remote operating in the Great White North - keeping the radio warm

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As most of you know, my HF station is 100% remote up here in the Great White North.  The secure radio room can easily see some pretty cold temperatures of -15C or greater.

A while back, I talked to Steve Hicks N5AC about cold weather operating and he brought up to speed on "cold weather hardening" for electronics and things like the FPGA, etc.  As Flex radios are not cold weather hardened, that can be a concern.  Steve's comments to me was to just leave it on as the FPGA generates about 5-7 watts of heat on its own.  That is what I did  all winter and it worked just fine.  I had some books on top of the 6300 to 

Also, if you know me, I'm one to try it out and see what happens.  I was long taught by Hams and Managers ... try something.... failing is a learning experience.

For 2 years, I had a 6300 see some pretty cold temperatures and it worked just fine.  

The 6300 was replaced with a 6600 for this winter.  In fact, the lake froze a year earlier than normal and with the ground freezing it moved the resonance of my 160M inverted L up enough to be a problem on the ARRL 160 cw test.  

So far, I have seen surrounding air temps in the shack down to about 0C which is reported by my RemoteQTH server.  And, without the insulating cover on the radio FRSTACK was also reporting the same temperature in the radio.  This was getting me worried in case the radio had an issue.

I gave it some thought and went to Home Depot, picked up some 1" styrofoam and built a cover that would cover the top, sides and front and hot glued it together.  Nothing fancy.  (sorry no pictures -- just build a styrofoam house that will go over a radio :) )

I cut out the vent holes on the side and didn't cover the back at all.  After all, the radio does generate some heat and I wanted to save some.  I also wanted the fan to move air should it have to come on.

The results is pretty good.  Static air temp is about 12-15C, and I can drive that up to 30C if running 100 watt of RTTY, FT8 or MSK144.  All within spec.

I'll report back in January when it gets really cold.  I am sure that Marc VE2OLM has some similar stories with his EME site that he has had for years.

Mike va3mw
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Michael Walker, Employee

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Posted 1 week ago

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Jim Gilliam

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Like anything with fans, they are mechanical. If it weren't for the fans, I would leave my radio on 24/7.
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John - AI4FR

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Thanks for the post, I found it different than the usual and interesting. We have the opposite problem down here in Florida but I wish you the best of luck with your experiment. Sounds like you are on the right track.
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Michael Walker, Employee

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I am not worried about the fans at all.  If they fail, they are easy enough to replace as it is 1 big fan in the front.  
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Mark - WS7M

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Michael,

Thanks for the post.   I have long been a proponent of leaving electronic gear on 24/7.  As far as fans go, as a pilot, I bored holes in the air with big fans on either the front, back or both sides.

It was my experience, granted those fans are quite different, that problems occur mover 90% of the time in the transitional states.  IE once up to speed fans generally just continue to run.  The real wear and tear on moving parts is the startup and shutdown.

In my years as a pro-pilot, early years in piston and turbo-props, ALL engine failures occurred during transition to more power or less.   I never had a failure at constant power/speed.

I will say that with respect to very cold temps if the grease used in any fan bearing is not cold resistant that you will have problems.  That is why I like your box idea.  I try to ensure my radio shack which is shared with an HVAC unit remains above freezing.
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Michael Walker, Employee

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I have a PA28 with 2800 hrs SMOH on the engine.  If I never had to shut it down ... LOL
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Richard McClelland, AA5S

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I was in a 1958 Beech Bonanza v-tail and it had an engine failure at constant speed -  the fuel pump failed.  My oldest brother was flying and I immediately knew the engine had quit because the pitch of the propeller noise changed suddenly without my brother touching any switches or dials.  I didn't say anything as I watched him go through his 'Oh, Dear!!!" checklist.  He eventually found the backup hand operated fuel pump and got us to a nearby airport.     
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Steven Linley

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The shack itself, how are you keeping the critters out?
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Michael Walker, Employee

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For this winter, I don't.  They don't touch much and the worst part is that you need to keep the mice from crawling into computers or the Flex.  Good screening on all vents.  That being said, the building is not critter proof.  Hasn't been an issue in 15 years.
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Mark NS9N

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Hi Mike, there for sure is some great advice about mechanical parts like fans, knobs, and buttons but at the cold temperatures you are discussing the fan will most likely never come on. And it sound like you won't be in the room twisting knobs or pushing buttons. OF course you need to keep the critters out. That would be my biggest concern once the radio gets warned up. They love a warm place in a cold room.

For the rest of the electronics, besides making sure the crystal reference oscillator is stable and on frequency and the radio has warmed up to within the specified operating temperatures, you should have no worries.

I have been doing Automotive electronics reliability for 40 years and with today's technology deployed in both consumer and automotive industries, surviving - 40 is not an issue for storage range and I have yet to see a catastrophic failure due to this temperature without something else being the root cause.

Said another way, after looking at my Flex 6600 circuit boards, well done Flex. Very clean and reliable design.

Now performance over temperature is an entirely different issue. It really comes down to the specified operating temperature range of the components. And this appears to be well covered by the operating temperatures specified by Flex for your radio. Will it work outside of the specified range, maybe. Will it be damaged trying to operate outside of the temperate range going colder, electronic history says no down to - 40. You may have to power cycle it when getting back within the operating range but that usually returns every thing to normal.

The same type of PC boards and solders are used in engine controls and if they will survive that environment for 20 years or more, I really doubt you can ever power cycle your radio on and off even 10% what we see in the Auto industry.

Going hot is an entirely different story. Do not exceed the recommended operating range by the manufacturer or you do risk a catastrophic failure. Oh sure, some will say there is always design margin, but finding out how much is not worth your risk.

One last concern, humidity in the room before things get cold. Condensing moisture is an electronic units worse nightmare. As the room temperature goes up and down, so does the dew point. The only true way to prevent this issue is to keep the radio warmer than the surrounding air. Power it on and leave it on and all these worries go away.

Enjoy operating in a cold environment. Some may say it is much easier then hot and humid.
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Michael Walker, Employee

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I have yet to worry about humidity as a problem, and yes I have to deal with it.  We do get from 15% to 100% and while I hear of  concerns, it has yet to be an issue in over 15 years.  I have seen corrosion from standing rain water, but that is not part of this problem.    It would be very very seldom that the device is colder than the surrounding air.     

Here is why I don't worry about this too much.  In my R/C Plane world, I fly a lot of Float planes and they get drowned more than often.  The receivers and speed controllers are sprayed with a conformal coating and that makes this an non-issue.  I have drowned many a plane.  Drained the water out of it, and flown it seconds later.  Servos have a product called Corrosion X injected into them (essentially an oil).  Most of these planes have been flying for many years with limited maintenance.

For the most part, fresh water has a very high impedance and as long as you don't have a corrosion issue, it will not affect most items on circuit boards, other than anything water molecules can actually get into such as Displays, Electrolytic Caps, pots, speakers, microphones.  

Short story, there isn't much I can do about humidity practically and so I don't worry about it.  Case in point, I just brought home the KPA500 that was there for about 7 years and opened it up.  Other than some dust there is zero corrosion on any connector and no other sign of humidity being a problem.  Now, in a Salt Air environment, that is a different issue.
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Tim N9PUZ

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As for "critter proofing" the electronics, one place I worked years ago we protected some remote electronics by enclosing it in a cage that was fabricated out of some metal screen  openings that were about a quarter inch square. It provided virtually no airflow restriction but did a good job of keeping rodents, etc. out of the equipment. Prior to the cage the warmth of the equipment would occasionally attract snakes that liked to curl up inside. That made the technician's lives more interesting than they liked!

Tim N9PUZ
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Bob

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I also do remote operating with 6600 and Acom 660S and desktop with SSD to monitor Amp I use Reflectix which is about 1/8 thick and has some insulation properties. The insulation is mounted over the top of my operating desk. It is simply sealed with you guessed it with Duct tape.  I purposely left some openings  for vents. The cost of a 2' x 25ft roll was 20 dollars. This has worked well thus far as I turn off all heating at our QTH in northern ,WI where it was -2 last night. The 6600 and desktop are always on.

Bob KC9RF

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Michael Walker, Employee

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It doesn't take much to keep things warm.  This is my insulated cover.  The back is not covered.