Tektronix 545B (VI)
JOSE V. GAVILA (EB5AGV/EC5AAU) <eb5agv@...>
First, forgive me for my dumbness; I forgot to upload the last picture!. I
have done it, along some other pictures... as the oscilloscope is now
WORKING!!!. Not at 100%, but lots better than before. You can look at these
pictures for the current images:
Close view with a " 'B' INTENSIFIED BY 'A' " trace of the calibrator
signal. Despite the picture, traces are actually very sharp:
This is the one I missed last time:
So, as you can see, the 545B is finally going back to life!. And which was
the fault, you will ask?. An electrolityc can, of course!. But (thanks
Stan!) not the one I had looked but another a bit more hidden (not too
much; I just missed it). It is a 125uF can. As I had none similar, I have
temporarily put a 47+22uF 450V capacitor pair so it is a bit under specs
but, until I get a convenient one, it does its work. Ripple is now close to
the 5mV nominal value.
I have also put a fuse holder and an slow blow 3A fuse (we have 220V/50Hz
power here in Spain, so the fuse rating). So far I have just added this and
a new power switch (which was faulty, about 6 Ohm closed; it got really
hot) along the couple caps. Basically, the oscilloscope seems to have few
tubes changed, a couple diodes and some resistors. Not bad for a 30+ years
old scope!. BTW, I think this one dates from 1968, same year I was born. So
it is still young :-)!
Now I have located a fault in the TIME BASE B. If I put TRIGGER in AUTO or
DC, it does not work. It does in AC position, so I will look at this in the
manual. Of course, hints welcomed!
Also, the 1A1, whilst worksm has the usual microphonic nuvistors... but at
least they work. Both channels are fine and, after some contact cleaner,
all controls do they intended function.
Well, for my first tubed Tektronix work, I am really happy with the results
so far. Now I hope to get some plug-ins... any available?
Thank you all for your help!
73 EB5AGV / EC5AAU - JOSE V. GAVILA
La Canyada - Valencia (SPAIN)
EB5AGV Vintage Radio Site: http://www.geocities.com/eb5agv
European Boatanchors List: http://groups.yahoo.com/group/euro_ba_swap
Stan or Patricia Griffiths <w7ni@...>
Hello Jose,toggle quoted messageShow quoted text
I am glad you found the bad cap. I am sure I have an exact replacement for the
125uf cap you need. How can I send it to you?
JOSE V. GAVILA (EB5AGV/EC5AAU) wrote: