Videos by Roger Leifert from the KainkaLabs Vault. This is the official channel from AK Modul-Bus aka "kainkalabs" from Germany Dedicated to Open-Source Hardware and the Maker-Community. Owned by Burkhard Kainka (hence the name) who is a well-known electronics-autthor and kit-maker in Germany.
I recently bought some JFETs from AliExpress. The BF245Bs were fake: NPN BJTs as per your video. The BF245As gave very peculiar readings on a component tester similar to the one you used. Vb was 385mV and Hfe was 184K and it showed up as a NPN BJT. I was able to repeat these tests with a Peak Electronics DCA75 component tester. The BF245s tested as NPN transistors as before but at a collector current of 5mA, Hfe was 278 and not over 400 as before. I think they are 2N3904 or similar. The BF245As, however, tested as n-channel JFETs, as they should. The pinch-off voltages were around 0.5v or slightly less. Perhaps the cheap testers cannot test JFETs with low pinch-off voltages.
I like it. The only thing I'd do differently, is add a 9V tap and add one tap that runs through an LM317 with a potentiometer for adjustment. In fact, that's what I did when I built a very similar board for my own lab. That said, this board is much "cleaner" and neater than mine, and I might just buy one or two of these to have around. 🙂
One downside to the silicone mats I’ve found is that they carry a very heavy static charge. I have an L shaped glass desk that got bought some silicone mats for and they have such a great static charge that I’m afraid to use them on the desk because that’s where my computers will be. Trying to figure out a good way to either ground them to the metal frame of the desk ,of discharge the static into/onto something else but still looking into how I can do it. Any suggestions?
Hi Mr. Very good video! I found the same issues with mine that I bought assembled. I was in doubt if it was defective or a design error. You solved the doubts. Thanks! Just one issue: I've tried to download your schematics with optimized components and instructions but received a "The request is blocked" message. Could you please help me with this issue?
Link has been changed to the kit in our online-shop where you can also find the documentation. Should work now. Built-manual is only in German until now.
Just bought the Super fx 991D and waiting for it to ship. It’s nice and thin, which is perfect, but the persistent engineering mode is amazing for circuit analysis. It’s not a 61f, but it’s also 15-20x less, so more than worth it.
It is all about minimising self capacitance. This maximises the tuning range. The coil that looks like a star is the right way to do with this - keep the turns far from each other.
Yes, but much more difficult to wind. The "spider web coils" have low enough self capacitance for tuning the whole AM-range with a 500 pF variable capacitor. More important than the self-capacitance is the lower (external) proximity effect of the star-like coil!
Hello, Thanks for all your incredible work on this fix. For some reason I can't access the link in description for fix. Do you have an alternate link I could download instructions for fix please?
Link has been changed to the kit in our online-shop where you can also find the documentation. Should work now. Built-manual is only in German until now.
WHERE do and WHY do they use silver? What argument do you have against my reasoning and experience and even the demonstration showing an old silver-wire which is clearly sulfurized and thus has more resistance in RF-applications compared to enameled or PU-coated copper-wire?
Ah. OK. So, I didn´t know for what purpose and for what reason silver is used in rockets or in cruise-missiles like Tomahawk. Do you have a link where I can find that? Then I can tell you if they make/made the same "mistake" as those who use silver wire (or silver-clad wire) in electronics for the initial slightly lower resistance than copper or if it is a completely different reason.
Flatcable is typicaly 0.08mm^2 and the knipex 12 62 180 is designed for 0.2 to 6mm^2, so you cannot complain that it doesn't perform well enough for something that it wasn't designed for! From the video I am guessing that you are right handed ... might sound silly but use your right hand for the tool. I have the mulstrip 10 and it performs as expected (I mainly use for thin electronics cables)
Thank-you!!!! When I first began learning electronics I came across a super simple circuit of two LED's in parallel but flipped in opposite directions. It called for applying an AC Sinewave which would alternate the flashing of each LED. My oscilloscope had a function generator BUT the sinewave's voltage output was so low it couldn't power on an LED. So I bought this same cheapo XR2206 but was once again disappointed in that it would only light one LED solid but the other LED stayed off. As per your suggestion, I added a 100uF Capacitor to the output AND NOW both LED's flash as expected and I can even adjust the frequency!! Can someone explain why adding the 100uF capacitor solved my issue??
In academic theory you are correct. In "real life" most people (including me) knwo what I mean and in HiFi-amplifiers this term is used forever and everybody understands what is meant.
The link is kinda "brokenISH" at least my antivirus (ESET Internet Security) is blocking it due to an issue with the ssl certificate, like it is not trustable or something or it is revoked...
Link has been changed to the kit in our online-shop where you can also find the documentation. Should work now. Built-manual is only in German until now.
Thank you very much for this video! I am from India, a Bio-Medical Engineer by profession & a radio & vintage audio & tape recorder hobbyist. I want to know the reconditioning process for the compact film type ganged capacitors. Please let me know through your video in case you have done any work particularly on these components. Regards!
What do you mean by "ganged capacitors". Like the metal one which is shown in the video? Use compressed air for the metal plates. If the axle is stuck, soak it in acetone or another organic solvent and relubricate it with modern "non-ageing" grease.
I'd sure like to read Roger's customer Review on this Impossible disaster !! .....How possibly can this "machine" work with non-conductive "Painted" segments ?? ....Maybe it's really a Bonetti "Sectorless" Machine !!
It’s been a while since KL released a video. Hope all is well. Yours is one of the best ECE channels around. I have a bunch of questions about the ks7000. Let me know if you wouldn’t mind answering a few. Thanks for all the great videos!!
This is where you find most products from this video-series: www.ak-modul-bus.de/stat/laborzubehoer.html (Delivery worldwide to all English-speaking countries, but expensive outside of Europe)
As incredibly Impossible for this Poorly designed screwed up Chinesium Wimshurst machine to Work, it somehow manages to Produce some sparks & actually Shock the irate Presenter !!!
Yep HP-35S is GREAT! ...But INSANELY priced, when HP still sold them. Now used still crazy price! :( The newer CASIO Fx-981EX on the other hand is GRAT VALUE! ...even though they F...ED up the u m k etc. is now a three button sequence , ....MORONS!!!!!!!!!!!! :(
You can't measure RMS power with anything because there is no such thing. You only have RMS values for voltage and current; the product of these is average power.
@@KainkaLabs My point was that there is no such thing as RMS power. It is only average power. The complex load situation means that you need to multiply by the COS of the phase angle to get power. That is always true.
So you take a (very) complex load like a loudspeaker and feed a pink noise signal into it. What happens with your argumentation/definiton? There is no cos(phi) in that situation to work with. The measurement device that I show in the video does accurately measure the RMS power (or if you like real power or true power) in that situation, because -as you will know- the RMS-value is the equivalent value that develops the same amount of heat in a resistor. You say "there is only average power". Which kins of "power" do you mean to be averaged in that definition? Active, reactive, apparent or complex power??? So your definition is incomplete, while the definition of any RMS-value is always related to how much heat is developed in a resistor. So the definition of RMS-power is unambigous, while "average power" can be interpreted in many ways (see above). Every practical working person (except perhaps university teachers for theortivcal physics or theoretical electrical engineering in their ivy towers) knows what is meant by and how to interpret "RMS power". en.wikipedia.org/wiki/AC_power#Apparent_power
6 years later and this is still incredibly helpful! Thank you so much for the time and effort you put into this. Tracking down components for the upgrade now!
Link has been changed to the kit in our online-shop where you can also find the documentation. Should work now. Built-manual is only in German until now.
Link has been changed to the kit in our online-shop where you can also find the documentation. Should work now. Built-manual is only in German until now.
No, because the componetn tester cannot differentiate between Germanium ans Schottky diodes. They have the same forward characteristic, but usually the reverse current is not measured. And the reverse current makes the difference.
That´s basic electronics: Put a constant voltage at an inductor and current rises linearly (until either ohmic resistance or saturation of the ferrite material sets in)
read carefully what I wrote, also that in the brackets. Look up your textbook or wikipedia about inductors and capacitors. Capacitors are the inverse elements to inductors. Exchange I and V and you understand the other part. With a capacitor, charge it with a constant current and you get a linearly rising voltage --> with an inductor, put a constant voltage to it´and you get a linearly rising current (until........... see above)! Case closed.
@@KainkaLabs We are both correct in a sense. The current in an ideal inductor in isolation will rise linearly when charged with a constant voltage. However, ideal inductors don't actually exist. In that case there is always some resistance, and when resistance is present, the current in the inductor will rise exponentially as per the formula I provided. I hope we can agree on that.
Yes, it is basic electronics. I recommend Michel van Biezen's video "Electrical Engineering: Ch 7: Inductors (7 of 24) DC Current Through an Inductor" where he explains the exponential behavior of current through an inductor with constant voltage and takes into consideration the resistance with time constant L/R. Seems like you were unaware of that.
The basic question about any spray or fluid is whether it takes any contaminants with it when it vaporizes. Mostly not. Just think why distillation works for separating for example alcohol and water. In the cleaning attempt, the original dirt rarely evaporates along with the solvent. Your test with the paper also shows, even without original dirt spot, how something was left as a ring. I would really favor washing - ultrasonic or whatever - than depend on vaporizing. If I have to depend on the spray cleaners, I would apply so much, that the cleaner and dirt can be shaken away together, rather than hope that the dirt miraculously evaporates as well.
The spray and fluids shall wash away the contaminats, not "evaporate them", which is of course nonsense. Ultrasonic cleaning has it´s own dangers. It can destroy parts by vibration. And you have to desolder the part first of all and then take it out to get it into the US-cleaner. And you have to have at least a semiprofessional US-cleaner. So strays and fluids are in most cases the thing to go with first.
You will only in very rare circumstances find a replacement potentiometer that fits mechanically, has the same value and charateristic and the same quality. Look e..e. at the potentiometer at the bottom right. Where do want to search for this one and what are the chances you find the exact type?
In my unit, the up and down buttons do the same thing. It cycles through the main menu or any sub menu list in the same direction whether you press up or down.
