Beautiful stuff. I worked at Motorola GEG (Gov't Electronics Group) in the late 1980s and many of my older colleagues had been involved in development of these radios.
The ADC restoration was the best 30 hours I've ever spent on a RU-vid playlist. Fangirls like me have a high bar for this series, but only because you are the best person possible to document this.
Fellow fangirl reporting in... Have been hanging on for this series since it was teased ;) I have always admired the attention to detail and care taken by Marc & co. with previous projects.
This is absolutely a marvel to look at. And to think that the required math needed behind these things were done by slide rule calculators. And to think these primitive systems brought us to the moon and back. They don’t make things like this anymore. Stuff nowadays is designed to be disposable.
This is so fantastic. It makes such strange phenomena as moon landing deniers even more perplexing, when all the engineering artefacts, designs and administrative paper trails are so detailed and complete. Faking all this as well as the landing would have been more work! Thanks Marc.
Lack of knowledge gives rise to mythology and conspiracy theories because the ignorant are easily misled. When your knowledge of microwaves is limited to making popcorn, faking the moon landings sounds reasonable.
"5G is microwaves, and microwaves cook things, therefore 5G cooks people!" - Conspiracy theorists in a nutshell. I work with radio waves as a hobby, and I know for a fact that RF radiation is completely safe, unless you're right next to a very powerful transmitter for some reason. That is why there are warning signs on radio towers, because engineers know that radio waves CAN be harmful under specific circumstances (I.E. being right next to a several-kilowatt transmitter), and have implemented measures to protect you with fences and signs. That is, unless you're a moron who decides to destroy cell towers for no reason, in which case many people may get hurt.
I've only met 2 in my entire life, I. Really think their numbers are way overestimated so people like us can say, "at least we're not stupid clowns like those people."
@@vincei4252 Wise words and yet I think the psychological phenomenon is instructive, especially to people who consider themselves well-educated and rational.
They built the amplifier here in town (Cedar Rapids). Probably some retirees that designed it still around. Posted link on fb. I think they will enjoy the series.
Gorgeous, brilliant and fantastic engineering. Absolutely stunning, just spectacular what you guys routinely do. Apollo still gives me goosebumps. It must feel like finding and opening the Ark of the Covenant or something similarly ultra-special. Thank you for these priceless videos and enormous efforts.
Marc, this reminds me of when I was a lot younger, I worked for a company who did a lot of work for the DOD and also for NASA. One of the contracts they had was for the L.E.M. (the lunar excursion module) trainer. I worked on the electrical hook up of all the gauges and lights inside. After all was completed, I sat down in the center couch and looked at all of the gauges lit up. Quite impressive. I never forgot seeing all of the EL panels.
You had coworkers who helped with the LLRV? Awesome! It’s amazing how many people have a link to this wonder of human ingenuity. Also, I assume you worked at Bell Aircraft (since they’re the ones who built the LLRV): If so, did you work at their helicopter division? I think hearing that one would send me to the moon WITHOUT a rocket, lol!
For transmitter comparison; I can get a 2.4Ghz 1 watt transceiver for an FPV drone for $30, that weighs less than 30 grams and is only 20mm X 20mm. How far we've come!
Well Ewen the frequency is sone or similar ... It'll not be that powerful.. if they manage to make this devices work and put that on a drone I'm sure their range will be more then 10s if kilometers in earth surface Ewen with relatively small antennas.
I'd be very curious to know how big this would be now if we had to build it with our current technology, with the same signals in & out. And also how much wattage the new box would be consuming...
I'm a radio technician and I'm fascinated by this, how the comms systems worked in the Apollo program. They were very clever engineers to develop the PLL and other systems and all done in the 1960s. State of the art for the time. A close look at the transponder module, I saw a VCO module and the other receiver modules, looks like a dual conversion receiver.
Good eyes! It is a dual conversion receiver. Everything is done with PLLs, including the PM and FM demodulators, this is much more advanced than I would have thought.
A correction to your narration: The old Collins Radio Company is now Collins Aerospace, a part of Raytheon Technologies. "Rockwell Collins" is no more.
I am amazed every day by modern technology but I have far greater admiration and respect for old tech like this because it required tremendous brain power and teamwork. Much of today's tech is developed using computers for design and simulation, whereas Apollo era tech was built by hand using blood, sweat, tears, cigarettes and coffee. They couldn't just build a com system that worked, they had to build a system with the highest reliability humanly possible. I would say that next to life support the com system was the most important part of the spacecraft.
@@uploadJ I realize NASA used IBM's, Sorry for the blanket statement.. The engineers and machinists used side rules for the most part , I still have my father's..
Always a joy to see Mike, even if it's brief. His enthusiasm and knowledge is simply astounding. The perfect guy to have by your side when prospecting for Apollo gold!
what a great piece of technolgy and history.. incredible this thing worked ;).. and none of the hand made systems with tubes, and soldered wires in the AGC and billion other strange components ever failed in the missions
It was like watching silent home movies from the 1960’s narrated by my uncle! You could have added a “vintage effect” to make it seem even more “60’s” ! Haha. I was waiting so long for your next episode. This did not disappoint! Thanks Marc!
Now this is my jam right now. (I'm a RF system eng. in my day job.) The modules on the transponder looks kind of like the modules from the Old Motorola star point Microwave systems.
It's amazing what they pulled off with such a small amount of power and tubes! It truly was a giant leap for Mankind. Thank you for sharing this with the world.
There is one, in Louisiana I think and one in Dayton Ohio near wpafb, and I think another in DC somewhere, but DC is a pain to get to. The Ohio one is pretty incredible, got a Saturn v on the lawn
@@CuriousMarc I feel I shouldn't really have needed to point it out=) I can't wait for the next episodes. Do you have a way to send and receive to emulate a ground station?
I had a quick read down the comments but couldn't see what I wanted to mention. You say they operated three links, for the CSM, LM and S-IVB stage. However, they would not usually power the LM during the trans-lunar stage since it shared the same carrier as the S-IVB booster. This allowed them to perform ranging on the booster stage until it impacted the moon, at which point they could power the LM without interference. However, during the flight of Apollo 13 they had to power down the CSM. At that point the carriers for the LM and S-IVB conflicted and they lost uplink. They were very lucky that the larger ground station was just coming on line and could physically discriminate between the two in terms of their position in the sky. By getting PLL with the one they could then manually steer the frequency away and allow the lock to be acquired with the LM again. I did not fully understand this until you described it so well. Listening to FIDO having a blue fit on the Apollo 13 loops is priceless. As is the calm response from SELECT. It's another piece of overlooked history that deserves to be remembered... thanks Marc. 😊
@@uploadJ I seem to be having trouble posting a reply to you. But I think we are talking at crossed purposes. The beacons on the lunar module and booster stages both transmitted on the same frequency. That's why there was communication failure, not because they had turned off the CSM beacon. If you Google the UniverseToday article that covers the Apollo 13 S-IVB frequency issue you will find more info. Also, if you go to Apollo In Real Time and choose the Apollo 13 loop for FIDO, scroll to mission time 058:33:00 to hear Bill Stoval or possibly Jay Greene realising just how much of an impact this is going to be. Keep listening for at least 5 or 10 minutes.
Engineering at it’s finest. I keep wondering how those equipments performance were measured in the past, like THD, Noise..without a frequency analyzers, vector analyzers and all the digital modern stuff. Nothing but amazing 👏🏻
They had those tools, they were already needed for radar development. The tools were also large and expensive. I used to have a Polarad spectrum analyzer the size of a large doghouse and weighing nearly 100 pounds. The microwave test equipment used a lot of Klystron tubes and microwave diode mixers and cavities. No transistors at all as these 1960 equipments could only rely on like 4Mc/s germanium transistors.
These are the most beautiful Apollo parts so far, at least in my opinion. The construction of the Transponder is surprsingly similar to some old HP testgear, which is pretty cool.
Microwave guy here....nerding out big time! I started out my tech career testing TWTs back in 1978 at Varian Associates in Georgetown Ontario. I was hoping to find out more about the NASA USB system at some point. Thank you for these two videos!
I just started this series. I now suspect I have several S-band transponder modules in a box in my basement. Can't wait to see more of this series to learn more.
Brilliant! I look forward to more in depth study of the technology of the Apollo space program. The race to the moon created the progenitor to all the technology we are so familiar with, including the device I'm using to watch and comment on this video.
Remember this is technology from the 60’s. THE 60’s!! Almost as jaw-dropping gorgeous as the AGC. Can’t wait for you magicians to test it transmitting original Apollo footage.
In parallel with this, man, i would love to see the tech behind the Lunokhods. I mean, considering it landed on November 17th, 1970 months after... you just have to wonder. I think the transmission number for TV images is pegged somewhere at 20k + other things like panoramas. But i bet getting your hands on the transmission modules is like trying to find gold in ether.
CuriousMarc already has demonstrated his respect for Russian technology in his Soyuz-clock videos. Would anyone like to ask Mr. Putin if he would be interested in sending a ground-test article and a set of schematics over to the lab?
@@jlwilliams I have a huge respect for Russian technology. They may have had often quite subpar materials and had to cut corners, but they DEFINITELY weren't incompetent, NOT AT ALL. Whatever you look at, they absolutely knew what they were doing and made stuff possible with basically junk components nobody would ever have believed to be possible here.
One clever device that Soviets developed then, and are still using in their spacecraft today is a gamma-ray altimeter. It shines a beam of gamma-rays down, and measures how much radiation is scattered back from the ground. The beauty of this is that the reflection happens from the dense material only, and the signal is not significantly affected by the dust, snow, grass, etc -- the stuff that you should ignore when landing. Soviet moon probes and Soyuz landing capsule all use such altimeters.
Me and Ken were thinking the exact same thing - it would be interesting to see how the Russians did it. Putting a remote controlled rover on the Moon in the 1960's is no small feat.
There is an interesting fact about the Parkes antenna (04:50) as in the moment of Armstrong's first walk on the Moon it was the last one who had contact with Apollo 11 and as thw Moon was very low on the horizon the dish was kept at its lowest declination nearly toucing the ground and in that exact time the wind rised first at 50 kn and then at 100 kn, at windspeeds higheer than 30kn in order to preserve the instrument the dish should be pointed at the zenith, but the tecnicians of Parkes bravely decided to keep it pointed towards Apollo 11 risking their onw life in case of a collapse of the building
The ground antennas alone are worth a full episode! Unfortunately very little of this Parkes galore is true and the Dish movie is both historically and technically completely wrong, I hated it. Except for the beautiful views of the dish itself! The Goldstone 210 ft antenna did the Apollo 11 descent (and basically saved the day allowing to maintain LM comms on the omnis). Goldstone 210 also did the TV at the beginning of the moonwalk. They had great signal but they had their scan converter setup completely wrong. You can see it at the beginning, image upside down, way too much contrast, then even inverted contrast while the operator is panicking while trying to correct the mess. So they quickly switch to the 80ft at Honeysuckle (Australia), and the picture gets much better. So Honeysuckle did the beginning of the moonwalk including the first steps on the moon. Soon after that (8m30s into the moonwalk), the Moon came into view of the Parkes 210ft which is further east. Although it was earmarked as backup, it had a 10 dB advantage and therefore a better picture. They stuck with Parkes for the rest of the EVA.
@@CuriousMarc Thanks Marc, always on point, but now I'm disappointed: they can't put so much false informations in a movie that pretends to be historical; at least the part of the telescope operating above the limits for which was built is true, whoever designed it made a great job
@@CuriousMarc Getting science from a movie was kinda the purpose of my comment, ie don't. I liked the movie because it was amusing and had a pretty girl in it. So happy though that it prompted your reply. Thank you.
SMA and N-connectors. I was surprised too to find out how old they are! But they also have the older SMC and you'll see in future episodes I had to spend a fortune on General Radio 900 connectors.
I think Dr Shahriar of The Signal Path said of some microwave device he was reverse engineering "There were so many screws I cried by the end" :) Awesome stuff, Marc, this is another one I'll be following super, super closely. By chance will you be breaking down the Motorola boards to take a look? It would be awesome to see inside them as long as disassembly isn't destructive.
The innards of the 1960s Tektronix 1L20 spectrum analyzer look like a baby version of the transponder. The color of the coax cable jacket is meaningful, the white ones have a resistance wire as the center conductor to help absorb reflections in the 1L20, I wonder if it's the same here.
I remember watching the broadcasts from the moon as a child. Around the same time, I had a pair of walkie-talkies that were limited to 100 mW of power under Part 95 rules. Amazing to think that was the TV exciter for the CSM! IIRC a regular TV transponder used in communication satellites had a bandwidth of 70 MHz FM to send a 6 MHz AM (more precisely VSB) TV channel, trading bandwidth for SNR. And thanks to space deniers and their expressions of personal incredulity, we've had plenty of opportunity to revisit how it all worked once again. Back on the 20th anniversary, I got to learn more than I ever did as a child. No surprise that the boxes were heavy, as a vacuum tube PSU needs lots of copper and iron to get all those DC voltages!
The Power amplifier (i think) that was shut down on Apollo 13 to save power, giving us the noisiest Apollo audio recordings ever. I know the term from the recordings but had no idea what it actually was or looked like.
12:18 "...today Rockwell Collins..." Not since 2018. Collins was sold by Rockwell to UTC in 2018, and Collins Aerospace was tucked under the Raytheon umbrella (which may not have been a brilliant idea, since Collins has forgotten more about Radio comms than Raytheon has ever known; not even close...).
Hi there ! Uffa. Most people go mentally overboard in just understanding WiFi-LAN ... and you are going to but back the Apollo S-band back to work. Hmm. Okay. You need a goal in life ... :-) Waiting for the next episode.
Considering all the trouble that FranLab had with her comms equipment during her recent vomit comet ride, it's understandable that NASA needed something of such sophistication to be absolutely bullet proof, or more aptly, subatomic particle radiation hardened. 1960's cutting edge designs really did lead the way for today's everyday hardware. Thanks for sharing!
The frequency, 2.1 GHz, is rather close to the WiFi and Bluetooth bands. It would be interesting to compare the contents of that first box with a modern solution that's found in something especially tiny like earbuds. The second box is the power amplifier: 11 W I think you said, and could not use transistors. How big and heavy is a modern microwave amplifier capable of that much power?
I found that quite surprising too. TNCs, N-connectors, SMAs are way older than I thought. Military stuff to start with I guess. The transponder is also using SMCs which are still around but that you don’t see much anymore, and the ground test equipment uses the awesome GR-900 which has mostly disappeared - for good reason, it must have cost a fortune to make.
(1) The label isn't wrong about high voltage. Even if the supply isn't very "hot" the signal processing equipment may still contain rather high voltage waveform nodes. (2) FM and PM can be seen as special cases of each other. They aren't radically different between themselves.
All that RG-142 and all those TNC connectors! I'm assuming that cluster of stuff under all that cable is the transfer switch matrix to switch back and forth between the primary and secondary transceivers? Also, are the modulators for the air to ground, telemetry/biomed, and video subcarriers inside these boxes also?
Parkes didn't receive the first five minutes of communications from Tranquility Base, Neil and Buz where to eager to get out and explore the moon, the the honor of receiving the first steps on the moon went to Honey Suckle Creek in Canberra as it was properly aligned to take the signal and Goldstone had an upside down image, as Honey Suckle drop out of alignment, obviously due to the rotation of the earth , then Parkes took up the signal for the next 2hrs. Parkes was not going to be the primary point of the fist communication but it received the honor because of a circuit breaker fire at Tidbinbilla Tracking Station two weeks prior to the landing. Tidbinbilla Engineers where sent to Parkes to set it up to received the signal. Thanks for explaining wait S-Band was, now I know why my fathers skills were needed at the tracking stations Cooby Creek and Canarvon as he studied on microwave technology.
That’s such a bizarre and misleading comment. I never claimed that Parkes received the first minutes of communication from Tranquility Base. The LM was communicating via the Goldstone’s 250 ft antenna (with Madrid as the backup) when it landed. Which was a lucky break: since they had to use the omnis on several occasions, that would have resulted in a mission abort if they had relied only on the smaller primary dishes. Later on, Goldstone, Honeysuckle and Parkes all had reception of the FM downlink signal during the entire EVA. Goldstone had a very good signal and was selected for the first few seconds of EVA TV, but unfortunately, they had their slow-scan converter setup wrong, resulting in the infamous upside down image and bad contrast. NASA realized that within a few seconds and switched to the smaller Honeysuckle antenna for the first few minutes of the EVA. Then at about 8 min into the EVA, the Moon got high enough for Parkes to receive it on the main on-axis receiver (they apparently had it before, but off-axis). They had of course a similar signal to Goldstone due to size. So naturally NASA switched to the Parkes video, which they kept for the rest of the EVA. However they kept Goldstone for the PM uplink transmission throughout the entire EVA. So upvoice (capcom) was from Goldstone the entire time. So all 3 dishes (Goldstone, Parkes, Honeysuckle) received the spacecraft FM data, TV and downvoice throughout the entire EVA. They all got it. It’s just that the TV picture and voice sent out to the broadcasters could only come from one of these sources at a time.
They should add this system to the modern stuff, so we can see live images without issues with buffering and distance (apart from the signal being blocked by Earth)
Interesting....great stuff... my father was a ham radio geek, he always loved Collins gear....but a generic trivia question....did the Soviets use anything even close to this in their Lunar attempt?? Just wondering....
In the same era Soviets did land automatic probes on the Moon, then sent two remotely controlled rovers, and even automatically took and brought back soil samples from the Moon. The details about their electronics are sketchy, but they certainly had similar looking radar/communications dishes on the ground, and were able to measure and control the trajectories of the spacecraft, control them, land them on the moon, drive the rovers, and receive low frame rate video from the moon.
I’d love to know the whole story. I think also originally the LM had no video at all because of weight problems. Eventually they compromised, so the LM could do either PM full data, ranging and voice, or FM with TV, some data and voice. But unlike the CM you can’t have PM and FM at the same time. And the LM would have no recording equipment at all, instead voice and data was VHF’ed over to the CM for recording and relaying to earth!
