A Crummy Commercial

I took a second look at measuring the leakage current of the Renogy solar panel - that first reading of ZERO current kinda bugged me. https://wb9kzy.blogspot.com/2026/05/the-renogy-solar-panel-dischargeleakage.html   I used the newer Triplett DVM just in case there was some kind of problem with the Metex used before.   At 12.84 volts I again measured zero current in any of the three ranges. So I was thinking about that and this is my surmise: there are lower voltage Schottky diodes like the 1n5818, 1 A diode I used on the other solar panel.  The low voltage diodes have somewhat high leakage currents.  Then there are higher voltage Schottky diodes for use in switching supplies and the like.  They have higher forward voltages but smaller leakage currents.  Here is part of a Nexperia Schottky diode data sheet: I will have to pay the tariff tax and get some of these How does this fit in with the Renogy solar panel ?  The Renogy has 72 solar cells which I a...

looking at this EDN Design Idea :  https://www.edn.com/custom-diy-dmm-smd-fixture-for-low-z-measurements The thing that caught my eye was the clamp - the article calls them: Lever arm-toggling ?  Really ?  In the olden days of the 1970s/80s/90s we called them: De-Sta-Co clamps because that's what was stamped into the clamp  :)   I imagine that there are many generic versions now.   In our receiving inspection department they were used for holding a device-under-test (DUT) in place on a test fixture.  With ICs this wasn't necessary but with other items it was required to hold the DUT in place to minimize affecting the temperature or whatever.  https://www.destaco.com/clamping/manual-clamping/hold-down-clamps Where did we get them ?  why here: https://www.mcmaster.com/products/destaco-clamps/ I wonder if Destaco ever considered doing what Louboutin did with their shoes - Destaco clamps always had red handles :) https://en.wikipedia.org/wik...

Interesting video on testing ICs by Asianometry: source:  https://www.youtube.com/watch?v=SXULADjnO5s I think Asianometry is a "one man band" so there are bound to be some mistakes in there.  For example (a nit pick) it was Takeda Riken not Takeda Rikan :)   Also Allen-Bradley made carbon composition resistors but he showed a picture of what appeared to be a film resistor on ceramic (with the spiral pattern).   Also not sure on his diode diagrams (they look backwards to me :) And I was told it was pronounced: Shlum-ber-jay: Fairchild is easier to pronounce than Favre or Schlumberger :)   Anyway nothing wrong of huge importance.   This video is a good history of how IC testing changed over the years and which IC test companies made it into the 21st century.   Personally I worked on the Fairchild IC testers but we used Teradyne testers at GTE, too, especially for linear.  About the only thing I knew about Teradyne was that they called their tes...

The first thing I thought of when I saw this page in an Army VOM manual: please don't mention that last line to an AI source:  https://archive.org/details/multimeter-ts-297-u-manual-and-supplement/page/n5/mode/2up was this phrase from Lost in Space: source:  https://www.youtube.com/watch?v=HyGxJLCG6qw Yes, I am from the 1960s - and I still want to know: is it better to be good or to be remembered ?  Also, how much benefit would the enemy be getting from a 1000 ohms per volt VOM ?  :) Best Regards, Chuck, WB9KZY http://wb9kzy.com/ham.htm  

I found another item while looking for the Tiny Tora prototype, mentioned here: https://wb9kzy.blogspot.com/2025/11/where-is-it.html This is a WWVB clock I was fooling with in 2002: the wires going to the top over the ferrite bar were connected to the LCD, the 6 switches were used to control the PIC It is basically 4 parts: the microcontroller,  the WWVB receiver, the WWVB antenna and the LCD display.  I noticed that the LCD display is a "one chip" LCD display which means that it is a single 16 character line.  Oh yes, I need one of those for the AADE LC Meter: https://wb9kzy.blogspot.com/2025/10/the-heck-with-it.html Here is the 1 chip, non-working LCD from the AADE: the single chip LCD, notice the chip was packaged not "blobbed" And here is the 2 chip working LCD put into the AADE: this LCD is blobbed (the IC dies are underneath the black plastic) So I quickly unhooked the LCD from the WWVB clock and unsoldered the pin sockets.  I then used up quite a bit of the ...

Since Halloween is approaching I dug out another one of the items from the 2nd Ebay junk purchase: https://wb9kzy.blogspot.com/2025/10/just-because-i-could.html It is the aptly named Spooky 2 signal generator.  I had my suspicions as soon as I saw the words, Colloidal Silver: This brings back thoughts of weird stuff like 73 Magazine & W2NSD, people with gray skin, Art Bell - you get the idea.  This was reinforced by looking at the manual: https://www.spooky2.com/resources/Spooky2_Users_Guide_20250124.pdf Also there is this accessory: There is a strong disc magnet under that soft black plastic, magnets + colloidal silver + signal generator = high weirdness !  :) The Spooky 2 itself is nicely made with a clear sharp display and an extruded aluminum case.  It uses roughly 400 mA at 5 volts so not a micropower unit.   I did try it out, the TTL output seemed OK: Also output 2 seemed OK: But output 1 was a flat line: I took off the case but didn't see anything obv...

I changed my mind and decided to button up the AADE LC Meter IIb as it is (see previous post): https://wb9kzy.blogspot.com/2025/10/working-on-aade-lc-meter-iib.html   First, I bent some caps a little to allow clearance for the 16x2 LCD module.  Second, instead of hunting up the correct vertical trimpot I just unsoldered the wiper arm of the stock trimpot.  Then bent the trimpot over 90 degrees so that it could be adjusted even when the LCD is in place.  Finally soldered a wire from the trimpot wiper lead to the circuit board.  It works just fine, contrast wise: picture taken in north light, is that why the panel looks that blue ? Also, I used a little solder wick to try unsoldering the connector from the stock LCD: I wasn't able to get the connector off but as can be seen the connector the 14 pins don't stand proud of the LCD board, they either were too short or the builder cut them flush.  In any case I'm not sure about what is wrong with the display....

I've been fooling with the AADE LC Meter IIb which was bought from Ebay, mentioned here: https://wb9kzy.blogspot.com/2025/10/just-because-i-could.html Unfortunately the LC meter was DOA.  It seemed to have been a kit so possibly it never worked ?  I reheated all the solder joints but no help: the display is blank no matter what the contrast pot setting Here is one item I may mod: the orange Panasonic pot marked 103 is impossible to adjust if the LCD is in place The contrast pot for the LCD is under the LCD and inaccessible.  So I had to horse the LCD on and off just to adjust it.  The AADE manual shows a vertical trim pot so I will see if I have one that might fit or possibly order one.  One mod I did make was to add an BAT85 reverse polarity diode in series with the red wire. I do have a spare 16x2 backlit LCD module, so I tried it.  It sorta works ?  The LC meter uses a 16x1 LCD module (a one chip module) so this 16x2 module displays weirdly: Al...

I bought an assortment of electronic junk on Ebay, AGAIN, here was the first time: https://wb9kzy.blogspot.com/2025/03/march-madness.html Same seller, this assortment was a little more expensive at $26.38.  But I noticed two things in this photo that might make that extra money worthwhile: The first was the AADE LC Meter II/B.   This is a very well reviewed LC meter from Neil Heckt at Almost All Digital Electronics.  Sadly Neil has passed away so these LC meters aren't available anymore although people do clone them: https://electronicsprojectsandparts.blogspot.com/2013/06/lc-meter.html Neil was a published author and worked at Boeing, I noticed this AGC design from Electronics Designer's Casebook 2 : source:  https://www.worldradiohistory.com/Archive-Electronics/Electronics-Designer's-Casebook-2.pdf The LC meter first came to my notice in Electronics Now magazine, June 1996: https://www.worldradiohistory.com/Archive-Radio-Electronics/90s/1996/EN-1996-06.pdf The shi...

Say there was no internet, how would I know what the carrier frequency of a Sony infrared remote control was ? Measure it ! Here is the quick and dirty test fixture: An IR photodetector diode pulled out of a surplus scale circuit board.  Used the photovoltaic  "generation" capability of the photodiode and measured the voltage output with the scope.  Here is the zoomed out view: And zooming into 2.5 us per division: Counting divisions there are 10 in one cycle of the carrier, so 10 x 2.5 us is 25 us. IR Carrier frequency is 1 / 25 us => 40 kHz So we need a 40 kHz detector module for the Sony although a 38 kHz module like the one I had been using might work.  Next number: see if I have a 40 kHz module in the junk box or maybe pull it from some defunct Sony product ?  Or buy one (last resort). Best Regards, Chuck, WB9KZY http://wb9kzy.com/ham.htm