On 25 January 2016 at 12:34, John Clark johnclark05@... [TekScopes]
<TekScopes@...> wrote:

No, it's not you. I've found the same smell in the two items I've ordered
too. It's pretty bad.

​One of the items is a fan for my 2445A. The smell isn't too strong at the
moment - hopefully when it's installed, warmed up and blowing it doesn't
become noticeable. It's not very professional :(

Malcolm​


[Non-text portions of this message have been removed]

Lol, we had a very small electronics mail order here, over the years
you could smell how his habit increased.
The man is out of business now.

Better be careful or they'll get you for not paying the import duty on
your tobacco products ;-).

ST

On Mon, Jan 25, 2016 at 1:34 PM, John Clark johnclark05@...
[TekScopes] <TekScopes@...> wrote:

No, it's not you. I've found the same smell in the two items I've ordered too. It's pretty bad.

John

Sent from my BlackBerry 10 smartphone.
From: Malcolm Hunter malcolm.r.hunter@... [TekScopes]
Sent: Monday, January 25, 2016 07:01
To: TekScopes@...
Reply To: TekScopes@...
Subject: [TekScopes] OT: QService components


Hi,

Has anyone else ordered items from QService in Greece? I just received my
first order from them and everything smells of stale tobacco smoke. Is it
just me?

Malcolm










------------------------------------
Posted by: John Clark <johnclark05@...>
------------------------------------


------------------------------------

Yahoo Groups Links

Putting the smelly stuff into a bag with some (cheap!) coffee powder (I
used cheap coffee ground very finely, like espresso, to great success)
for a week or two usually helps.

Pro: Doesn't smell like tobacco anymore
Con: Tends to smell like coffee

Some plastics take longer than others. One of the used Weller tools I
bought took nearly a month in the bag until the silicone cabling didn't
smell like a chainsmoker anymore. Replacing the coffee powder every week
helps, too.

Cheers,
Marian

PS: Yeah, in a town nearby there was also a small electronics shop
operated by someone you could easily confuse for a chain-smoking Gimli.
He was very nice and would always help you troubleshoot circuits and
kits right on his counter. I think he died a few years ago :/

On 1/25/2016 7:00 AM, Malcolm Hunter malcolm.r.hunter@...
[TekScopes] wrote:

Hi,

Has anyone else ordered items from QService in Greece? I just received my
first order from them and everything smells of stale tobacco smoke. Is it
just me?

Hello--

You might try placing the fan in a sealable plastic bag along with some
sheets
of unused fabric softener as used in clothes dryers. Another approach
substitutes
ground coffee (contained in a mesh bag) for the dryer sheets. Buy cheap,
strong,
severely-roasted coffee and discard after a few days. Both methods work with
stinky books.

73--

Brad AA1IP

I've ordered from them with no problems. I assume what you got was a spare part pulled from an older piece of gear (as that's a lot of what they sell). I figure they don't take time to clean/restore items like that and the residue is from the item's past life.

Of course, if this were something like a knob, etc., any residue would be fairly easy to remove and a fan might be a bit more difficult. Good luck with it.

Thanks,
Barry - N4BUQ

On Mon, 25 Jan 2016 10:18:09 +0000, you wrote:

On 25 January 2016 at 00:45, John Dickens jake_117_dickens@...
[TekScopes] <TekScopes@...> wrote:

It would be my first scope with a microprocessor. I also have a 7603 and a
2236 as well, not to mention a 503 in poor shape.

?The 2236 has a 6802 microprocessor, so the 2247A won't be your first. Or
do you mean something else?

Malcolm?

I almost posted the same thing but decided that he meant
microprocessor controlled.

On Mon, 25 Jan 2016 12:00:48 +0000, you wrote:

Hi,

Has anyone else ordered items from QService in Greece? I just received my
first order from them and everything smells of stale tobacco smoke. Is it
just me?

Malcolm

I noticed the same thing. The strong smell of tobacco reminded me of
my grandfather.

Hi David,

You are right, two large paper caps on the AC board have burst open - those were the bangs I heard. The main rectifier caps (in the black plastic holders) seem to be okay. I'll need to research the current limiter you mentioned. In your experience, should I replace all the capacitors like some people have advocated on Youtube or just the two broken ones?

On 25 January 2016 at 14:01, Barry n4buq@... [TekScopes] <
TekScopes@...> wrote:

I've ordered from them with no problems. I assume what you got was a spare
part pulled from an older piece of gear (as that's a lot of what they
sell). I figure they don't take time to clean/restore items like that and
the residue is from the item's past life.

Of course, if this were something like a knob, etc., any residue would be
fairly easy to remove and a fan might be a bit more difficult. Good luck
with it.

​I received several items, all individually sealed in grip seal bags. They
all have a faint whiff of smoke and the jiffy bag it was shipped in smells
of smoke too. ​I'm not too bothered as long as I it's not too pungent when
the fan is fitted and running. It's just disappointing - not what you
expect from a business these days.

Malcolm


[Non-text portions of this message have been removed]

I have also purchased stuff from Qservice. It was a brand-new knob and
didn't smell at all; neither did the Ziplok bag. It turned out to not be the
correct knob, but that's another story...

David, I do hope that you mean that your grandfather was a smoker, not a
humidor! Just joking..

Colin.



From: TekScopes@... [mailto:TekScopes@...]
Sent: 25 January 2016 14:14
To: TekScopes@...
Subject: Re: [TekScopes] OT: QService components





On Mon, 25 Jan 2016 12:00:48 +0000, you wrote:

Hi,

Has anyone else ordered items from QService in Greece? I just received my
first order from them and everything smells of stale tobacco smoke. Is it
just me?

Malcolm

I noticed the same thing. The strong smell of tobacco reminded me of
my grandfather.

If the +65 volt supply is actually +60 volts, then that explains why
all of the other supply outputs are slightly low. They all directly
use the +65 volt supply as a reference so there is no mystery there.

Interesting the other half U1724A both inputs are 4.5 should be 8.9. Output 5.1 should be 8.3. And the Vcc is also 4.5. The reference voltage from VR1726 is correct enough at 9.3.

If the output of U1724B was driving Q1752 and Q1756 hard, like 8.8
milliamps hard which is within the output current limit of a 1458,
then Vcc would be pulled down causing problems with the +65 regulator
as well so I think we are looking at a problem with just the +15 volt
regulator. C1757 which you identified is the prime suspect. From the
Tektronix 466 parts list:

10uF 25V 20% 90201 TDC106M025FL Mallory

http://datasheet.octopart.com/TDC475M035NSF-CDE-datasheet-110389.pdf
http://www.cde.com/resources/catalogs/TDC.pdf

I was originally suspicious of a socket but now I think it was Colonel
Mustard, in the Conservatory, with the Candlestick. Err, I mean the
solid tantalum capacitor, in the +15 volt regulator, with a short.

There might be a short somewhere else on the +15 volt supply but
removing C1757 is the place to start. If you have a 10uF to 100uF
aluminum electrolytic capacitor laying around it can be used in its
place.

All voltage measure slightly low but the +15 is way down to 1.4V. Unregulated +15 is slightly high 25.9 vs 22.5 presumably because of no current through pass regulator Q1756.

Is it possible that the 10uf cap to ground at the + input [actually +15 volt output] is bad pulling that input down?

Given the above, this could be the whole problem. A shorted C1757
will pull the +15 volt output down, Q1754 will then limit the current
by pulling the output of U1724B down and that will cause Vcc of U1725B
to be pulled down.

On 25 Jan 2016 03:57:16 -0800, you wrote:

Thanks David for the input. Yes, I was thinking of the .02uf at the input but wrote the 10uf on the output. My bad.

The 65V is around 60V and adjustment is non-reponsive; but that is to be expected since U1724 is not working. No sockets on this board. So I'm going to check the supply to U1724 - R1727 and VR1725 and the U1724 itself.

[Non-text portions of this message have been removed]

Hi David,

From 15 V to 28 V seems a rather small change compared to the data in the calibration section. Maybe you set the time base for a slow speed that activates the Intensity Limit?
Albert

============

With Q1107 (a slow 2N3904???) removed on my 7603, the output at point
B is 14.8 volts which closely agrees with our current calculation so I
wonder if Marian's <public@... mailto:public@...> measurement of 20 volts at the
output of the z-axis amplifier is significant and indicates a problem.
I get the same 14.8 volt output with Q1107 installed, the readout off,
and the intensity control turned to minimum.

I also measured the output at point B and as the intensity control is
turned fully clockwise, the output increases to about 28 volts
monotonically.

The oscilloscope does not need the AC line capacitors to operate so I
would remove them for now and verify that there are not other
problems.

The inrush current limiter, RT1016, is *after* the capacitors so check
the condition of the fuse.

The best deodorizer is hydrogen peroxide solution - it works on most organic residue (even skunk juice). Just put some standard 3% H2O2 solution in an aerosol pump spray bottle and mist it onto the surfaces, then wipe and air-dry the item thoroughly before use.

Ed

Those paper AC line X-caps have been the subject of much discussion here and on the hpagilent group. They are the ones potted in amber colored epoxy, usually WIMA or RIFA brand. The bottom line is that they should be eliminated whenever encountered - even if not already failed - and replaced by proper X-rated plastic-dielectric caps. This is especially important in high line voltage (~240V) countries, where the caps are operating near their limit.

These are also used inside of some packaged line filter assemblies, and known to have caused internal failures there.

Ed

Hello All,


I am getting ready to wrap-up my first year at the University of Akron and was hoping someone here might know if Keithley Instruments in Solon, Ohio has any co-op positions. I know they were bought by TEK a few years back, but do not know if those intern opportunities went to Beaverton or elsewhere. Any help or guidance would be greatly appreciated.


Cheers,


David

I'd recommend looking to see if there's a Tek/Keithley design or manufacturing operation listed there locally and contact them, rather than starting at Tek HQ. If there's a Tek field office nearby, someone there should know. Also, the university should have info about local opportunities.

Ed

Thank you Ed. I have checked with the university staff and career office, but they do not know of co-op’s with the local TE firms, all mostly Danaher. Do you know of anyone in this industry local to me who might offer direction?

Cheers,

David

I did not realize the 2236 has a 6802.

Thanks for your comments, David and Malcolm.

John

Hi Malcom,
I have bought from them several times and never encountered a tobacco smell.
I would have remembered if I had, since I have been a non-smoker all my
life. My dad was a lifelong cigar smoker and I can't stand the smell of
cigars to this day. Apparently we have a lot of non-smokers in the forum
judging from the comments I am seeing.

Someone else mentioned QService is out of business but I don't think that is
the case since they are still selling on Ebay and they have an active web
site at
http://www.qservice.eu/

Dennis Tillman W7PF