A Crummy Commercial

At GTE I used to work on Fairchild Sentry IC testers like this Sentry 21: The test head of the Sentry had pin electronics cards arrayed around a circle: source:  https://caeonline.com/buy/final-test/schlumberger-fairchild-sentry-21/9267919 Here is an interesting paper on testing the Z-80 with a Sentry 610: substack:  https://mtsi.substack.com/p/testing-the-z80-chip-with-a-1970s   article repeated here:  https://mitsi.com/case-studies/z80-chip/ One thing that were used on the pin electronics cards were small reed relays, either Zestrons: source:  https://www.ebay.com/itm/296449132308 or Coto relays: source:  https://www.ebay.com/itm/394476842759 The reed relays were also used on "performance boards" which were the interface between the test head and the device under test - the relays were usually used for applying loads or power to a pin.   One thing with the reed relays, they weren't soldered onto the boards, we used small pin sockets like these: ...

I was thinking about taking a bicycle ride when I started hearing periodic booming about 8 AM.  I finally realized it was thunder even though it's a sunny day here. The radar GIF: It's amazing to me that the sound of thunder (strong enough to rattle things) is able to travel about 30 miles (48 kilometers) !  Poor Escanaba, about the only city on the map being hit by a storm. This reminds me of the recent post on the lightning video: https://wb9kzy.blogspot.com/2025/09/martha-get-buckets-tree-by-lake-is-on.html  It also reminds me of this poster from the 20th century: I've got one of these around here somewhere source: https://www.ebay.com/itm/226934099585  I need to get some kind of lightning detector going, can't always rely on 70 year old ears.   Best Regards, Chuck, WB9KZY http://wb9kzy.com/ham.htm 

Blogged on wanting a new camera stand for bench photos yesterday: https://wb9kzy.blogspot.com/2025/09/this-isnt-true-need-maybe-more-like-wish.html  I found this: pictured with the folded up Kalimar tripod mentioned yesterday on the right. I'll give the Vivitar a try, if it's NG I'll keep looking. BTW, I remember when my Mom and her friend from Pewaukee went on a trip to Japan.  The husband of the Pewaukee lady wanted her to buy some camera accessory from Vivitar.  It turned out that Vivitar was (is ?) a US only brand, trademark of the Ponder and Best company.  So his wife wasn't able to get that camera accessory.  I also remember that trip with a little regret, mainly that I had asked my Mom to buy a camera - and she felt she had to carry it around with her - SLRs were heavy then.  Now of course I never use that camera - I wish I had asked her to get me some good quality mini-binoculars - those would always have been useful and much easier for her to carry...

I'd like to have a portable copy stand for taking pictures on the bench.  Something small, light and easily adjustable (unlike what I currently use: a Kalimar mini tripod which I think I got from Porter's Camera When I was into photography I would see items like this in camera magazines: a lot of the camera companies sold something similar for their cameras source:  https://www.ebay.com/itm/146655304646   But I never bought one - and while the prices on Ebay are actually very resonable considering  it's a Leica product, they are meant for a Leica film camera and not for a modern digital camera, smartphone or tablet. I actually do have a copy stand, it's my old enlarger with a threaded rod accessory to replace the enlarger head.  But while it's nice and rigid it's too heavy and bulky.  It is very similar to this: this doesn't include the post, mount and base source:  https://www.ebay.com/itm/297581762098 Maybe something like this: source:  https://...

Three unusual things I noticed on Saturday.  First: I got an email from a "person" who was interested in this: This was the ema il: The email seems off, written by a machine ?  Or possibly  a machine translation ?  I can't remember ever using the word: semantics in an email subject line. Two other things: there is a mistake on the 6 bit D/A => no path for current to ground or VCC.  A resistor to ground would work.  I removed the 6 bit D/A schematic from the zip on the projects page. I foolishly replied to the email with this so maybe I have been marked as a sucker ? Another thing: the schematic was on a scraped data page found with this search:  "Fm Radio Circuit Diagram Pdf"   But a few hours after my email reply that 25 year old 6 bit D/A circuit diagram had disappeared ! Very weird, so possibly this email was from the goomer who runs that site or they just rotate their filched content regularly ?   I never heard back from...

After the recent loss of the 4 LED bulbs to lightning: https://wb9kzy.blogspot.com/2025/08/lightning-strikes.html  I replaced them with 4 bulbs stolen from other fixtures inside the house.  So I went on Ebay looking for replacement LED bulbs and found these: The idea is that instead of the snow-cone style (where the LEDs sit on an aluminum circuit board) of LED bulbs like the ones that were damaged, I thought that these newer style bulbs with the two long "filament" style of LEDs would be perfect for the bath: The problem with snow-cone bulbs is that they are more like a spotlight, the light shines in a smaller than 180 degree arc.  With the filament style bulbs the light has a much wider arc.  This is perfect for bath vanity style fixtures: where a set of bare bulbs is able to shine down (and up) as well as straight ahead.  This makes them more useful since there is a higher light level when leaning into the mirror to see something up close. These particular bu...

Everybody remembers this: source:  https://www.youtube.com/watch?v=anWLvZdn368 I lashed up my Sony muter plus delay for last nights Packer game: Jayden and Jordan after the game old Sony TV remote, Sony stereo remote, muter, 9 volt power supply The delay itself was supposed to be 2 minutes but it came out as 2 minutes and 2 seconds.  It actually worked pretty well even for football which is a little less time regimented than modern baseball - George Carlin must be spinning in his grave ! source: https://www.youtube.com/watch?v=zeCtFkHQtEo  The muter was connected on one leg of the left speaker.  The right speaker was disconnected.  One question: does it harm an audio amp to be run without a load ?  Certainly that is true with an RF amp but an RF transmitter is generally run at high power.  Most casual listening to an audio amp is done at milliwatts.  So the output stage should be able to dissipate the power.  But it's prudent to run the ampli...