What's in the box Mike? A pulse generator for NB noise blanker adjustments. Schematic and demo. 

Thanks for pointing that out. I completely missed that. I added a update to the description under the video.

@@mikesradiorepair - Good; inexperienced people might build the circuit and not catch that, wondering why it didn't work. But then that's how we learn! I've actually seen a board run a bit then randomly quit, then found it was due to the power pin on the CMOS microprocessor being bent under and not being connected. The CPU was so low power it could steal enough current from other pins to work up to the point where too many pins went low and it conked out. I've also seen someone put a PL-259 on RG-58 coax without using the UG-175 adapter. They unbraided the shield, soldered it into the center pin of the PL-259, and soldered the center conductor to the shell. I wished I could have taken a picture of it, I saw it and I could hardly believe someone could actually wire a coax connector backwards!?!

LOL, now that would be something to see. I have seen a lot but I have never seen a coax connector wired backwards.

Thanks for posting this comment. I just finished building MIke's Noise Blanker generator and found this out as well.

@@TheBrforsberg Glad to have helped; thanks go to Mike for the original design!

My NB tester was built eons ago with a 555 chip; I like yours and gonna make one just to say I've got a "Mike NB Tester"! ;-)

AllTheGearNoIdea hey what’s dead bug style? It’s a cool phrase! No idea what it means heh

KC1ANR Boston USA John Sorry for not replying I did not see your comments. Dead bug is when you build you circuit on a copper clad board but all the components have the legs sticking up in the air. ICs look like a dead bug when upside down

I'd need to look at how it's wired (don't have time right now) but if the outputs of all three should always be the same state and since this is a CMOS device I think it should be fine. I've seen two TTL gate outputs tied together as what's called a wired-OR or a wired-AND gate, too.

One could whip out a PCB in less than an hour and have a Chinese PCB maker make them for less than a $ each. Mike might be able to start a second business.

That's not what we're after here. If you look at his scope output there are still both positive and negative pulses. This setup just allows for a very short duration pulse, with about a 1ns rise time. You get both positive and negative pulses. The output pulses occur on the rising and falling edges of the NAND gate outputs. You could get something similar using a tiny capacitor (1pF or so) terminated into a resistor which would only allow the high frequency content of the fast rising edge to get through. The square wave output of the gates is rather slow, but the edges have very high frequency harmonic content, and that's all we want here. Honestly, the diode seems to be working more as a tiny capacitor in series with the cap before it to provide the HPF effect to get the pulse content.

@@defaultuser000 In other words, there's no need for a diode. The cap could just be changed to a few picofarads.

@@misterhat5823 Yes, you can replace the series cap/diode combination with a 1pF capacitor feeding the 100k output pot and you get the same type of pulse train at the output. It's just an RC high-pass filter you're making with the cap and output potentiometer. It's filtering out all of the lower frequency content of the square wave and leaving only the high frequency content of the rising and falling edges. It works great for testing noise blankers as Mike demonstrates. It's so simple it's genius.

Cobra sold numerous different base stations over the decades. Some of the more popular ones were the 89XLR, 139XLR, 142GTL, 1000GTL, 2000GTL. Where can you find one, anywhere used electronics are sold. Public auctions, online auctions, pawn shops, thrift stores, yard sales, HAMFEST shows/swap meets, etc.

He was getting TICKLING done to his toes