Soliton Water Cooling Update – and the MKARS80

HNY to all and sundried, I hope this year is better than last, not that I really celebrate the passing of a construct let alone an integer (but any lame excuse will do for a party). For my electric vehicle (leaving MKARS80 aside for the moment), all is going well, very little maintenance, until my Thermaltake water pump failed (supposedly guaranteed for 80,000 hours – my ass). This is used to cool the IGBTs in the Soliton 1 motor controller. Thankfully this situation was an opportunity for improvement; I purchased a cheaper (and better pump) off eBay and Rod found his unused oil breather tank and this is now the reservoir replacement for the bodgy plastic bottle that was there before.

Now that my system is pressurized; there is not much force in the entire system and under test everything flowed well and connectors did not leak. This set up is definitely better than the old one. There is even a level indicator. I highly recommend this type of reservoir if you plan to install water cooling for your electric vehicle motor controller.

New water cooling reservoir no longer a dog

The MKARS80

Fully digressing here, a radio project, so feel free not to read further if you are only interested in electric cars…

On to other matters both geeky and retro, I took some spare time to finally build a MKARS80 lower sideband qrp transceiver for the 80 meter band (this is a project from the Milton Keynes Amateur Radio Society). This has been a real fun project, assembling the components on the pcb was relatively simple even though one capacitor was missing which caused a quick drive to the local Jaycar in the pouring rain (I have virtually every other value ceramic in my junk box except the one I wanted – isn’t that always the way??). And despite what some friends said, I don’t see any problem winding my own toroids. The radio employs a PIC and uses ‘huff n puff’ stability which takes a little time to settle after warm up. This is a proper LSB radio, not a dsb (double sideband) that some other qrp projects have. Having no smd components meant construction was kind to my eyes.

The basic radio is pretty low budget and doesn’t have an AGC so I may add one later (there are a few mods sites with agc details, and substituting the polyvaricon, different mounting configurations etc). I added a couple of my own mods including an internal speaker, an s-meter circuit I made up on separate vero and an internal battery pack. Rod and I sat down and designed a new case for it in SolidWorks and I had this bent up and powdercoated for a reasonable cost. Everything fit nicely though if I redesign the front decal it will look considerably different.

Mounted mkars80 pcb inside new custom-made case

mkars80 with added s-meter board (for analog s-meter) and internal eneloop batteries

Finished mkars80 LSB Transceiver with matching Starion red color :)

Initial contacts gave good signal reports even on 3 watts, beating some others on a hundred watts (which only goes to prove that a good antenna is almost everything), and this particular radio design always results in good audio reports. This will be a great qrp (low power) radio for the field. A friend wants me to make one for him, hah, maybe if time permits (and I don’t start building the mkars pic-a-star), though this project was a lot quicker to do than the electric vehicle!

Stay well,

Carmel