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Water and Electronics, a match made in hell ...

Discussion in 'Amateur Radio News' started by VK6FLAB, Aug 4, 2018.

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  1. VK6FLAB

    VK6FLAB Ham Member QRZ Page

    foundations-of-amateur-radio_300.jpg
    Foundations of Amateur Radio

    Water and Electronics, a match made in hell ...

    It's been raining around here for a while now. Not in the order of 40 days and 40 nights, but significant. Mind you, I have lived in a place where it rained every day for 57 days, but I digress.

    Water, plenty of it and often in all the wrong places.

    Being a radio amateur you come across water in many aspects of the hobby, sometimes it comes in handy, like lubricating your throat while you're calling CQ, or as a ground plane for an antenna, other times, not so much, like when it enters the shack and causes the black smoke to escape from your pride and joy.

    As I said, I'm no stranger to rain and in my travels I've encountered plenty of it. I managed to travel around Australia for a couple of years and I took with me a two-way satellite dish with sensitive electronics attached. Living in Australia I planned for dry. This place is dry. Often very much so, but as it turns out, dry doesn't mean without humidity, storms, rain or in one case hail.

    These experiences told me a little about protecting electronics from the weather.

    I should add a disclaimer here, I'm not a certified weatherman, nor am I certified in waterproofing, water ingress, or any other guarantee. So, if you do as I say and it breaks, you get to keep both halves. That said, I have some thoughts on the matter and I wouldn't be me if I didn't share them.

    Water is generally everywhere. It gets into everything and it's one of those silent killers. Electronics and water rarely mix, unless you submerge the electronics in mineral spirits, or if you seal your electronics in circuit board lacquer. Even then, there are few guarantees.

    The best you can hope for, in my experience, is to plan for failure, hope for success.

    Finding where water gets in is often the hardest part of keeping it out. Sealing off your electronics from the world in a waterproof anything will trap heat, which in turn will cause condensation, which will ultimately cause rust and destruction of your priceless electronics.

    Giving your stuff time to acclimatise is a very good idea. For example, if you have a radio stored in your garage and you bring it indoors, leave it there for several hours, if not overnight. Unless you live in Alaska with an in-floor heater to prevent your engine block from freezing, your garage is cold, your home is warm, the combination causes condensation. Alternatively, if your garage is hot, and your home air-conditioned, the reverse is true and condensation will still happen.

    Water has a habit of finding its way into anything, encouraged by gravity. That means that a length of coax, run into your wall will attract a stream of water along the coax, straight into the connector and into your wall, or between the core and the braid, or into your radio, or some other undesirable place. If you create a low point before the connector, like a drip-loop, a place where water would have to go up before it can do damage, you'll likely solve the issue, but don't discard the effects of wind which can cause water to go uphill.

    Connectors are magnets for water. Most connections in use in amateur radio have little or no waterproof rating. There are special waterproof connectors about and you may consider using those, but alternatives like self-amalgamating or rubber tape, which you wind tightly around a connection and in doing so, stretches and glues itself together to keep the water out. These tapes are generally not stable in the ultraviolet of the sun, so you may have to wrap that sealed connector in another layer of tape, plumbing or electrical tape is one solution.

    Based on the experience from national coax installations, the way to do this is with three windings of rubber tape, followed by two of plumbing tape. Think of up as towards the weather and down as away from the weather and make the windings like this:

    Wind the rubber tape three times around the connector, up, then down, then up again.

    Seal this from the sun with two windings of plumbing tape, down and then back up towards the weather.

    For endurance, add a cable-tie to keep the tape in place when the glue eventually fails. This will ensure that water always runs away from the connector.

    The way to remember this, for a positive result, there are three ups and two downs.

    If you ever get your coax wet, that is, the end, be prepared to cut off a length to protect your gear. Coax rot is real and is essentially the rusting of the braid, the shield or the core and it spells bad news for your gear.

    Operating portable is a whole other subject in relation to weather, but the same principles apply. Keep the temperature stable, keep the water out, protect from rain ingress along the coax and you'll likely be able to have a good time and come home without any damage to your gear.

    There is a persistent idea that rice can help you dry electronics. While it does have some effect, it's slow and by the time it's removed the water, the damage will already have been done. Air drying is much more effective. Use a fan, keep it running and you'll have a better chance of rescuing a drowned circuit.

    As for electricity and water, they don't mix, they can kill and you should know better.

    I'm Onno VK6FLAB

    To listen to the podcast, visit the website: http://podcasts.itmaze.com.au/foundations/ and scroll to the bottom for the latest episode. You can also use your podcast tool of choice and search for my callsign, VK6FLAB, or you can read the book, look for my callsign on your local Amazon store, or visit my author page: http://amazon.com/author/owh

    If you'd like to participate in discussion about the podcast or about amateur radio, you can visit the Facebook group: https://www.facebook.com/groups/foundations.itmaze

    Feel free to get in touch directly via email: onno@itmaze.com.au, or follow on twitter: @VK6FLAB (http://twitter.com/vk6flab/)

    If you'd like to join the weekly net for new and returning amateurs, check out the details at http://ftroop.vk6.net, the net runs every week on Saturday, from 00:00 to 01:00 UTC on Echolink, IRLP, AllStar Link and 2m FM via various repeaters.
     
    W4MMR, EA3GNH, W3MT and 3 others like this.
  2. NU4R

    NU4R Ham Member QRZ Page

    If "air" will dry my seeming perpetually soaking wet golden retriever, it'll surely dry soaked electronics! Though, I've NEVER tried drying her in rice.

    All kidding aside...good stuff Onno! 73!
     
  3. AB2YC

    AB2YC Premium Subscriber QRZ Page

    I have washed out with water many pieces of electronics gear over the years.
    Wash it out then put it with a fan blowing on it (or over furnace register etc.).

    Water can be your best friend when cleaning electronics out, it's
    far gentler than many other solvents and pure water is residue free.
     
    KN4OND, AJ4LN and KI7HSB like this.
  4. KA9JLM

    KA9JLM Ham Member QRZ Page

    Water is life.

    Just need the correct type of water.
     
  5. K7YVO

    K7YVO Premium Subscriber QRZ Page

    FYI...pure water is a perfect insulator and will not boil
     
  6. K9CTB

    K9CTB Ham Member QRZ Page

    When I was in naval electronics school <garble> years ago, I had this great (to me at least) civilian instructor who beat it into me that "dirt is death" in electronic equipment. I later learned that, so is water .... and the combination of the two is an even quicker death. I never forgot the lesson. Now my ham gear is pristine on the inside, compared to my shack floor which needs sweeping even as I write this!! :)
     
  7. K9CTB

    K9CTB Ham Member QRZ Page

    Once that pure water touches a wire or circuit board, it becomes an instant conductor. Try it yourself. On the "will not boil" part, um, just plain no. Ask any Operating Engineer for a demonstration.
     
    KE7NHK and 10XSHOOTER like this.
  8. KF5UMC

    KF5UMC Ham Member QRZ Page

    DI water is used to clean "wafers' that contain many IC's prior to being cut into small pieces and placed into a chip. Water is also a wonderful thing in the right place. I also travel around the country and have found after a good rain the counterpoise or ground plane improves and my signal and reception is better with the vertical antenna. I have found through trial and error, that hanging up a dipole antenna between oak trees, with the feedline too close to the trunk of a tree will adversely affect the SWR.
     
  9. W1UO

    W1UO Ham Member QRZ Page

    Deionized pure water is a poor electrical conductor, having a resistivity of 18.2 million ohm-cm (18.2 megohm).

    When I worked at VOA, all the big transmitter tubes were water cooled, with tens of thousands of volts on the plates. No arcs, no sparks.
     
  10. G0WXU

    G0WXU Ham Member QRZ Page

    Regarding water cooling tubes (Valves). That was a point of great interest to me as a young Royal Signal operator who had the chance to look into an "E10 Transmitter" many years ago. There was this bloody great glass tube, glowing nicely with water cooling pipes connected up and warning notices for ensuring that the water supply was on at the correct pressure before transmitting. No operator safety notices were to be seen. It was presumed that you would have the sense to keep well away from Anode connection when power was running. The feeling of power, knowing that just one touch of the key would send a signal out across the world. Doing the Marconi thing. while on training at Catterick, I was located very close to one end of an E10 transmitter antenna with my 1Watt output transceiver and vertical whip antenna. I was part of a small CW net of stations around the Catterick Garrison area. We had not been on the air for very long before getting a visit from our instructors telling us to pack-up ready to move. Apparently, my CW signal was being picked up along with the E10 teleprinter signal and causing QRM on the received printer signal in Hong Kong. Work that out for QRP BCI.
     
    EA3GNH, KN4OND and KU4GW like this.

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