Apollo Comms Part 18: Solving the mystery of NASA's Updata Link box missing parts

We fix our Updata Link Test box by solving the mystery of the missing analog components. We X-ray mysterious Motorola modules, fight with misbehaving LC circuits, and help 1960's circuits with a dose of 1970's technology.

Ken's blog article about the X-ray reverse engineering of the Motorola modules:

Eric's new book, see first chapter:
Order on Amazon:

Links to doc:

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00:00 Recap of previous work on the UDL
03:53 The PSK circuit is has some mystery modules, and missing others
07:45 X-raying the mystery modules
11:43 Figuring out the missing circuit
12:29 Experimenting with misbehaving inductors
17:58 We find the right coil to build our missing filters
19:27 Generating PSK with the new filters
20:27 Adding the missing oscillator
23:14 Final test

[mpbgp]

When CuriousMarc posts a video it is a drop everything moment.

[luke]

I was on a team that helped manufacturer microwave resonance cavities and other ceramic/glass to metal components used in the Iridium satellite phone system. I touched something that's in space. I was like five subcontracts removed from the final product but I had a lot of fun. That's the coolest thing I ever did. I was a grunt in the process but thrilled to come to work everyday. These guys just do it for fun. NASA gear everywhere.... In his house🤯 I'm a spectator here for the most part. Massive analog electronic fan. Modest knowledge of electronics. I can barely fallow most of it but I love watching these guys do their magic. The big iron stuff tickles my brain. I absolutely envy their level of knowledge.

[AnalogueGround]

What an incredible team. Reverse engineering Apollo comms gear is not for the faint hearted but if you put the practicalities aside, it's the passion and dedication that shines through. In a screwed up world here is a safe haven where we can witness human potential at its finest. A mere thank you is not enough.

[MrMilarepa]

What I love about these videos is that you can watch them many many times and every time you understand a little more.

[tedvanmatje]

On the short list of people who should be made immortal, I think Ken should be one of them. The amount of knowledge he has in his head should be a legend! 🖖😎

[roadcrewworker]

The bar has been raised and now i will no longer accept any signal processing explanations without dogs.

[discowt]

An early Sunday morning, ready for breakfast.
Oh wait, hold my coffee. CuriousMarc has posted a new video.
25 minutes later... coffee is cold

[alpcns]

Each and every episode is a true pleasure. These guys are geniuses.

[TheHighlander]

I'm slowly shaking my head in disbelief...because I have no words for how amazing I think this is. Well done. Just mind boggling..

[matthewfarr]

Your videos are a master class in thinking and applying knowledge. I wish this sort of collaborative thinking and work could have been part of my electrical engineering curriculum way back when. We NEVER played with analog electronics like you do, it was always very cut and dry in the lab.

[DocBanner]

"Stay tuned" for the next episode at very end. Nice one

[Spookieham]

Thanks! A tiny payment to help one of the best YouTube channels going

[douro]

You will sometimes find PCB mount tuning fork resonators which were made by Murata and Fuji Electric in Japan. They were made to be used in tone control circuits and they are sometimes found in answering machine remote controls. They have piezoelectric transducers for the output and the drive input. Driving them requires only a simple single-transistor circuit.

[malcolmgibson]

Greetings earthlings means that a very interesting video has arrived but this one is one of the best. I love Ken's re-engineering of circuits.

[PINKBOY]

Do remember that Nasa used another fork oscillator on spacecraft. Not for electronics, but for time keeping! The Bulova Accutron!

[LMacNeill]

Ken's reverse-engineering skills continue to amaze me. And that self-contained X-Ray machine -- what a great piece of kit that is!

[joswhite]

It is great to see the difference between "the book" and real life beautifully demonstrated. These videos beat the lecture hall any time.

[djmips]

You sure do meet some really cool people Marc! Thanks for the Open Circuits book tip. I pre-ordered the hardcover!

[bennock]

I thought I knew a lot about electronics, watching Marc and his team I realise now I know very little. Great series.

[cphrpunk]

Needed some inspiration, thanks for the post. Staring at a breadboard and a pile of components.