The Quest to reduce QRM – Bonding

The never ending quest to reduce QRM continued after following the ARRL Grounding and Bonding book and the excellent ‘clean up your shack video’ from RSGB i have been planning to try out what is discussed.

The excellent RSGB ‘clean up your shack’ video

For my ‘shack’ i used the following components, other things like voltmeters and screwdrivers I already had.

ItemCost
GTSE Twin Pack Aluminium Foil Adhesive Duct Tape14.99
Digitus Assmann DN – 19 Earth Equipotential Bonding19.99
Items for bonding

The objective here is to ‘bond’ all the radio equipment together so it has a common earth, therefore not creating a ‘earth loop’ via the earth pin. Also it gave me the opputnity to fix things down and generally tidy the ‘shack’ radio desk up, as I would have to remove everything from the table.

The first step was to apply the duct tape. I check first that it did conduct before sticking it down ! I got the idea to try tape as I didnt want to spend on metal plates and the ARRL book some temp setups use tin-foil and baking trays – so thought this was a good compromise.

The next step was to attach the ‘earth’ bar. I put it at a ‘safe’ location to the back of the table away from where human contact should not be possible and also to give better accessability to the various earth taps on each component. I measured it up and pre-sunk the holes to screw into to make fixing a little easier

I then set about attaching all the earth, or in this case bonding, wires to the bar and positoning my KPO distribution to a place on the table. This had previously been loose and somewhat annoying and potentially dangerous. I measured up the location, pre-sunk some holes and set about attaching.

With the grounding bar connected to the distribution board I set about adding the devices. I checked for voltage first and kept the wires coiled nicely onto the now metal surface.

Comfortable that the right voltage was making it to the distribution board and the position of the feed & choke to the transceiver was good i set about adding the other components to be bonded together.

So i have completed ‘bonding’ all the HF equipment together. I will add more metal tape to the small shelf the laptop sits on and source a USB bond, which I think for the rig will complete the RF bonding of all the devices. I’ll continue to work around the ‘shack’ with more tape and bus-bars to further reduce the RF loops which go through the common ‘mains’ ground, but i’m satisfied with the measurements on the rig for now.

25/5/20 – additon

I’ve since connected the virtual earth directly to the transceiver. This is what the guidelines say to do, and I’m not about to analyse the deltas between the bus-bar and the virtual ground. When I have more experience of measuring and using the Virtual Ground I’ll see if this can be changed, for now i’m following the instructions so the wire from the ‘bus bar’ to the ‘virtual ground’ are directly connected between Tranceiver and Virtual Ground.

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