[GreenKeys] TT-7/FG Restoration

[Russell Handorf]

Howdy do to everyone-

I've acquired two full kits that are the TT-7/FG versions of the
teletypes. Manuals, tables, reperfs, perfs, keyboard, printer, and power
supplies in all. I've started cleaning one of the keyboards and printers
without problems and have it working again. Motor spins fine, no issues
seen electrically from there. I was able to get it to talk with itself
doing a loopback with a 10k 1W resistor and 120VDC 5mA limited power
supply on that line. While a minor achievement, it certainly feels great
to have it working. I have some questions, thoughts, concerns,
observations that I'm hoping to get some advise from ya'll folks as I go
down this journey.

The first question/observation I have is:
I did notice I have to power the tape perforater and character counter
separately if I want to engage those. From the schematics, it appears
they are separate from the data loopback line. I'm just double checking
if anyone has guidance/experience with this observation. To get the
printer, perforater and character counter to work, I have one circuit
powering the keyboard/printer via a DC loop, and I have a separate DC
feed going into 24/25. All in all, "am I doing this right?" is the
bigger question.

The second one is I've started working on the re-perforater. The unit I
have has the 4 pin AC plug, and two phonojacks. I managed to clean it up
pretty well, but I'm in the process of re-writing the 4 pin AC plug to a
modern plug. Reading the schematic on how the table is wired, one of
those looks like its a "floating dead lead." But when I look at the
base, I believe it's connected into the giant filter that's in the
bottom of the base. Unfortunately, I cannot find the manual or schematic
for this part of the kit in the doc's that came with it. Does anyone
have any experience they can share about how to rewiring it for a modern
NEMA-5-15 plug?

Third question relates to the power supply. I have three power supplies
that came with all the gear; two of the normal big "three grunts to
lift" back breakers and one that's half the size. Between all of them,
no tubes. I'm not putting a lot of stock in being able to revive them
without being able to replace the mercury vapor tubes or neon lamps. I'd
be interested in knowing where a good part supplier is, but there's an
additional reason for not taking much interest in repairing them and it
has to do with their operational safety. Which leads me to the question
of, what alternative power supplies are folks using these days? Straight
AC to DC 120V with smoothing caps and the like? Boost converters?

The last question I have has to do with some fun with the machines. Yup,
I'm looking to plug them into a raspberrypi and then going into the
wilds of getting them onto the Internet one way or another. I've seen a
couple of schematics, gizmo's and gadgets that folks have made. I don't
think there is anything readily "in stock", but I am curious as to what
everyone has made a decision on using. Part of me wants to spend some
time trying to make a modification to a board I saw that uses a boost
circuit. But before I go re-inventing a wheel, I'd like to know what
works, what hasn't, and noodle on it a bit more.

Thank you for your time in reading this message. I'm extremely excited
to be working on these machines and getting them going again.

Cheers

Russ