Distorted oscilloscope trace

[vic]

Dave Platt wrote:

If the scope was not packed very well indeed (if e.g. it was just
thrown into an outer carton full of styrofoam peanuts)

The packaging was a repurposed LCD panel box, obviously too small for
the oscilloscope, with the device tucked in a corner and various packing
material to hold it in place.

My understanding of Federal law, is that it agrees with what you're
saying of eBay/PayPal policy. When you buy something by mail, it's
the seller's legal responsibility in most cases to get it to you in
good physical condition.

The transaction took place in France, I'm not sure federal law applies
here ;P

v.

 

[Heinz Schmitz]

vic wrote:

The auction did not show the oscilloscope in operation, however the
description said that it was in working condition. While technically it
does operate, that's not what I consider working condition. I only paid
40 euro though, so I think I won't bother with the procedure, especially
if I have to send it back to the seller, with proper packaging this
time. I'll probably save some more and buy a recent model one day.

This is a very wise decision, imho. I think, that on-line purchase of
fragile goods and delivery by mail always carries a considerable risk
of receiving the article damaged - be it, because the sender broke it
before or while packaging, because he packed it not well enough,
because the delivery service threw it around, because a heavy other
parcel was thrown onto it, or because the buyer dropped it himself
while carrying it to his workbench, or because of something else.

In the end, the problem imho is, to prove to the judge without doubt,
what really did happen.

The solution I prefer is, to buy such goods from sellers located near
to my place, so I can drive over, eventually have it shown to work,
and to bring it home myself. This way, I often meet nice people, too.

Regards,
H.

 

[Heinz Schmitz]

vic wrote:

Just to give some feedback, I tested the deflection plate voltages and
power supply and they look correct to me. So I'm a bit pissed off that
an otherwise working device was destroyed by careless handling on the
part of the sender. I guess my current very old, unreliable and
completely decalibrated oscilloscope will have to do a little longer

If you think that everything else of the scope is ok, then why not sit
at the bank of the river and wait for a replacement crt to swim by?

Or even walk into the river and stir up one from the bench of some
replacement guru? In such cases I find we are really blessed with
the internet .

Regards,
H.

 

[Jim Yanik]

vic <news@bidouille.org> wrote in
news:4a08c64a$0$5367$426a74cc@news.free.fr:

Dave M wrote:
scope, that will make your troubleshooting a LOT easier. If you
don't have a service manual, you really should get one. You can buy
a digital copy from http://artekmed.startlogic.com/page2.html for
$10.00. Artek sells high quality scanned copies; I can recommend
them from personal experience.

I never buy from this kind of shop since their business model seems
dodgy to me. Basically they sell copyrighted works of others, and
stuff that is sometimes freely available elsewhere.

v.

TEK has released their copyright on obsolete products.
So,the company provides a service,at a price.

--
Jim Yanik
jyanik
at
kua.net

 

[JW]

On Fri, 08 May 2009 22:18:43 +0200 vic <news@bidouille.org> wrote in
Message id: <4a0493a2$0$6733$426a74cc@news.free.fr>:

Hi,

I recently bought an oscilloscope on eBay, and I don't know if the
seller lied in the description or if it was damaged during the
transport, but the trace is completely distorted and shows strange
grid-like patterns. I made a few pictures and a little video :

http://img222.imageshack.us/img222/1984/focused.jpg
http://img212.imageshack.us/img212/6566/unfocused.jpg
http://www.youtube.com/watch?v=c5RTaTM0tJk

The shape of the trace changes when I change the y-position dial. This
makes me think the problem is in the tube and not in the electronics.

I'm wondering if this could be caused by a bent grid somewhere in the
tube ? Could it have been damaged if the oscilloscope received a shock
for example ?

I think the tube is pretty much toast, as well as the scope since there
is no way I could find a replacement tube (Tektronix 2225), but I
wouldn't mind to be proven wrong Thanks.

Shoot an email or phone someone at https://www.techrecovery.com/
We have lots o' dead Tek scopes that are not worth repairing. Dunno what
they'd charge for the tube, but $75 + shipping sounds reasonable to me.
Tell them Jay sent you. Just do a bit of homework first and find out what
other models share the same tube (So I don't have to do too much digging)
and have the Tek part #. Make sure you put that info into your query.

 

[JW]

On 12 May 2009 12:10:35 GMT Jim Yanik <jyanik@abuse.gov> wrote in Message
id: <Xns9C09533438AA2jyanikkuanet@74.209.136.87>:

vic <news@bidouille.org> wrote in
news:4a08c64a$0$5367$426a74cc@news.free.fr:

Dave M wrote:
scope, that will make your troubleshooting a LOT easier. If you
don't have a service manual, you really should get one. You can buy
a digital copy from http://artekmed.startlogic.com/page2.html for
$10.00. Artek sells high quality scanned copies; I can recommend
them from personal experience.

I never buy from this kind of shop since their business model seems
dodgy to me. Basically they sell copyrighted works of others, and
stuff that is sometimes freely available elsewhere.

v.


TEK has released their copyright on obsolete products.
So,the company provides a service,at a price.

Yep. Additionally, Dave's manuals are of very high quality. Many of them
are text searchable unlike the free online versions. Very useful when the
manual is 600 pages in length.

 

[Smitty Two]

In article <4a0493a2$0$6733$426a74cc@news.free.fr>,
vic <news@bidouille.org> wrote:

The shape of the trace changes when I change the y-position dial. This
makes me think the problem is in the tube and not in the electronics.

This makes me think there's dirt in the selector switch. Spray a little
DeoxIT in there and run the switch back and forth several times.

 

[Jim Yanik]

Jim Yanik <jyanik@abuse.gov> wrote in
news:Xns9C09533438AA2jyanikkuanet@74.209.136.87:

vic <news@bidouille.org> wrote in
news:4a08c64a$0$5367$426a74cc@news.free.fr:

Dave M wrote:
scope, that will make your troubleshooting a LOT easier. If you
don't have a service manual, you really should get one. You can buy
a digital copy from http://artekmed.startlogic.com/page2.html for
$10.00. Artek sells high quality scanned copies; I can recommend
them from personal experience.

I never buy from this kind of shop since their business model seems
dodgy to me. Basically they sell copyrighted works of others, and
stuff that is sometimes freely available elsewhere.

v.


TEK has released their copyright on obsolete products.

I should have typed "obsolete product manuals".
sorry.

So,the company provides a service,at a price.

--
Jim Yanik
jyanik
at
kua.net

 

[Boris Mohar]

On Tue, 12 May 2009 02:54:27 +0200, vic <news@bidouille.org> wrote:

Just to give some feedback, I tested the deflection plate voltages and
power supply and they look correct to me. So I'm a bit pissed off that
an otherwise working device was destroyed by careless handling on the
part of the sender. I guess my current very old, unreliable and
completely decalibrated oscilloscope will have to do a little longer

v.

You may have some debris lodged inside the electron gun. Tap on the neck of
the CRT and see if the trace changes. Maybe you can apply some rough handling
of your own.

--
Boris