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I am looking for one B1107, 'Power On' indicator bulb, for the Tektronix 453
that I am trying to fix.
The Tek part number is 150-0045-00.
Does anyone have one that they would like to sell me or can anybody suggest a
place
to buy a replacement? The bulb appears to be a custom built bulb and may be
pure
un-obtainium. :(

Thanks.

73 de N1FBZ

Shortly before leaving Tektronix, I wrote a good app note on making floating
measurements, related to SMPS. That was 20 years ago, I don't think Tek still
has it on the web site. I will try to find the original file and post it. We
made several real measurements in the lab for research in the paper. Floating
instruments, isolators, and differential measurement techniques were compared.
Without rehashing the entire note, a summary is that for most applications,
differential measurements give the best results.
Subtracting channels is a differential mode of operating the scope. Compared
with a true differential amplifier or probe, channel A minus channel B has
much poorer CMRR at higher frequencies. The other major limitation is common
mode range. The common mode is the voltage you are floating on. IT is
limited to the full scale of the scope at the V/DIV setting you are using.
This is a real limitation in SMPS work when you need to measure small voltages
riding on top o flarge voltages. The common example in higher power inverters
is measuring the upper gate drive in a push-pull drive stage. The upper gate
only has a few volt (15 maximum) swing riding on a 350V swing. To keep the
common mode (350 V swing) within the common mode range, you need to set both
channels to 50 V/div. IT is difficult to see the gate drive with a 5 to 15 V
swing with the scope set to 50 V/div.

Steve

What is the source of the signal being displayed ?
What kind of probe is being used ?Is it compensated ??Is the probe ground lead
connected ?
Do yourself a favor & lose the probe.Connect to a decent signal source, via
coax, using a 50 ohm termination at the scope end.

HankC, Boston

You may address me as Ron, or Mac (for machineguy). I usually use Mac on the net and Ron in the "real world". >As a brief introduction, I am 78 years old, retired electronics engineer, now hobbyist, living in Iowa, USA.

Seeing that are both channels are essentially the same just seems weird to me.

I would think that it's the moderator's responsibility and no one else
(elders or otherwise) to filter the various threads. There are certain
topics that are completely off topic like politics and should be cutoff.
But, there are others that are technical and very informative which are
gleaned from years of experience that allow us to pick up information that
is very helpful. I welcome those. So, you need to have a jeweler's eye!

John Justin

On Mon, Jun 18, 2018 at 1:17 AM, Jeff Urban <JURB6006@...> wrote:

Bit odd you bring this up now when I just got through posting in a thread
about 2 sided boards, and that went into some other things. My experience,
someone else about car radios using the same manufacturing methods and all,
one with their own stereo unit the fixed by fixing a 2 sided board.

Now there's some thread drift forya, but it is still pertinent to the
subject. Of course WW2 is not. I have a group and I was thinking what I
would do. I would probably get in there and say "this one can slide, but
anymore of this political shit and we are talking action, I do not want it
here". And that it makes enemies easier than it makes friends.

But now there is the Fluke 3300 thread. That is not a Tek scope. I have
no problem with it, I think maybe they could have been spurred on to my
group but there are not enough members now to be sure to get anything good
back. If that is close enough to on topic fine. Good that you don't want to
stifle.

I think the thing here is that in moderating these, you can't just grind a
line into concrete. That's why we have human moderators. (and judges and
whatever)

You could send some to my group, which I made specifically for other test
equipment. But I don't want anyone forced. I don't want to force anyone to
do anything. Not the WW2 thing though.

Put it this way, I may respond in threads that go political, but I will
never start one. I have more respect than that.

On Mon, Jun 18, 2018 at 12:34 am, Albert Otten wrote:

With curves like this
/g/TekScopes/photo/59361/1?p=Name,,,20,1,0,0 I wouldn't
even bother to calculate a rise time. Obviously the main problem is roll-off. I
would search the manual for Adjustments which influence that nanoseconds
part of the curve and try these first.

Ok. I will start turning screws. I just wanted to get opinions on whether this
could possibly be a problem with a bad component prior to messing with the
calibration. I would hate to have a bad transistor or capacitor causing the
bad rise time and start turning the adjustments and mess up something that was
actually already set correctly.

Bit odd you bring this up now when I just got through posting in a thread
about 2 sided boards, and that went into some other things. My experience,
someone else about car radios using the same manufacturing methods and all,
one with their own stereo unit the fixed by fixing a 2 sided board.

Now there's some thread drift forya, but it is still pertinent to the
subject. Of course WW2 is not. I have a group and I was thinking what I
would do. I would probably get in there and say "this one can slide, but
anymore of this political shit and we are talking action, I do not want it
here". And that it makes enemies easier than it makes friends.

But now there is the Fluke 3300 thread. That is not a Tek scope. I have
no problem with it, I think maybe they could have been spurred on to my
group but there are not enough members now to be sure to get anything good
back. If that is close enough to on topic fine. Good that you don't want to
stifle.

I think the thing here is that in moderating these, you can't just grind a
line into concrete. That's why we have human moderators. (and judges and
whatever)

You could send some to my group, which I made specifically for other test
equipment. But I don't want anyone forced. I don't want to force anyone to
do anything. Not the WW2 thing though.

Put it this way, I may respond in threads that go political, but I will
never start one. I have more respect than that.