29 May
2013
29 May
'13
11:45 a.m.
After my stupidity it started to run open (chatter) in
local mode as well as
line mode. But this could simply be because two of the fuses blew. I have
Yes, it might well be.
One of the big differences between most UK(Creed) and American (Teletype)
amchiens is that the fobmer use double-current signally (a current one
way for a mark, the other way for a space), the latter use single-current
signally (curent = mark, no current = space). In the case of the Model
33, if the receiving magnet driver loses powre (maybe because the fuse
has blown...), there will eb no current through the receiving magnet and
the machine will 'run open' (or 'space out' or whatever you want to call
it).
new fuses on order and I hope they will be here soon.
It was suggested to me
(and you said it too) that transistors fail faster than fuses and that this
would be an obvious one to test. I thought the voltages I reported to you
were suspicious, didn't you say they indicated it is leaky?
It looks leaky, but it might well be germanium and they tend to leak
anyway.
I am wondering what my first step should be once I get the fuses. Just
turning it on would seem a bit risky. I could do the light bulb trick to
limit current perhaps, someone suggested I do this, but disconnect the motor
as it will try to draw too much current.
I don't think you wil ldo any real harm by fitting the correct fuses and
powering up. There are no custom, delciite semiconductors in a Model 33,
You are not going to burn out the receiving magnet either. The worst that
will happen is the new fuses will blow and maybe some small components in
the manget driver.
Amazingly (given my normal caution) I would fit the fuses, power up and
see what happens.
-tony