The WORKBENCH part 3

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Roller coaster temperatures in the garden shed…
(Green line)
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Think your temp sensor is faulty, looks like it’s stuck, it doesn’t work above 20C. This is what a temp graph should peak at
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Yesterday one of my students got enthousiast. He really wanted to get connected to TTN so he built an antenne while I modified the node for him. Joint effort by student and teacher! We measured and tuned the antenna to 868 MHz in IoT class. #Fun!

20190319_195202 VNA_190319_185616

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1.02 SWR :open_mouth: … you’re a master tuner

these arrived here yesterday

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@gmos

@TonySmith please show us your enclosure :smiley:

@slaven96 Here you go, the enclosure is cylindrical with the cable entering at the top so it hangs from the cable. There are two cylindrical walls with the slots on the inner and outer walls which are offset. A spray of water cannot get directly on the sensor. The bottom has holes to drain any water that enters through the slots in the outer wall. Actually just realised I don’t have many good photos of the enclosure. Will need to take some next time I’m on site which by the way is ~400Km away.
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a friend’s PC that started smoking… it seems the (expensive) videocard :sob:

yes/no/yes/no/yes/no/yes/no/ YES :sunglasses:

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Works like a charm. And when using the software on your computer, you can extend the measurement range up to 1.4Ghz.

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win 10 ? I guess yes, manufacturer website says ‘window drivers’

Have received mine yesterday @BoRRoZ . Attached one on a sheet of metal (old DVD internal drive) with the built-in magnet and connected it to the analyser.
Wee bit above 50 ohms and SWR of about 1.5. Have seen them a lot worse.

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IMG_1880

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all parts finally arrrived… now see if I can get a usable wireless image on an RPI

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no worries… cheap jammers don’t work :wink:

Cooling fins clogged with dust?

Possible … I have seen real smoke and something smelled burned inside that card, capacitor ?
don’t know… he couldn’t wait for a repair and went straight to a nearby shop for a new one, computer worked again and he left the old card here 'to ‘fix’ / sell, I didn’t had time to look at it further :sunglasses:

Speaking about capacitors and smoke: I made a minor mod to my (old) car radio yesterday for which I (also) added a small step down converter to power a 5V bluetooth receiver. As extra I added a 470 uF capacitor to the converter’s output. I rotated one of it’s legs a bit to make it fit more nicely (which probably made it shortcut internally, which I only became aware of after powering it…).

When switching the modded radio on the capacitor exploded with a bang and smoke was coming out on all sides of the radio. The fragments (mainly paper fibers) had ‘nicely distributed’ inside the radio (but were easy to clean luckily).
The radio survived, but the converter and bluetooth receiver did not. Output of the step down converter was now the same as it’s input, 12+V (which the BT receiver could not handle). :roll_eyes:

Lesson learned: never rotate the pins of an (electrolytical) capacitor - not even a tiny bit.

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really happy to hear the doorbell ring… is was not the antenna analyzer but the tiny 44,- euro lab power supply 0-30v 10A :rofl:

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first impression… not bad :wink:
I’m gonna use it as a ‘dedicated’ LiPo battery charger

ohms
:rofl:

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