Cold Temperature Testing Your Rigs.

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w0rw
Posts: 30
Joined: Wed Nov 16, 2022 5:27 pm

Cold Temperature Testing Your Rigs.

Post by w0rw »

Cold Temperature Testing Your Rigs.
See details here:
http://tinyurl.com/3ekaanw3
Has anyone tested the KH-1 yet?
Paul w0rw
Colorado
W5OTR
Posts: 5
Joined: Wed Jan 10, 2024 5:30 am

Re: Cold Temperature Testing Your Rigs.

Post by W5OTR »

This is a good time for it-- nearly everywhere
N8TGQ
Posts: 66
Joined: Tue Jun 21, 2022 5:06 am

Re: Cold Temperature Testing Your Rigs.

Post by N8TGQ »

I know mine work down to 50°. Below that, I don't work!

The link you provided requires membership, so not able to check it out.
Rick N8TGQ
w0rw
Posts: 30
Joined: Wed Nov 16, 2022 5:27 pm

Re: Cold Temperature Testing Your Rigs.

Post by w0rw »

Here is the information, The link apparently doesn't work.

“Cold Temperature Testing Your Rigs”
When you are going to be out in the field for Winter Field Day, SOTA, POTA, FYBO (Brrrr), or Polar Bear (Grrrrr) operations you want to make sure your rig is still going to work in those cold environments. You don't want to travel out to some freezing wilderness to find your rig won't transmit or have to wait for the power to come back on in your shack to make sure your rig still works.
This Cold Testing qualification test is a Slow Thermal Cold Soak, not a Fast Thermal Shock test.
(Thermal Shock can crack solder joints, you don't want to do that).
At the start of this test I measured and recorded the room temperature characteristics of my radios prior to the test. Measuring RF Power output, Frequency accuracy, keying (chirp), receiver sensitivity, battery voltage and Voltage drop during transmit, etc.

Then I waited for one of those cold winter nights. i put the rigs in my car overnight for the cold soak. Some of my rigs have Commercial parts in them, and some have Military temperature range parts in them that are good down to -30F.

i tested the "1 Watter" 1W20 first, It is refitted into an old military radio chassis. It passed - 6F.

It is nice to have a rig that has big knobs for gloved operation in cold temperatures.
Some radios have small switches that are hard to get at with gloves on but once set, gloves can still be used.

Then i put my PRC64, PRC74, PRC319, and Elecraft KX1, outside for an overnight cold soak at -10F. The next morning i re-measured all the characteristics and looked for LCD display errors on the PRC319. They all passed. The test did spot some limiting accessory issues: Some cables were not mil spec and bending them could crack the insulation, Some controls got very hard to turn, One commercial switching power supply would not start, Some batteries were not as good as I had thought they would be, 50% lower capacity.
(This cold testing can be very expensive if you find a failure. One of PRC radios had LCD Digits in the display missing. It could not be fixed. That radio was sold to a museum. i couldn't sell them an out of spec radio without telling them and giving a big discount. i lost $750 on the sale.)

Then i brought the radios back up to +60F in a low humidity room with the power removed to prevent dendrite growth.
You don't want the radios powered on as they go through the dew point.
You should not do this kind of testing using your home freezer because that could cause Thermo Shock damage. i wouldn't recommend any Thermo Shock (Quick Freeze) testing unless you are prepared to fix your radio.

Now all the radios are qualified i am ready to go.
Some have asked "What about the operator"? Well when it gets really cold I use my WW2 US Army Air Force 'F-1' Heated Bunny Suit that was used in B25's, etc.
It is like an electric blanket but in a zippered jump suit style. It runs on a 12V battery.
Heated Motorcycle apparel is also available.
This is my active cold weather gear.
I also use a ‘Key Muff’ made out of an old rug for my CW paddle.
i also use half gloves for sending CW.

Paul w0rw
Snowy Colorado
N8TGQ
Posts: 66
Joined: Tue Jun 21, 2022 5:06 am

Re: Cold Temperature Testing Your Rigs.

Post by N8TGQ »

Thanks for the update, Paul!
Rick N8TGQ
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