Upgrade: Copperhead (RF Noise Shielding vs Wireless Mic)

Welcome to 2017!

In my last post of 2016, I mentioned how running the wireless mic in my helmet made a lot of radio/ RF noise in my hearing assist system. I decided to tackle it in a couple of ways. I did this work before the end of 2016 but only now have enough time to put words to the blog and write about it.

The first thing I tried was to add EM shielding to the mic lead wires from the mics under each of my bucket ear pieces. I did this using tinned copper metal braided sleeving from Amazon. I cut the length necessary for each lead wire and carefully threaded the wire through the sleeving as I expanded and contracted it to increase the sleeve's diameter. This was really tricky and a giant pain, but I ended up getting it done as you can see below. After installing the sleeves I used already-placed shrink wrap to seal up the frayed ends.

After testing, though, this proved to not be too effective. In hindsight, if I had to do it over again, I probably would have used shielded cable to start, but I'm not sure it would have been more effective than the aftermarket shielding I used.

Knowing the shielding may not do the tick, I resorted to my second and more extreme option, one used by musicians using wireless pickups: copper tape.

Copper tape is very conductive and a great way to create EM shielding to prevent noise on lines, create small Farady cages, etc. Since most of my cabling will be tucked behind the wiring bracket I created for my fan system and mounting the hearing assist system, it was the ideal place to install the copper tape, especially since the wireless mic would be mounted on the other side of the tape, with the tape protecting the cable side from noise.

After removing some H&L tape and other hardware, I tediously covered one side of the bracket with copper tape. I decided to do this on the side facing the inside of the bucket as to not require removing all of the previously installed hardware. If I had to redo the entire bracket, I'd probably put it on the other side, but it is what it is, and not visible when I'm wearing the bucket. Plus I don't have to worry about the (remote) possibility of wires shorting out on the copper tape.

After the tape was on, I re-added the H&L tape for the hearing assist and wireless mic, reinstalled the bracket into the bucket and tested.

And wouldn't you know it, throwing a ton of copper tape at the issue worked. There was still a little noise with the bucket off, but with the bucket on and my head in the bucket blocking the rest of the RF noise, it works much, much better than before.

You can also see above that I moved the battery for the bucket systems into the forehead, for two reasons:

1. It makes putting the bucket on easier since the opening is now slightly less narrow without the battery in the back of the helmet (especially since I'll need to worry about the wireless mic now when donning the helmet).
2. In its new home, it keeps my forehead from running into the blower fans also mounted in the forehead (which ended up being an issue during a holiday troop).

Now that EM noise from the fans and RF noise from the wireless mic have both been solved, I'm effectively done messing the the bucket for now. Next, I plan to try out a TKTalkie system that I'll mount int he chest plate with the wireless mic receiver and Pyle Pro personal PA.

And eventually obtaining the hand plates and doing the other stuff for Elite Infantry :P

One more note: you may have noticed that I changed the name for my blog. This is because I changed my 501st nickname across the board to better reflect my TK persona and my personal TK logo. I'm leaving the URL as-is because it would break every older link to the blog if I changed it without paying for a URL redirect service. So for the time being, you can still find the blog at obsidiustk.blogspot.com

Until next time...