FX-4CR: Thermal images and firmware update...KX2 on the way

Robin Davies G7VKQ was kind enough to give me permission to post thermal images of his FX-4CR, made with an InfiRay P2 Pro plugged into his iPhone.

From Robin:

I received my FX4CR recently, and I have been learning a little about the rig (but not used it in anger yet). As part of my learning I have successfully got the Bluetooth connection to FT8CN working and update to the 1.4 firmware. I have also being playing with some new data acquisition toys (an Openlog Artemis and some thermocouples).

I’ve run this test a few times now and I think my measuring technique has improved - so feel this is the most accurate measurements I have made to date. I ran a soak test this morning with around 55 minutes of calling CQ on FT8 (at 5W) every 30 seconds and then let the rig cool for 10 minutes at the end.

10 suggestions for FX-5; 10 things I like about the FX-4CR

 

10 suggestions for improvement for FX-4CR (or a future FX5):

• Topography redesigned so that heat sink can be external to rig (rather than encased internally), ideally occupying the entire rear panel. As it is now, every component within the radio is heated.
  
• T/R switching performed in such a way (reed relay?) that its functionality is not affected by CW speed. There should be no interaction between CW speed and T/R delay setting
• Fix the intermittent issue where RF is generated (Morse characters) and outputted properly, but sidetone for that RF is missing. This occurs infrequently and is probably related to the above issue
• Fix audio artifacts issue on CW that frequently occurs during transmit. The only audio produced during transmit should be the sidetone.
• IF filter selections should become narrower, not wider, as selection button is toggled. We "drill down" to the signal of interest, not back away from it.
• Owner's manual should include schematic - or at least a block diagram
• Owner's manual should include complete alignment procedure. Users should not need to be Facebook members to have access to this info
• Have 3 or 4 experienced ops (CW, SSB, digital) beta-test the FX5 before offering it for sale
• Fix issue where unplugging headphones does not re-route audio to speaker w/o having to power cycle the radio
• Continue with open-source firmware

10 Likes:

• Responsiveness of Yu BG2FX
• Excellent receiver characteristics - atypical for this price class. Sharp skirts and no ringing down to 100Hz (a bit at 50Hz) - fantastic!
• Excellent audio fidelity from built-in speaker on CW, SSB and AM-SWL
• Solidity of construction, use of flush-type allen screws
• 6-80m operation with 20 watts out (on 10-80; 5W on 6m)
• Switchable from ham transceiver to SWL receiver with bands selectable
• Included accessories (hard case, mic, spare fuses, USB cable, DC cable with inline ferrite core)
• Bright, colorful, easy to read (even in sunlight) display
• Accuracy of useful info displayed (DC supply voltage, SWR, RF out - all spot-on)
• Ergonomics: all of the most-needed controls are easily & quickly accessible. 'Menu' is only needed for rarely-accessed functions

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POTA with FX-4CR - monitoring its temperature on a hot day

This video will probably be of limited use in determining the heat dissipation characteristics of the FX-4CR - but several people have commented on the radio's tendency to become very hot over the course of an operating session, even when operating CW at 5 watts.

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.