Hi Andy,
You asked about connectors for extender cables. There are three possible
extenders you could be talking about: 1) vertical plugin, 2) timebase
plugin, 3) power cable from mainframe to power supply. I am sure I have
connectors that I can sell you to build extenders for either type of plugin
for a couple of dollars per connector. Most of what I have have been
salvaged but are still perfectly useable. In the Tektronix Service Center
we had an extra long power supply cable that made it much easier to turn the
555 on its side for maintenance. Let me know if you need some connectors to
make extenders.
You also asked me how many old scopes "blew up" :-) on turn on. No
explosions that I can recall, but some came quietly on but did not work
completely.
Stan
_____
From: TekScopes@... [mailto:TekScopes@...] On Behalf
Of faustian.spirit
Sent: Friday, December 29, 2006 6:38 PM
To: TekScopes@...
Subject: [TekScopes] Re: Bringing up a 555
--- In TekScopes@yahoogrou <mailto:TekScopes%40yahoogroups.com> ps.com,
"Stan and Patricia Griffiths"
<w7ni@...> wrote:
Hi Andy,
Others may call me careless in my approach to firing up an old 555,
but I
would just plug it in and turn it on. It is pretty well fused and I
would
not expect any to blow anyway.
Probably will soon... Visual inspection shows nothing suspicious at
least... I could put the L and CA in, but now I feel obliged to at
least try to recalibrate or fix the D (was marked "broken" but seems
to work except that the gain is too low and the CMRR is lousy... Most
of the switch trouble vanished after applying some Tuner 600) ...
whoever designed it had money in the plugin extender business I guess
:) And something with the idea of operating a 500 series lying on its
side strikes me as very odd... same with sawing a hole in the table...
Are the connectors needed to make an extender cable as rare as those
in the 551/555 PSU cable are said to be? I noted the pitch is
different....
You can not test the power supply disconnected from the scope and your
reason is correct. It must have a proper load on it and, yes, you
will need
all plugins in place to put a proper load on the power supply. Both
timebases and both verticals.
On old Tek scopes, I never bother to reform the electrolytics. A
shorted
one is very rare and an open one will show up as too much ripple
somewhere.
I have never seen a shorted one do serious damage.
Over the past 46 years, I have probably turned on more than 1000 of
these
old scopes. I have lost count but I have at least six or seven
555's in my
collection . . . maybe more.
How many blew up? :)
I think when originally shipped from the factory, the serial number
of the
power supply will match the serial number of the mainframe.
Sometimes in
the field, mainframes and power supplies get swapped around, but I can't
remember any serious incompatibility problems, even with mismatched
serial
numbers.
Stan
