at K3LR’s station on the QRZ.com site will reinforce this will take at least an hour or more to disconnect just the coax and like I stated before most of the damage, at least in a station that has the feedlines protected with lightning arrestors will come from the AC mains.
Tim has over a dozen HF rigs, each one of his rigs cost well over $10 thousand dollars, yes you read that correctly.

His station is NEVER disconnected for lightning safety.

If you are simply disconnecting coax and turning the radio(s) off, you are not protected and I hope you have good insurance for anything that is electrical inside the house and the ham shack.

Most lightning damage is from the difference in voltage potential between the utility Ground and the shack ground,
if these two ground rods are not Bonded together then the soil between the two acts as a large resistor, providing a substantial voltage drop between the two grounds, that difference in potential is going somewhere, often into the electrical appliances in your home (Refrigerator, TV, sewing machine) or something in you ham shack.

Grounding AND Bonding is the most important thing we as amateur radio ops should do and do it correctly, zero short cuts.

Now back to your original subject…..

In shack RFI is more often caused at higher levels by wall warts (small ac to dc adapters)
Wall warts are simple Switching DC power supplies, almost all inexpensive DC Switching power supplies will cause RFI.

So the first step in having and RFI clean shack is zero DC switching power supplies.

I have two such designed supplies in my shack and two wall warts that I have thoroughly tested and they do not emit RFI.

I also use RFI elimination tools…….

Toroid’s, made with the right materials not cheap toroid Imation material

I use Amidon Material such as the toroid’s found here………..
https://www.kf7p.com/KF7P/RF_chokes.html

I also use a product from DX Engineers for all of my Internet and computer Lan Cables….

https://www.dxengineering.com/parts/dxe-iso-plus-10

The -10 is for a Ten count package, your needs might suffice with the simple two package
These things work and work well, I have 12 of then in use in my station and in the house.

Speaking of the House,
There are three homes here on the property where we live
One is the wife and I’s home and the other two are her mom and my mom’s

Nothing is in any of these buildings that causes me RFI in my radio.

I keep spectrum print outs of how clean the bands are here
and we do not add anything here on our property that causes noise in my HF radios.
Most amateurs can not control what their nearby neighbors have as far as I can.

RFI can also come from other antennas when they are not in use and even the antenna we are using if we do not use good quality 1:1 baluns to isolate the common mode noise that exist on the feedlines.
Again use good engineering standards for connections, every where in you Antenna and Grounds systems.

The most important thing is get on the air and have fun
Once you have ensured everything is installed right for safety.

Cheers!

Steve KG5VK

 

 

[Wyndell Ferguson]

Thank you sir! Very informative information!

73, K3WJF – Wyndell

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