Rebuilding the Shack– from scratch
In 2014 I decided to upgrade the station, I became retired in 2013, and my use of the station was no longer weekends, and holidays. I could use it anytime I wanted, day or night. I decided I needed a better radio, and a bit more desk space. After a lot of looking, the Elecraft K3 popped up on my radar. The K3 provided me with a better radio, and a bit more desk space, exactly what I wanted. At the time of purchase for the K3, I decided it was about time to do a station rebuild, starting with the station grounding , and working my way to the Coax and antenna, and finally the control lines. This of course necessitated a complete tear down of the entire shack– right down to the operating desk. I decided that given I had a new high performance radio, I needed to be sure that the shack was as “in order” as I could make it. So the tear down began… As can be seen from the photo on the left, 10 years of neglect had left the rear wiring in a bit of a mess, and somewhat dirty. Now before you say, what a mess, look behind your operating desk… If it is clean, you are one of the few hams that actually gets behind things and keeps things clean, and you can now say “What a mess”. The entire series regarding RFI mitigation can be found here.
What a mess
After ten years of doing very little behind the desk you can see what happens… Equipment had been added, and removed over time, cables have been just draped across the rear with no real regards for any sort of order. Over all the rear of my station had become quite a mess. The thought of adding a nice new rig like the Elecraft K3 to this mess without correcting every possible issue was abhorrent to me.
No real cable organization, no wire runs, everything was just dropped in back as the station grew… I guess this can be expected, based on the number of other stations like this I have seen it is the rule not the exception. I decided to build something that worked, was maintainable and let me pull the desk out for clean up, or changes.
A ham station goes together incrementally, that is to say, first one piece, then another, then another, sometimes not in any real order, beyond what can be afforded at the time. In the sort of mess shown at the left it is very difficult to keep things like grounding and power organized. If one does not plan ahead the behind station wiring can get out of hand very quickly. Note the wall bugs all over, and the loose power strips on the floor. All of this contributed to the general mess which was the rear of my station. It also contributed to the number of birdies my station had. I had not really added any ferrite clamp on beads to anything as of yet, so the number of birdies got larger and larger. All of this had to end.
I decided that I needed to add wire runs, cable supports, and the ability to get behind the desk without having several items disconnect spontaneously. I wanted to be able to pull the desk out, and clean the floor, and maybe do a bit of re-wiring after the big install. I also wanted to layer my wiring. I spent 25 years in broadcasts, and 10 years in IT, both technologies, require the use of lots of wiring, I thought to my self, why not use the same techniques as I used for the past 35 years on my ham shack. So I decided to rewire everything using as few power cables as possible to the desk, and powering everything off the now mounted power strips. That left me with a single power cable running to the UPS, I then ran the other power strips off the first. That gave me the single AC outlet, for ground loop prevention.
Good grounding practice demands no ground loops, so I decided to power everything from a single outlet, and to give everything some isolation from the power lines as well. That dictated a UPS to isolate the radios from the power line issues, and it provided a single point for all grounds. That thought in mind, it was time to lay the grounds. I had a small ground buss already mounted, so that part was already done. I just cleaned things up on the back of the desk and floor. Next came grounding the equipment. I bought some 1 inch wide grounding strap on eBay, for a very good price a few months ago for another project. I decided to use this for grounding everything on the desk. My previous grounds were some number 8 wire. The ends used on the one inch braid were solid copper, and were found both on eBay, and a local ham fair. A fellow was selling the #4 ends for twenty five cents each, a big saving from the local radio store, which sold them for four bucks each for the smaller ones. I bought a large number of the twenty five cent copper ends… Soldering something that large, to a 1 inch wide copper braid is not easy unless you have the right tools. In this case the tool of choice was not my little soldering iron, but a BurnzOmatic torch.
That said it became paramount to have something to hold the items being soldered, as the torch gets everything connected to the flame very hot, very quickly. I build myself a little work station for making ground straps. I took inventory of my solder, and decided that the little slim solder that I used for normal soldering would not work… Off to the hardware store… I found the solder I was looking for, bug fat #14 sized solder. problem was it was Acid Core… So, looking a bit more, I found the Rosin core solder, and bought it. Back at the grounding work station I made the first ground strap. It used a huge amount of solder, and the trick for me was to not heat everything up, but just the connector, and apply the solder as quickly as possible. That way the solder stayed in the cup of the ground lug, and only a small amount wicked up the braid. If I heated things up too much , the braid would suck up massive amounts of solder, and the cup on the ground lug would never fill.
I set every piece of equipment on the desk that was going back on, and then pretended to operate it. I am glad I did, as I ended up reversing the P3 (band scope), and the K3. I pretended to operate CW, I pretended to operate SSB, I pretended to operate data… In short I pretended to be a ham for about an hour, moving various equipment around from place to place to find the best ergonomic placement. An example is the key and radio placement. I have them close to each other because I am right handed. I operate the radio and the key with the same hand. This leaves my left hand free to operate the tuner, and the P3. So after coming to a decision on equipment placement, I started to measure the lengths of grounds I needed for every item. I needed seven ground straps, one for every item in use.
The major components of the station are as follows:
LDG AT-1000PRO II
Icom 706 MK2 G
I wanted to lay the station grounds first as they would make a good base to lay the power power cables on/with, both 12 Volt, and 110 V. First thing I did was to install the cable hangers, you can see on on the left. It is the thing with the red ends on it. These hangers are available at True Value Hardware stores for about two bucks each. After working around them for a bit, I came to appreciate the use of rubber ends on them… Getting gouged by one is not fun, even with the rubber end on it.
So the ground straps were made and installed on the grounding buss. See the photo, the grey material you see is something called Pentrox. Pentrox is wonderful stuff, no matter how long it sits on something it keeps it clean, connected, and smooth to remove. So I applied Pentrox to every ground connection. If you look at the closeups you can see it sitting there on the ground buss. Now that the grounds were in place, it was time to move to power.
Addendum (05/05/14): Steve, VE3CWJ, now VE3RX has offered a comment at the end of this article, in which he asserts that Pentrox is not the best compound to use for this job, and he is exactly correct. I have removed the Pentrox from my grounds, and will be replacing it with the compound he suggested.
As can be seen from the before photos, power strips on the floor simply don’t cut it. I needed a way to get them mounted securely to the desk, and then be able to move the desk without disturbing the entire layout, or unplugging or dropping a wall wart. The normal method of mounting power strips to a wall using screws and the pre made mounting points sticks the power plugs, and wall warts sticking out the side, pointing towards the wall, and forcing a loop to each cable hanger. Also all it takes is to touch a heavy wall wart and it falls out of the power strip, so this was not an option. Off to the local hardware store again to buy more cable hangers.
The True Value hardware stores carry a small device for hanging cables, you saw one in the photo above under Grounding. It works perfectly for both cable hanging, (surprise), for mounting power strips, and for running cables. Now I had a way to mount the power strips to the desk… I set a power strip on one of these cable mounts, facing upwards, instead of towards the wall, and I then had a way of managing my cables in a much better way. I tied the power strip to only one of the wire hangers, the one closest to the main power feed. That kept it from falling off the mounts. I also was VERY CAREFUL to not have the wire tie get involved with the pop out breaker in any way. All of the wire hangers mounted, it was time to move on and start cleaning the floor and general area in back of the desk. I moved the desk out from the wall, and the first thing to do was to clean up behind the desk. This was to give myself some operating room, and a clean area to work in. Out came the vacuum. With all the dust gone, it was time to remove all the equipment and inventory it all.
The Old Equipment
That done, the equipment was removed to be cleaned and boxed, then sold. I knew all the equipment was working, so I could skip the testing part of selling a piece of equipment. Each piece of equipment was carefully cleaned, and inspected for damage. Any damage was noted for later, when the equipment was photographed for sale. I wanted to be sure that any issues of any kind were shown in the photos. I then photographed each item, wound all cables neatly, and boxed for shipment each item. That done I was left with an empty desk, and an bare floor behind the desk. This created my work space. All of this also took about half a day. I decided that doing this in one day was not reasonable, and would force a compromise or two. So I removed all time limits, and told myself, and my wife that it might be a few days with the desk out from the wall and equipment everywhere. Bless her heart she said no problem, I should take my time and do it right. She knows me too well!
Installing the wiring
First as I said it was time to run grounds to all equipment. Remember the equipment was still on the desk for ergonomic testing. I measured the length from a mounting hole in the ground bus to each piece of equipment, then went outside to the ground work station and built the ground strap. The ground strap was installed, using the Pentrox discussed above. I got burned once by not paying attention to which way the ground lug was facing. In the one to the left, you can see that both lugs are facing the same way. This is not always the case, depending on the route. So I hand routed each one, then remembered the correct orientations needed as I built each ground strap. This resulted in several finished grounding straps. I unpacked the all of the equipment, and then began setting it on the desk in the layout I had found worked best earlier. I then connected all grounds. This includes the computer grounds as well… To ground a computer I found a screw that I could back out add the ground lug, (with Pentrox), then re-tighten. I am pretty sure that this step removed most of the RF birdies I had. Yes I did spot the lock washer, and put it back in the amp ground.
Next came AC power, I mounted three power strips on the desk, (note that the breaker buttons are unobstructed), and then labeled each one with a single word, “Clean”. That indicated that the power came from a UPS, and not just a wall outlet. I labeled the single one I had that was not from the UPS as “Dirty”. I use single power strip to power things like clocks, and items not connected to the ground bus. The UPS gives me about three minutes of power once pulled from the wall. That is enough time to kill everything. The computers kill themselves, in under one minute, so all I really need to worry about is the radios. I want to add a power gate someday, and a 12 volt battery in addition to the UPS, but that will be easy when the time comes. Please note that the power cables you see to the left are not in their final layout. As can be seen below the final power and ground, (with some RF cables in place), came out rather nice.
A better, cleaner place
With power and ground mostly layered in, it was time for 12 volt power. This was easily threaded in and around the AC as can be seen below. The more I used the cable hangers, the more I liked them. So… Off to the hardware store again… I bought a few more for the upper portion of the desk, and installed them. That done, I started running low voltage power. It is at this point I began installing mix31 ferrite clamp on beads. Lots of them, the final count was something like 50 ferrites ended up being used. Why so many? I wanted to never again deal with any sort of common mode– in my life! I had the ferrites, so I decided to use them. I keep a kit for use by others when I look for RFI for our club members. This also gave me an excuse to order more… With 110 volt and 12 volt power, and grounds in place, it was time to install the control cables, and add ferrites to them as well. All the control cables went in next, they were threaded in and around the 110 volt and 12 volt wiring. Ferrite beads were added as well. With the current wiring, I can slide the desk out, and add, or remove things, and not have a wall wart fall out of a connector, nor do I run the risk of tripping on a cable on the floor.
The Final layout
As you can see the 12 volt layout was pretty simple, 12 volts in, and 12 volts out. I selected a Rigrunner because of the RFI filtering, and the ease of install, and the use of power poles. I did bolt on a wood backing to support any equipment I needed to mount. I picked up the Rigrunner 4008. and a Powerwerx SS-DV30 power supply from someplace on the web, and began installing.
Later on I will be adding a power gate in the empty area below the Rigrunner, and a 12 volt battery on the floor. The power distribution panel sits on the vertical part of the desk, and feeds everything on the desk that takes 12 volts for operation. I picked this supply because several people I know say they have one, and say it is rugged, and has no RFI associated with it. Not shown are the Ferrite clamp on beads on each cable, both into and out of the Rigrunner. I probably don’t need the ferrites on the rigrunner, as it contains RFI shielding internally as well.
All in all this was not a small project, it took on the order of two full days at eight hours a day to both clean up, and start from scratch on the operating position. It also takes a wife that will put up with a large mess for a few days in the living room. This is a project I should have done years ago.
Now that the shack is clean, wired correctly, grounded correctly, and in general working better, I will not allow it to return to the previous condition. Overall changes have been very easy to implement, and easy to document. The addition of the mix31 ferrite clamp on beads have made a very noticeable difference in the number and level of birdies around the station. I am very happy with the results of the decision to redo the shack, and do not regret it at all. In fact, my next project is to redo the wiring for the radio in the little camp trailer. I now have a portion of this site dedicated to providing RFI signatures as visualized by SDR. It is located here…