Moderators: I am aware that this question in not really on topic. But I place it here as those -if any- who know the answer will read it here.
Do move this if there's a better place for it. I didn't place it in Babbling as it is not meant as a chitchat question, but a genuine detail question about Apollo equipment.

Concerning the Apollo mission:

The tracking stations used amplifiers for their tracking task. According to the website of Audio Equipment company Marantz, NASA used a modified "Marantz Model 9" monoblock tube power amplifier called the 9120 for this task. It was modified to make it even more stable than the Model 9.

I am looking for ANY info on this 9120 amplifiers (how they were used, production numbers, whereabouts, pics, for sale or sold in the past, specs...anything!).

I already asked this question at NASA public contact, so there's no need to mail them again.

A detail question from the sideline of the Apollo project!
Apollo freaks, amaze me and tell me everything you know about what could very well be the best amplifier ever.

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To the regular visitor of internet bulletin boards it is clear that it's an excellent idea your parents get to choose your real name.

Your best bet might be to contact Hamish Lindsay, who was one of the boffins at Parkes/Honeysuckle during that period and wrote Tracking Apollo to the Moon.

Unfortunately I don't have his email address, but if you PM Peter B, he may have it (or that of Mike Dinn, who was deputy director of Honeysuckle).

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"I'd take the awe of understanding over the awe of ignorance any day." - Douglas Adams

Thank you so much. I'll see if I find one of their email adresses. That might bring up more than a mail to the general "public inquiry" mailbox of NASA.

Some people (mainly those with an interest in audio/Marantz) are extremely interested in information on that equipment. I hope to share some space knowledge with them in the process.

Edit: I believe I already found a photo showing the 9120 amplifier. You might not get the big deal, but compare it to finding photo's or information about a modified (improved) saturn5 (say, used for military purposes) that is very badly documented but would be the best launcher ever. The impact is about the same with this 9120 in some audio fanclubs. Edit2: there is so much equipment in those stations, it might very well be another piece of equipment. It has one round gauge in the center as does the Model9, but the gauge seems to be of a different kind, as used in a lot of other equipment in the station. Anyway, if I get the emailadress, I'll sent some pics of the Model9 along, and together with the function description he might understand which equipment I am talking about.

Hamish Lindsay is also one of the persons who dismantled the station after the Apollo era, so if the 9120 got thrown away, I know who to blame for destroying the pinacle of amplifier technology .

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To the regular visitor of internet bulletin boards it is clear that it's an excellent idea your parents get to choose your real name.

No worries, it's fine as is.

At this moment, I am awaiting responses from the Marantz company and NASA. I am still looking for Hamish Lindsay's email adress. I have sent a photo which just might show a 9120 to Marantz, so I can get conformation about that photo from the company that built the 9120. Personally, I seriously doubt that a 9120 is on any photo I have found up to today.

Edit: and i have mailed Honeysuckle's Colin Mackellar. With the same question, and I asked him whether he could pass the question to Hamish Lindsay.

With all these questions asked, at least some info should turn up .

Any members here who can contribute anything: please do so!

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To the regular visitor of internet bulletin boards it is clear that it's an excellent idea your parents get to choose your real name.

Mr Mackellar sent my question to Mr Lindsay.
He could also confirm that the photo did not depict a 9120. Which I could have known, but somehow I didn't see that the caption said "Gemini" instead of "Apollo"...

I'm curious whether Mr Lindsay can give any information on the 9120!

The Marantz company hasn't replied yet, but the contact person just returned from a holiday so he probably has a lot of mail to go through.

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Mr Lindsay remembers the use of a HiFi amplifier. It was a Marantz. So that "has" to be the 9120. It was used to feed the analog 60 Hz Dial clocks (they needed a stable amplifier, so I assume some 60 Hz sine of sorts was fed to the clocks (earth/space?) through this very stable amplifier, which distorted the 60Hz signal as little as possible?).

Mr Lindsay is looking for the Time Standard Engineering Manual of Apollo.

This amplifier was stable enough to be used in Apollo's time standard equipment

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To the regular visitor of internet bulletin boards it is clear that it's an excellent idea your parents get to choose your real name.

A year or two ago I looked at a website with info about the
Mercury, Gemini, and Apollo tracking and communications
stations around the world. It didn't go into such detail as
to talk about individual pieces of electronics, but I vaguely
recall that the person who owned the website was an
electronics engineer. It may have been sponsored by some
electronics manufacturer, but it was not part of any
manufacturer's website. Or it might have been sponsored
by the ARRL or some similar organization. There was a lot
of info. Whoever did it would be a very good bet to give
you a lead. Sorry I don't have a name or URL.

-- Jeff, in Minneapolis

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"The other planets?
Well, they just happen to be there, but the point of rockets is to explore them!"
-- Kai Yeves

Thanks for your interest Jeff Root.

I have not found a site like the one you described.

Mr Lindsay is very helpful, and is looking for all the details he can find.
As the 9120 wasn't that important in the stations, and did not require a lot of "work" (you switched it on et voila), these details aren't that easy to get together nowadays. But we're working on it.

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To the regular visitor of internet bulletin boards it is clear that it's an excellent idea your parents get to choose your real name.

Good luck with your search, Nicolas. I for one am very interested in the outcome - keep us informed!

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"I'd take the awe of understanding over the awe of ignorance any day." - Douglas Adams

I will keep you informed.

I was planning to write an article if I got enough information together, though that would have been on a Dutch site. I'll make a translation!

The article (if it gets written) will be mostly HIFI centered and not Apollo centered though, but I will make clear how and where the 9120 was used.

I hope Mr Lindsay finds more information or can link to other people having in formation. NASA hasn't replied yet. Marantz neither, but they send an out of office reply . So I'm waiting and searching myself...

It's a fun research! Extremely little documentation available, but fun nontheless.

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Small update: I have acquired more information from Mr Lindsay, enough to start writing an article!

I have exams in the meantime, so a bit of patience will be needed from both sides .

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Update:

I have finished the article some months ago. That was an article written in Dutch. The article is now being translated to English by a magazine who requested to publish it.

I hope the magazine finishes this translation in the coming days. Then I'll finally be able to show Mr Lindsay the article I have finished months ago .

When it's published, I'll link to it here as well of course.

What I can say now is that the details of a very remotely Apollo related opbject were correct without exception. This detail goes beyond any possible hoax. All specifications of the amplifier needed for the job fit with the actual Model 9 amplifier (and improved version), with the manuals from different companies, pictures in manuals...it all fits perfectly.

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The article is now translated and published in DIY magazine:

PDF magazine link

The article starts on page 13.

[hm my final corrections seem to be not included, but anyway that's having articles published I guess . Especially the "beauty is in the details" part of the hoax remark was to be more elaborated, next to some style corrections here and there ]

Enjoy!

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A little bit too late for the guys at Honeysuckle. They had their annual reunion a few days ago. Sure some would have liked to read the article.

Harald

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"Flying in space is risky business, but just staying on this planet is risky business too." - John Young, astronaut

Congrats Nicolas. The article was a bit over my head, but was interesting anyway. Nice looking publication too.

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At night the stars put on a show for free (Carole King)

Thanks!

Oh btw, those who can read Dutch can read the original article (hence my own words ) here:

http://www.audiofreaks.nl

(article on top right: "Het hoogste doel: Marantz..."

This article also has higher resolution pics. Mind though, that you need to read the introduction before clicking "lees meer" as it does not show up again in the article window itself (strange software ).

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Blame Mr Horneman .

Too bad it's just too late, but I can't help it. Oh well, this will probably be in the post-reunion mail (you know those mails ) .

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To the regular visitor of internet bulletin boards it is clear that it's an excellent idea your parents get to choose your real name.