FlightAware Discussions

Pro Stick Plus works at -40 degrees


#1

As I write, the outside air temperature is -40 degrees Celsius outside and the Flightaware Pro Stick Plus up on the roof is still functioning. Here in Canada we measure temperature in degrees Celsius, however -40 is the temperature at which the Celsius and Fahrenheit scales cross, so no matter which scale you prefer, it’s still -40 outside. Fortunately, there is not much wind at the moment so the wind chill is ‘only’ -51C.

The dongle is plugged into a tiny Nexx WT3020 running OpenWrt and Dump1090-mutability, and between the dongle and the antenna is an LNA4ALL and a ceramic filter from Adam (9A4QV). The whole kit is mounted on the roof inside a 1/4 inch thick aluminum box, which is further protected by a poly amunition box. The antenna is a Heliax colinnear, with about 20 feet of 1/2 inch Heliax Superflex to the box.

Noise levels appear lower (min -42db), and sensitivity seems to be higher - more distant positions.

Yxespotter - Saskatoon, Canada. CYXE


#2

I’ll bring up adding “Tough enough to handle a Canadian winter!” to the Pro Stick Plus description at the ADS-B Team meeting. Thanks for letting us know and stay warm!


#3

The standard temp ranges for ICs are -40C to +125C for Automotive, -40C to +85C for Industrial, and 0C to +70C for Commercial (e.g. chips in TV sets).
Luckly the dongle runs hot and provides some temperature to keep the IC plastic housing from cracking. In some professional electronic devices installed outside, there are provisions for heat tracing.
Worse is the case of summer ambient heat.

That’s why I don’t recommend installing the electronics outside, but rather running a coax cable to an indoor location where all of the active devices would work.
The only thing that should be outside is an amplifier/filter.


#4

There is a small nuance - at what minimum temperature an electrolytic capacitors are damaged.


#5

Depending on which one they use. Commercial or industrial, they come in both versions, money difference.
But even the IC’s can be mechanical stressed by low temperatures and break the hair - thick connections inside.


#6

The ProStickPlus may be OK here in the cold, but the Pi3 that it’s connected to in my shed outside is not surviving our recent low temperatures - been in the single digits (Fahrenheit) (-15 to -25 Celsius) here in So Dakota and the Pi3 simply stopped working. LEDs in the ProStickPlus and Pi3 are still on, but no ‘computing’ is going on. Reboot works for a while, then stops. So it goes…


#7

“Worse is the case of summer ambient heat.”
Indeed. Although in the shadow of the house during the day, by evening the box was in the direct sunlight and the temperatures inside the box were climbing to a dangerous level. A sunshield made from aluminum sheet painted while, positioned a foot or so away from the box, solved the problem and dropped the internal temperature back to something more reasonable.

In the winter, the same sunshield serves to alter the wind pattern on the roof, keeping the box protected from snowdrifts that would otherwise encase it.


#8

Update…just before 9:00am this morning, we bottomed-out at -43C with a windchill of -53C, not quite a new record low, but starting to get close.
Apparently this cold weather is to continue for a few more days.


#9

Luke Skywalker Enjoying A Ride on Tauntaun in Saskatoon, Canada at -51°C

Luke_Skywalker_riding_Tounton_in_Canada


#10

There is an article in Russian about testing Raspberry Pi in conditions of severe frost

At temperatures below -35, the RPi 3 board and temperatures below -45 RP, the RPi 2 board stops running (does not start).

In another article about Rpi freezing https://habr.com/ru/post/178647 /#comment_6200633 is a comment

When we developed a printed circuit board for street conditions, we took a minimum operating temperature of -50C, at this temperature an electrolytic capacitors stopped functioning after 4 hours. We had to fight current ripples in a different way…


#11

Solid-Electrolyte Tantalum capacitors.
Industrial grade, -55C…+125C:



Automotive grade, -55C…+200C:

Source: https://www.vishay.com/capacitors/tantalum/tantalum-solid/

However, for low temperatures we (engineers) add thermostat-controlled heaters inside the electronic boxes. Cheaper.


#12

PoE standard provides up to 50W. But usually 15W. The question is how much heat loss the box on roof has. On the other hand - in summer there may be overheating


#13

Those are PTC, self limiting at higher temperature.


#14

I meant that for the operation of heaters the heat insulation of the case is necessary. In the summer, a situation may arise in the need for cooling inside the case.


#15

Not really. On that website is a way to calculate the power required to heat, without insulating the box.

But, again, the best is to keep the electronics inside the house, run a coax cable between antenna and receiver. The only thing that needs to be outside is an amplifier/filter. Those are simple enough and do not need to use any electrolytic capacitors.


#16

In the case of a cable 50 meters long, I would prefer to transfer a digital data. The choice of LNA and filter parameters is a difficult question.


#17

My cable is that long. An amp/filter fed via T-tap it’s all I needed.
I don’t have to worry about my $99 dongle and the $45 Pi3+SD card getting damaged by weather.

More than one way to skin a cat.