#electronicsengineering

Søren KjærsgaardSo when you have a bunch of jellybean JFETs (2N5457), time to burn, and a handful of 1uF bipolar capacitors… What to do.. 🤷🏼‍♂️🤓I decided to build a simple amplifier 😃 Although many find JFETs aren’t quite as intuitive as a regular BJTs, they’re not THAT scary 👻😂 and they’re easily biased, using a megaohm sized resistor from the gate to ground. To be able to do some more accurate calculations, I decided to measure the maximum drain current, IDSS, and the negative Gate-Source cut-off (pinch off) voltage, as they can vary significantly even between devices even from the same batch. A fun evening in the lab 😃<a href="https://techhub.social/tags/electronics" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#electronics</a> <a href="https://techhub.social/tags/rfengineer" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#rfengineer</a> <a href="https://techhub.social/tags/electronicsengineering" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#electronicsengineering</a> <a href="https://techhub.social/tags/EE" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#EE</a> <a href="https://techhub.social/tags/testandmeasurement" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#testandmeasurement</a> <a href="https://techhub.social/tags/hamradio" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#hamradio</a> <a href="https://techhub.social/tags/hamr" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#hamr</a>

Søren KjærsgaardThis weekend was special: yesterday the baltic countries: Estonia, Lithuania and Latvia, disconnected from the Russian/Belarus 50Hz power grid, going ‘island mode’, controlling the 50Hz grid frequency themselves. After more than a day of different stability tests, this afternoon, just before 13:00 CET, a connection to the European grid was established via Poland, so now the the three countries are in 50Hz sync with Europe. I observed a small, undramatic, ‘burp’ in the frequency at the time of the event, and my wall socket is now in full sync with the measurement in Estonia, provided by <a href="https://techhub.social/tags/sympower" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#sympower</a>⚡️ 😃👌🏼<a href="https://techhub.social/tags/gridtech" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#gridtech</a> <a href="https://techhub.social/tags/powerdistribution" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#powerdistribution</a> <a href="https://techhub.social/tags/electronicsengineering" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#electronicsengineering</a> <a href="https://techhub.social/tags/testandmeasurement" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#testandmeasurement</a>

Søren KjærsgaardI need a reasonably clean 4MHz oscillator for a <a href="https://techhub.social/tags/hamradio" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#hamradio</a> <a href="https://techhub.social/tags/foxhunt" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#foxhunt</a> offset attenuator and decided to build one based on a J310 J-FET transistor. The output on the Drain is quite clean, but can’t be loaded much, so a I added a simple buffer based on BC547B 🙂It’s all pretty standard circuitry, and you can find all kinds of variants out there, but it’s still fun to see it spring to life 😃<a href="https://techhub.social/tags/hamr" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#hamr</a> <a href="https://techhub.social/tags/testandmeasurement" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#testandmeasurement</a> <a href="https://techhub.social/tags/rfengineer" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#rfengineer</a> <a href="https://techhub.social/tags/electronicsengineering" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#electronicsengineering</a> <a href="https://techhub.social/tags/siglent" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#siglent</a>

Søren KjærsgaardMy first <a href="https://techhub.social/tags/HB9CV" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#HB9CV</a> <a href="https://techhub.social/tags/antenna" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#antenna</a>, believe it or not, made from 5mm brake lines and a foot of 15mm copper pipe 🙂I need it for a 70cm radio <a href="https://techhub.social/tags/foxhunt" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#foxhunt</a> event in a couple days - looked different places for design guidelines, some of them came up with quite different results 🤷🏼‍♂️🤨Decided to just have go at it, based on a combination of what I could find in the legendary <a href="https://techhub.social/tags/Rothammel" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#Rothammel</a> antenna book and some online sources and it turned out quite well 😃Resonance is a bit low, 431MHz, but it’ll do fine as a direction finding device: what I really want is the characteristic kidney shaped radiation pattern, allowing me to turn the antenna backwards, looking for a minimum in the received signal. Funny to see how the <a href="https://techhub.social/tags/smithchart" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#smithchart</a> impedance plot has a distinct turn at the resonance frequency 🤓<a href="https://techhub.social/tags/rfengineer" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#rfengineer</a> <a href="https://techhub.social/tags/hamr" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#hamr</a> <a href="https://techhub.social/tags/antennadesign" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#antennadesign</a> <a href="https://techhub.social/tags/testandmeasurement" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#testandmeasurement</a> <a href="https://techhub.social/tags/electronicsengineering" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#electronicsengineering</a>

Søren KjærsgaardBeen debating a loooong time whether to get the SV4401A 4.4GHz VNA.. I already have a 4GHz NanoVNA, but the display size, ruggedness and N-connectors on the 4401 is a major upgrade.. Well, I took the leap! 😃And why not make the first-light ‘Hello, World’ test a fun one ☺️ I came across an AT-741 aircraft IFF transponder antenna and it seems like it still works 🙂Still in production by several vendors (fx Harris), the unit I have is old, dated 08/1979. So much more fun to have it sense a bit of RF so many years down the road 👍🏼<a href="https://techhub.social/tags/rfengineer" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#rfengineer</a> <a href="https://techhub.social/tags/hamradio" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#hamradio</a> <a href="https://techhub.social/tags/testandmeasurement" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#testandmeasurement</a> <a href="https://techhub.social/tags/measurementmonday" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#measurementmonday</a> <a href="https://techhub.social/tags/electronics" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#electronics</a> <a href="https://techhub.social/tags/electronicsengineering" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#electronicsengineering</a>

Søren KjærsgaardYay! 😀 The 432A power meter works just fine and I managed to scavenge some probes and the needed connection cable - my first calibrated power meter ever 🙂What a beautiful addition to my little lab 🥳🎄I have more probes and together they cover all the way to 18GHz 👍🏼<a href="https://techhub.social/tags/hamradio" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#hamradio</a> <a href="https://techhub.social/tags/hamr" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#hamr</a> <a href="https://techhub.social/tags/rfengineer" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#rfengineer</a> <a href="https://techhub.social/tags/testandmeasurement" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#testandmeasurement</a> <a href="https://techhub.social/tags/electronicsengineering" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#electronicsengineering</a>

Søren KjærsgaardOccasionally you come across a rescue scenario: it was literally me or the dumpster… So I adopted it, I now have a 20GHz frequency counter… 🤷🏼‍♂️😎The 5361B was never made for normal RF use, its primary application is analysis of pulsed radars. It does, however, fully support CW measurements, so although somewhat bulky, it’s a nice instrument to have around in the lab 🙂<a href="https://techhub.social/tags/testandmeasurement" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#testandmeasurement</a> <a href="https://techhub.social/tags/rfengineer" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#rfengineer</a> <a href="https://techhub.social/tags/electronicsengineering" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#electronicsengineering</a> <a href="https://techhub.social/tags/hamradio" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#hamradio</a> <a href="https://techhub.social/tags/hamr" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#hamr</a>

Søren Kjærsgaard<a href="https://techhub.social/tags/Metrology" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#Metrology</a> friends, any good suggestions for a gold plated banana jack? I found these from QED, they look promising 🙂 <a href="https://techhub.social/tags/electronics" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#electronics</a> <a href="https://techhub.social/tags/electronicsengineering" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#electronicsengineering</a>

Søren KjærsgaardSo there’s a new instrument in the lab… I finally got a 6.5digit bench DMM 😃It’s nice to have a precision unit which only takes an hour to warm up, unlike my 3458A which takes 4hrs 😳 And having the possibility to plot trends is really nice. My Siglent has found a new home and a happy owner, all is good 😊 <a href="https://techhub.social/tags/testandmeasurement" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#testandmeasurement</a> <a href="https://techhub.social/tags/electronics" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#electronics</a> <a href="https://techhub.social/tags/electronicsengineering" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#electronicsengineering</a> <a href="https://techhub.social/tags/rfengineer" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#rfengineer</a> <a href="https://techhub.social/tags/hamradio" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#hamradio</a> <a href="https://techhub.social/tags/metrology" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#metrology</a>

Søren KjærsgaardRemember the vintage 1958 Weston voltage standard cell from back in August? Well, I left it alone to stabilize and recover from whichever faith it came from and looksee here: a perfect 1.018248V, right at the lower boundary of its specifications 😃🔋 The small label, dated Feb. 1958, says it measured 1.0194V back then, so basically it dropped just 17uV every year the last 66 years 🤯 That’s amazingly stable 🤷🏼‍♂️And look at the steady readout - not much noise there, it’s incredible. What’s next? Not much I guess, but it’s definitely a fun thing to have around 🙂<a href="https://techhub.social/tags/metrology" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#metrology</a> <a href="https://techhub.social/tags/electronics" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#electronics</a> <a href="https://techhub.social/tags/testandmeasurement" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#testandmeasurement</a> <a href="https://techhub.social/tags/engineer" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#engineer</a> <a href="https://techhub.social/tags/electronicsengineering" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#electronicsengineering</a> <a href="https://techhub.social/tags/hamradio" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#hamradio</a>

Søren KjærsgaardGot an offer I couldn’t reject, and now I’m at a stage, where the multimeter game is over - not much to do and improve from here - except play with my new toy 🤷🏼‍♂️🙂🙂<a href="https://techhub.social/tags/electronics" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#electronics</a> <a href="https://techhub.social/tags/electronicsengineering" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#electronicsengineering</a> <a href="https://techhub.social/tags/rfengineer" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#rfengineer</a> <a href="https://techhub.social/tags/hamradio" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#hamradio</a> <a href="https://techhub.social/tags/hamr" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#hamr</a> <a href="https://techhub.social/tags/testandmeasurement" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#testandmeasurement</a>

Søren KjærsgaardI needed a simple code lock for this years <a href="https://techhub.social/tags/jotajoti" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#jotajoti</a> <a href="https://techhub.social/tags/scout" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#scout</a> event - won’t reveal why just yet 🙂Everything these days revolves around microcontrollers and sure, easy to do, however I needed simplicity and 9V battery power, outside at potentially freezing temperatures and it also needs to be low cost, I plan to use at least three of them.. Came across this simple circuit, almost too simple to be true, but it does the job just fine: push the four buttons in the right order and the output is enabled. Bingo 😃Not overly secure but for my purposes, it’s a perfect little vintage code lock 🔐👌🏼☺️<a href="https://techhub.social/tags/hamradio" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#hamradio</a> <a href="https://techhub.social/tags/electronics" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#electronics</a> <a href="https://techhub.social/tags/electronicsengineering" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#electronicsengineering</a> <a href="https://techhub.social/tags/vintage" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#vintage</a> <a href="https://techhub.social/tags/cmoslogicfamily" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#cmoslogicfamily</a> <a href="https://techhub.social/tags/cmos" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#cmos</a> <a href="https://techhub.social/tags/digitaldesign" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#digitaldesign</a> <a href="https://techhub.social/tags/jota" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#jota</a> <a href="https://techhub.social/tags/joti" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#joti</a>

Søren KjærsgaardWhat a score - genuine EPPLEY voltage cell, originally used for calibration purposes. Even though it’s 66 years old, it still seems to work, it’s amazing 🤩 Stay tuned for a more thorough test under more controlled climatic conditions 👍🏼<a href="https://techhub.social/tags/vintage" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#vintage</a> <a href="https://techhub.social/tags/testandmeasurement" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#testandmeasurement</a> <a href="https://techhub.social/tags/electronicsengineering" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#electronicsengineering</a> <a href="https://techhub.social/tags/electronics" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#electronics</a> <a href="https://techhub.social/tags/engineer" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#engineer</a> <a href="https://techhub.social/tags/hamradio" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#hamradio</a> <a href="https://techhub.social/tags/testgeartuesday" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#testgeartuesday</a>

Søren KjærsgaardThe Icom IC-7000 I recently purchased is quite old and they’re known for having a bit of high frequency ‘hiss’ in the audio output. I doesn’t matter while using the built-in speaker, however it gets annoying when using high quality headphones. There is a fix, but it’s complicated and involves extracting a major PCB from the radio.I had some random two-way speaker filter in a drawer so decided to give it a go at reworking it, to become a 700Hz lowpass filter (I’m primarily a CW operator). It turned out really nice, even peaks a bit before rolling off. And the ‘hiss’ from the radio? Gone! 👍🏼😃<a href="https://techhub.social/tags/hamradio" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#hamradio</a> <a href="https://techhub.social/tags/hamr" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#hamr</a> <a href="https://techhub.social/tags/icom" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#icom</a> <a href="https://techhub.social/tags/icom7000" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#icom7000</a> <a href="https://techhub.social/tags/siglent" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#siglent</a> <a href="https://techhub.social/tags/electronicsengineering" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#electronicsengineering</a> <a href="https://techhub.social/tags/signalsaturday" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#signalsaturday</a>

Søren KjærsgaardI’ve been looking for an antenna for a permanent <a href="https://techhub.social/tags/meshtastic" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#meshtastic</a> node in my attic and I found this one, along with 5m RF200 low-loss cable. I know that this setup will most likely render me ‘excommunicado’ in the <a href="https://techhub.social/tags/meshtasticcommunity" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#meshtasticcommunity</a>: “thou shalt always install thy node right below the antenna!”, but here’s the thing: I want to experiment with different hardware, I want to do some interference measurements at night (ever heard about the ‘Mammotion’ lawnmower which illegally jams 868MHz?) , AND I have a powerful 2m/70cm transmitter close to it, and I don’t want EMI issues on a sensitive 5V line. Besides, the antenna has 3dBi gain and I measured the cable loss to 1.4dB at 868MHz, so given its better location, the numbers still come out positive 🙂See that dip near 145MHz btw.? Need to do a test to see how much signal it’ll pick up from my VHF rig - don’t want to damage my LoRa module 👌🏼🙂<a href="https://techhub.social/tags/lorawan" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#lorawan</a> <a href="https://techhub.social/tags/electronicsengineering" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#electronicsengineering</a> <a href="https://techhub.social/tags/rfengineering" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#rfengineering</a> <a href="https://techhub.social/tags/rfengineer" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#rfengineer</a> <a href="https://techhub.social/tags/hamradio" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#hamradio</a> hamr <a href="https://techhub.social/tags/testandmeasurement" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#testandmeasurement</a>

Søren KjærsgaardGetting power from a USB-C adapter may not be as simple as just connecting a cable to it - you need to kindly ask for the power you need ☺️To get 5V@3A it’s as easy as connecting a couple of resistors to the PD (power detect) data lines, however to access the higher power levels available in this <a href="https://techhub.social/tags/IKEA" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#IKEA</a> SJÖSS adapter, you need a small controller to communicate with it.The <a href="https://techhub.social/tags/adafruit" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#adafruit</a> HUSB238 module is a really easy way to accomplish this: simply (solder) bridge the pads to get the wanted output and it’ll magically be available for you at the output terminals 🤩 Further controlling is available through I2C and <a href="https://techhub.social/tags/adafruit" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#adafruit</a> has <a href="https://techhub.social/tags/circuitpython" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#circuitpython</a> and <a href="https://techhub.social/tags/arduino" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#arduino</a> libraries available - perfect! 👍🏼 This little PCB is (claimed) rated for 5A - I don’t plan to run it above 3A - the PCB traces look a bit small for even that but we’ll see how it goes ☺️<a href="https://techhub.social/tags/electronics" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#electronics</a> <a href="https://techhub.social/tags/electronicsengineering" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#electronicsengineering</a> <a href="https://techhub.social/tags/testandmeasurement" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#testandmeasurement</a> <a href="https://techhub.social/tags/rfengineer" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#rfengineer</a> <a href="https://techhub.social/tags/hamradio" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#hamradio</a> <a href="https://techhub.social/tags/hamr" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#hamr</a>

Søren KjærsgaardPreparing a little curve tracer demo, walking my way through some different diodes 🙂Starting from the left, an OA95 germanium, 1N4148, 1N4007, LEDs, a vintage 60V Selenium and finally, a zener.<a href="https://techhub.social/tags/electronics" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#electronics</a> <a href="https://techhub.social/tags/testgeartuesday" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#testgeartuesday</a> <a href="https://techhub.social/tags/rohdeschwarz" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#rohdeschwarz</a> <a href="https://techhub.social/tags/electronicsengineering" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#electronicsengineering</a> <a href="https://techhub.social/tags/testandmeasurement" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#testandmeasurement</a> <a href="https://techhub.social/tags/hamradio" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#hamradio</a> <a href="https://techhub.social/tags/hamr" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#hamr</a>

Søren KjærsgaardBuilding a Curve Tracer front end to the oscilloscope is really easy and allows you to measure diodes and other two-legged components I/V performance. Ever wondered what that mystery diode is? Here’s the way to find out 👌🏻🙂The one shown here is based on a ‘Popular Electronics’ article and it features a current limiter as well, but simpler circuits are astoundingly easy to build, just do a search for ‘Curve Tracer Schematics’. Hint for young players: the oscilloscope is used in XY-mode, in which, the time base controls have no effect at all - that is - on a good old analogue scope. Digital scopes however, are sampled devices and all they really do is mimicking analogue oscilloscope behavior, including XY mode, and this is why time base has an effect. <a href="https://techhub.social/tags/electronics" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#electronics</a> <a href="https://techhub.social/tags/testandmeasurement" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#testandmeasurement</a> <a href="https://techhub.social/tags/hamradio" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#hamradio</a> <a href="https://techhub.social/tags/hamr" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#hamr</a> <a href="https://techhub.social/tags/electronicsengineering" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#electronicsengineering</a> <a href="https://techhub.social/tags/electronicsengineer" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#electronicsengineer</a>

Søren KjærsgaardIt’s been 5 years since I started feeding <a href="https://techhub.social/tags/flightradar24" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#flightradar24</a> with a <a href="https://techhub.social/tags/raspberrypi" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#raspberrypi</a> and, initially, a DVB-T USB dongle. I quickly moved to the <a href="https://techhub.social/tags/flightaware" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#flightaware</a> Pro Stick Plus receiver and a much enhanced antenna, which gave me a significant range and performance improvement. Except…:I seem to be burning through a receiver about every year.. 🤷🏼‍♂️ They do run quite hot, seen here at 21C ambient, some components peak at 50C and that’s without the cover… I’m considering building a small enclosure with a fan to keep it ventilated without the plastic cover, any suggestions would be appreciated 🙂<a href="https://techhub.social/tags/flightradar24" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#flightradar24</a> <a href="https://techhub.social/tags/flightradar24feeder" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#flightradar24feeder</a> <a href="https://techhub.social/tags/flightaware" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#flightaware</a> <a href="https://techhub.social/tags/aviationlovers" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#aviationlovers</a> <a href="https://techhub.social/tags/aviationgeek" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#aviationgeek</a> <a href="https://techhub.social/tags/rfengineer" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#rfengineer</a> <a href="https://techhub.social/tags/electronicsengineering" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#electronicsengineering</a> <a href="https://techhub.social/tags/hamr" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#hamr</a> <a href="https://techhub.social/tags/hamradio" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#hamradio</a>

Søren KjærsgaardMy first time ever playing with tunnel diodes, believe it or not 🤷🏼‍♂️😂They start conducting immediately, but not much, then suddenly crossing some current level, they switch on super-fast, this one is measured in nanoseconds! Decreasing the current they’ll eventually switch off again, equally fast, delivering a Schmitt-Trigger response. They’re sensitive devices, you can damage them by using a diode tester on the multimeter, so be careful. They’re also ESD sensitive, so make sure to use a grounding wristband 🙂<a href="https://techhub.social/tags/electronics" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#electronics</a> <a href="https://techhub.social/tags/testandmeasurement" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#testandmeasurement</a> <a href="https://techhub.social/tags/electronicsengineering" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#electronicsengineering</a> <a href="https://techhub.social/tags/rfengineer" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#rfengineer</a> <a href="https://techhub.social/tags/hamradio" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#hamradio</a> <a href="https://techhub.social/tags/hamr" class="mention hashtag" rel="nofollow noopener noreferrer" target="_blank">#hamr</a>

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