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Digizing NASA computer tapes 70's

If you put data onto a spreadsheet I would love to look at it. I love playing with spreadsheets. Can at least summarise the data.

But I do not have knowledge of satellites.
 
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apollo16uvc said:
I have made two videos on it in dutch.
First, a tutorial on how to make your town magnetic viewing solution.
https://www.youtube.com/watch?v=j_kA0cnkBLI


And finally, a video where I visualize the magnetic tracks on 3 tapes:
https://www.youtube.com/watch?v=LAjU2AHIksA

I have attached some photos of the tracks to this message.

I am interested to know if it is possible to determine the frequency of a signal by the macro photos, any ideas?


Macro photos of tracks (Large!)
https://imgur.com/a/rnlJH9P
Click to expand...

Nicely done, Niels!

I like your DIY magnetic viewer :) I worked with mag stripes for phone cards back in the '90's, and I remember we used magnetic viewers bought from some bunch in the UK, essentially a small plastic disk filled with magnetic material that was horribly expensive (at the time).

Regarding the frequency of the signal: looking at your pics, it seems to me that one on the tracks is a mark-space track, ie. a clock track. I would expect something like this on any digital tape format - it would essentially make the data independent of the playback mechanism speed.

If this is the case, then I don't think the frequency of the signal per sé is really relevant.

My guess is that you are going to have to play around a bit (like you seem to be doing) to find the correct speed.

I did find this on cursory searching (not sure if you've cited it yet). Section 3 is quite detailed.
 
apollo16uvc said:
Some interesting new finds, did we play telemetry?


It seems to me quite possible that this is the received data. If we find documents from the relevant satellite with information about telemetry, should it be possible to create a program or circuit that processes the signal?
A program could convert it to a spreadsheet. How much volts the battery outputs every second for example.

I do not know anything about it, but the ESA recordings do not seem to be FM-modulated, since such a wave looks very different.
The NASA recordings are usually not, so apparently AM and FM modulation was not common in recordings from this time.
The NASA documentation usually also has "Direct" recordings and not "FM"

I am looking for people who may be able to help with the relevant satellites, and who are more acquainted with this kind of work.

Niels
Click to expand...

You're looking at the telemetry data, I believe. You're not going to see any FM/AM modulation in any spectrogram of this data. Bear in mind that the modulation technique is just to get the data from point A to point B - there would be no reason to actually record the full RF signal, just the data that is transmitted.

So, now you're just going to have to decode those 1's and 0's :)
 
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