In this video, I'm on CW at full output - 20 watts. In 30 minutes, the radio's case is 25F/14C above ambient. I cut the video short at that point since a mower started up. Florida must have the best-mowed parks in the US.
The video is only 10 minutes long since I edited out most of the parts where I'm answering stations or calling CQ.
If I'd continued operating at a POTA-type duty cycle, the temperature would have continued to rise. I know this from previous sessions on the air. The solution is to take breaks in the operation and to realize that this is a very small radio with a 20W output - a larger radio would run cooler; a smaller one would be even hotter.
This is a matter of thermodynamics, not of poor design - users just need to be aware of it and know how to mitigate it (lower power and/or reduced duty cycle).
These "laptop cooling feet" might help with improved air circulation but the heatsink is sealed within the FX-4CR.
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| The heatsink is the thick metal slab on the right-hand side |
It's also important to realize that, when not operating at a high duty cycle, this is a 6-80m all-mode rig that provides 20 watts in a tiny package. There is nothing else like it on the market. And it's also a SWL receiver with good fidelity on AM.
There are, however, keying issues associated with this radio and I'll elaborate on them in a future video.
An infrared thermometer was used to confirm what the adhesive strips were telling me and to get better resolution than the 5C-degree steps of the strips.
About the strips: I'm a believer!
They are not only accurate but fast-acting in both directions of temperature change. In tinkering with them around the house, indoors, in the car, in front of an A/C vent, etc - they react quickly to temperature changes and the indicated step is correct.
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Love how you got to the park! I do the same thing when I can :)
ReplyDeleteNick
KC0MYW
I'm looking to do more of the same once summer is over - lots of fun!
Delete73,
John
As you mention, only so much can be expected from these little rigs. It's a great little rig, and Yu seems to be very proactive in addressing shortcomings via firmware. I did some temperature monitoring tests with mine, and gathered some data which I've just posted on twitter (https://twitter.com/rdavies6/status/1682347520960217089?s=12&t=sXSZTkef46Exzv3TY6qTIw). I'm impressed the cooling cycle of the enclosure can just about be seen,..I should maybe have taken more frequent temperature samples to get a more accurate view
ReplyDeleteThanks for the info, Robin. What are you using to measure the temp and plot the graph?
ReplyDelete73,
John
I am using a Openlog Artemis from Sparkfun to grab the data - such a cool little device (I bought it as a way of grabbing serial data from little MCU boards that I'm running programs on). I extended it with their Qwiic Mux board to allow multiple sensors with the same I2C address to be daisychained. I am using two thermocouple boards and Type K thermocouples to get the case temperatures, and the Openlog board's own temperature sensor for the ambient reading. There are quite a few additional sensors you can add to the Openlog Artems -and it's quite a cheap way of getting some quite interesting dataloging. The board logs to a microSD card and in this case I'm powering it via my laptop's USB. I then download the readings to the laptop via the USB connection and I'm processing the CSV logging data and creating the graph images with a small 20 line program in R (which I run in an environment called R Studio https://posit.co/products/open-source/rstudio/ ). I took temperature readings every 30 seconds...but probably needed to take a reading every 5 seconds to get a better profile of the heatsink heating up and then cooling.
ReplyDeleteThat's pretty interesting - now you've got me surfing Sparkfun again...it's been a while.
DeleteI found these dual channel thermometers during the search for my adhesive thermal strips:
https://amzn.to/44BczH2
I may get one yet - they're cheap enough - but would like to find one that will graph the temperatures over time.
Lol! That's exactly the logic that lead me to the Openlog setup :). The idea I could log between thousands of events per hour or just one event per day over many months, and have it safely stored to microSD was very appealing! You could graph the data via Excel or any number of other software products. I just chose R as I want to learn about it a little more...and I quite like the quality of graphs it can create
Delete