Date   

Getting really, really tired of...

tmillermdems <tmiller@...>
 

Ebay sellers that stick a 475A scope in a box that is too small. In this last case, it was smaller than the scope and the knobs were poking through the cardboard. Both trigger and slope knobs bent 60 degrees, shafts snapped, knobs broken. Var vert gain (ch-2)pushed in and broke the control mounted on the board.

Other than that, the scope was perfect and very clean. Just had a shorted cap on the -8 volt supply.

FWIW,

Seller:
megasupersurplussales

If you buy from them, be sure to specify how you want it shipped.


Very unhappy and needing to rant a bit,
Tom


Transformer specs

Glenn Little
 

While cleaning the shop, I uncovered a Tektronix power transformer.
This is marked 120-0344-00.
First indications are that this is from a 545B.
Can anyone verify this and possibly provide voltages and currents?

Thank you
73
Glenn
WB4UIV


Service manual with schematics (or schematic section) for TAS465/475/485

Sam Reaves
 

Does anyone know where I can find a service manual with schematics
for the TAS series?
I have a manual for the TAS485 but it is missing the entire schematics section.

Thanks,

Sam
W3OHM


Re: Best electrolytics for recapping (2235)?

jtjewell83
 

There's also the counterfeit caps to watch out for.   Here are a few links:

http://en.wikipedia.org/wiki/Capacitor_plague

(see the last picture, near bottom, right side  "...stencil clarity between new Nichicon from reliable vendor, and bad taken from malfunctioning Dell Optiplex GX270 computer")

http://spectrum.ieee.org/computing/hardware/bogus

Then, of course, there's the (bad) stolen formula talked about on the above wikipedia page and here:

http://home.earthlink.net/~doniteli/index27.htm

and 1000's of other web pages on the net.

I will  stay with the Panasonic FC and FM.  They've served me well for many years.  I have replaced many bad Nichicon and Rubycon caps in older consumer electronics.  The FM series are 2K to 7K hour caps. 

I don't work for Digikey or Panasonic.

Jimmy J.


--- In TekScopes@..., "Steve Hogan" wrote:
>
> Bernice commented that the Panasonic caps had problems.
>
> I have a friend who had a disaster using
>
> United Chemicon SXF Radials 330uF/25V
>
> 1000uF/35V Radial SXF SXE LXF.
>
> Their KME series large diameter never leaked.
>
> 2200uF/35V by NIC Nippon Industries corp also leaked.
>
> For that reason I routinely remove and replace any United Chemicon radial
> lead electrolytic that I find.
>
> The Leaking SMT caps (10uF/35V) on the Front Panel PCB of my Tektronix AM700
> were United Chemicon.
>
> The SMT caps on the DSP board were also United Chemicon, but they were not
> leaking.
>
>
>
> So far I have had no leakage from Panasonic FC, FM or Nichicon HE caps.
>
>
>
> I think this goes to show that it can happen to anyone. Notice how the
> makers of Disk drives have all taken turns making bad ones at one time or
> another. Perhaps this is an indication that nothing in this world is
> perfect. We can just do the best we can to avoid using caps with known
> problems.
>
>
>
> Steve
>


Re: Best electrolytics for recapping (2235)?

tss_steve_990
 

Bernice commented that the Panasonic caps had problems.

 

I have a friend who had a disaster using

 

 

United Chemicon  SXF Radials  330uF/25V

 

1000uF/35V  Radial  SXF SXE  LXF.

 

Their KME series large diameter never leaked.

 

2200uF/35V  by NIC  Nippon Industries corp also leaked.

 

For that reason I routinely remove and replace any United Chemicon radial lead electrolytic that I find.

The Leaking SMT caps (10uF/35V) on the Front Panel PCB of my Tektronix AM700 were United Chemicon.

The SMT caps on the DSP board were also United Chemicon, but they were not leaking.

 

So far I have had no leakage from Panasonic FC, FM or Nichicon HE caps.

 

I think this goes to show that it can happen to anyone.  Notice how the makers of Disk drives have all taken turns making bad ones at one time or another.  Perhaps this is an indication that nothing in this world is perfect.  We can just do the  best we can to avoid using caps with known problems.

 

Steve

 

Steven A. Hogan

The Sound Steward

1606 West Southgate Avenue

Fullerton, CA  92833-3851

www.soundsteward.com

(714) 871-6636 phone

(714) 904-6636 cell

(714) 871-0640 fax

 


From: TekScopes@... [mailto:TekScopes@...] On Behalf Of Bernice Loui
Sent: Saturday, July 02, 2011 9:05 AM
To: TekScopes@...
Subject: Re: [TekScopes] Best electrolytics for recapping (2235)?

 

 

Some years ago Panasonic had low impedance series that leaked about a year or two in service. They dis-continued this series and every company that used them had a product liability problem.

Since then, I have stopped using Panasonic capacitors in any designs.. Due to the easy availability of Panasonic parts at Digi-key, they have become common, but they are not always the ideal choice. This is a marketing strategy that has worked well for Panasonic.

My perfered has been United Chemi-Con, Nichicon or even CDE.

The specific type of 'lytic that should be used depends on the it's specific job in circuit. There is not real one 'lytic does all. Be aware of life, temperature, specified temperature and other ratings before installing any replacement 'lytic.

Yes, most of the time.. just replacing will work. but that is not proper engineering practice.


Bernice 

--- On Sat, 7/2/11, ab1jx wrote:


From: ab1jx
Subject: [TekScopes] Best electrolytics for recapping (2235)?
To: TekScopes@...
Date: Saturday, July 2, 2011, 6:45 AM

 

I've got some 11 khz ripple in the vertical section of my 2235 so I was thinking about recapping it. I saw Rubycon mentioned in another thread, I was thinking Panasonic EEU line or maybe Nichicon. Is there one all-around best choice or does it depend on where it is in the scope?

Alan


Re: User On-Screen Text

 

--- In TekScopes@..., MailGate <mail_gate@...> wrote:

Dear group,

some (old?) Tek scopes allow the user to display ASCII - Text on the CRT.
This is nice, if you review your screen shots of the day and have some
background information of the measurement right on the plot.

Since "modern" scopes can save directly to floppy disk, there is only
one way to store additional info: using a nice file name.
Does someone know, if there is a feature on modern scopes (TDS 6xx, 7xx)
to display ASCII text on the CRT?

Best,
Simon
-----------
Try this MESS:SHOW "THIS IS A TEST" This will show a message box
with text on the default locations. You may alter the location and
size of the box with MESS:BOX X1,Y1,X2,Y2 where X are the horizontal
coordinates (0-640) and Y are the vertical coordinates (0-480) of the
box. To turn off the message use MESS:STATE OFF
As far as I know this is only available via GPIB.
/Håkan


Re: User On-Screen Text

fjh001
 

The DSA601/2 enables to write text using a GPIB command (I'm not sure now if also through the menus), so surely modern ones have a similar instruction - but I suppose that this must be checked with the correponding programmer's manual.

Regards,

Javier

El 05/07/2011 20:25, MailGate escribiᅵ:

Dear group,

some (old?) Tek scopes allow the user to display ASCII - Text on the CRT.
This is nice, if you review your screen shots of the day and have some
background information of the measurement right on the plot.

Since "modern" scopes can save directly to floppy disk, there is only
one way to store additional info: using a nice file name.
Does someone know, if there is a feature on modern scopes (TDS 6xx, 7xx)
to display ASCII text on the CRT?

Best,
Simon


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

Yahoo! Groups Links





User On-Screen Text

MailGate <mail_gate@...>
 

Dear group,

some (old?) Tek scopes allow the user to display ASCII - Text on the CRT.
This is nice, if you review your screen shots of the day and have some
background information of the measurement right on the plot.

Since "modern" scopes can save directly to floppy disk, there is only
one way to store additional info: using a nice file name.
Does someone know, if there is a feature on modern scopes (TDS 6xx, 7xx)
to display ASCII text on the CRT?

Best,
Simon


Re: How to Upload File

Egge Siert <eggeja@...>
 

Hi to All,

Yes indeed. I also had to upload my 067-0995-99 File to TekScopArc.

Egge-Siert


Solved - thanks! Re: Parts wanted: 155-0012 Z Axis Logic Tek IC - any offers?

magnustoelle
 

Hi,

A generous supporter and long term member of this group has just offered me his great help on this. I just wanted to take the opportunity to express how grateful I am for your help! You know who you are...

Cheers,

Magnus


7D12

rensetel
 

Hello All,
Who can help me finding 2x MosFet  (151-1067-00) or a replacement, used in the 7D12
Thanks, Rens Tel 


Re: How to Upload File

 

Hmmm

Has the Add File function been disabled 'cos the area is too full?

Regards,
David Partridge

-----Original Message-----
From: TekScopes@... [mailto:TekScopes@...] On Behalf Of danadak
Sent: 04 July 2011 23:58
To: TekScopes@...
Subject: [TekScopes] How to Upload File

I do not see any link that would permit me to upload a file to file area ? Help says such a link exists, but I cannot find it on page.

Regards, Dana.



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

Yahoo! Groups Links


Re: Problem calibration TEK 495P

hh <ciulandro@...>
 

Thanks,

i've made the test that you seggest and semm that the attenuator works.
I can allign manually the level of the 495 with the front trimmer using the RF generator as reference.
But the autocalibration routine always fail.
If i give 0dBm the routine start and appear a square wave.The dispaly says to use the AMPL trimmer for made the square wawe as a straight line but i can't reach the straigth line.

--- In TekScopes@..., Bob Koller <testtech@...> wrote:

The first thing I would check is the input attenuator. If you input, say, 0dbm from your generator, what is the on screen amplitude display? Is it close to the top of the screen with the input atten knob at 0db? Next, reduce the sig gen output in 10db steps and verify the steps with the 495 input atten knob. One of the first things to suspect is a damaged input attenuator, and /or damaged mixer. Of course, many other things can cause this, but these are suseptable to external input overload.

--- On Sun, 7/3/11, hh <ciulandro@...> wrote:

From: hh <ciulandro@...>
Subject: [TekScopes] Problem calibration TEK 495P
To: TekScopes@...
Date: Sunday, July 3, 2011, 2:19 AM
















 









Hello,



i've this problem on my Tek 495P.

When i start the calibration routine,with the internal generator 100Hhz -20 dB,the routine fails because the processor says taht there is any signal calibrator is present.

I've checked the output signal at 100Mhz -20 Db and is ok.



So i've connected to rf input an external RF generator at 100MHZ and the test start only when i give a signal @ 100Mhz 0(zero) dB.

Seem to be a loss of gain.

What can i verify in the instruments for repair this loss of gain?



Thanks for Any help.



MAX


Re: Lipstick On A Pig

d.seiter@...
 

The really funny thing is that the picture is apparently their stock photo.  Couldn't they find a better one?  Or maybe they have more 7A26s and this is the best one?

Dave



From: larrys@...
To: TekScopes@...
Sent: Monday, July 4, 2011 8:12:29 PM
Subject: Re: [TekScopes] Lipstick On A Pig

 

Hmmm...the person looking for 4XX horiz pos knobs could find the
one for the fine pos pot on that trigger source switch. lot of
$$ for a knob, though.

Jerry Massengale <jmassen418a@...> wrote:
>
>
> Hi,
>
> The is hope still in Connecticut. Check out 250849643172.
>
> jerry


Re: Lipstick On A Pig

teamlarryohio
 

Hmmm...the person looking for 4XX horiz pos knobs could find the
one for the fine pos pot on that trigger source switch. lot of
$$ for a knob, though.

Jerry Massengale <jmassen418a@...> wrote:



Hi,

The is hope still in Connecticut. Check out 250849643172.

jerry


Re: Lipstick On A Pig

Robert Simpson
 

Yea, 'GND' on channel 2 probably works great.
Bob


--- On Mon, 7/4/11, Jerry Massengale wrote:

From: Jerry Massengale
Subject: [TekScopes] Lipstick On A Pig
To: tekscopes@...
Date: Monday, July 4, 2011, 6:41 PM

 

Hi,
 
The is hope still in Connecticut. Check out 250849643172.
 
jerry


Lipstick On A Pig

Jerry Massengale <jmassen418a@...>
 


Hi,
 
The is hope still in Connecticut. Check out 250849643172.
 
jerry


Re: Tektronix 2215 problem

Greg Bowne <gbowne1@...>
 

As for the The TAS250: 
 
Here's a download from Tektronix for the 2215 manual. 
 
 
You're looking for document #070-4735-00.
 
If that doesn't work try this:
 
 
Try working on the Switchmode Power Inductor which might be loose on the 2213/2215's.  I've heard it to cause an audible whine.
 
Greg


From: Gordon Hale
To: TekScopes@...
Sent: Mon, July 4, 2011 12:34:44 PM
Subject: Re: [TekScopes] Tektronix 2215 problem

 

You wouldn't happen to know anything about the Tek TAS250 would you. I bought mine from ebay and it does not have the digital readouts available.  Thanks

Gordon Hale
Grand Prairie, Texas
Endeavor to Persevere


-----Original Message-----
From: Chris Moore
To: TekScopes@...
Sent: Mon, Jul 4, 2011 7:54 am
Subject: Re: [TekScopes] Tektronix 2215 problem

 
Daniel,
 
I have limited experience with troubleshooting, too. But from what I've seen so far, the service manual for tek scopes are very informative. They give you a heads up as to where to start troubleshooting and what to look for. They also help you source most parts in the unit by telling you what each part is and where it is located in the unit.
 
Chris

--- On Sun, 7/3/11, Daniel <timon4life@...> wrote:

From: Daniel <timon4life@...>
Subject: [TekScopes] Tektronix 2215 problem
To: TekScopes@...
Date: Sunday, July 3, 2011, 11:53 PM

 
I recently bought this 'scope from ebay and I got a good deal on it because it doesn't work. there seems to be some problem with the PSU it just makes a high pitched whine and I get no trace on the screen. I posted a video on youtube so you can see for yourselves what it's doing. what I want to know is what I should check for, where I can get replacement parts, or, where I can send this to get it fixed. I know intermediate electronics but i'm not great at troubleshooting. I'm more into repairing tube radios. that's kind of the reason I bough the scope. anyway hope someone can help me!

http://www.youtube.com/watch?v=GFPTLrw9enk


How to Upload File

danadak <danaaknight@...>
 

I do not see any link that would permit me to upload a file
to file area ? Help says such a link exists, but I cannot find
it on page.

Regards, Dana.


2465B quirks

Kurt Bosmans <bosmanskurt@...>
 

Hi All,

I recently obtained a 2465B oscilloscope from ebay. I have no prior experience with this type of scope so I hope someone can help me out with a couple of questions. I noticed some peculiarities and was wondering if they are normal or indicative of some fault.

The first peculiarity I noticed is that when I switch to faster sweep speeds the start of trace seems to creep to the right. In the fastest sweep speed I have to put the horizontal control almost all the way to one side to have the trace start at the left edge of the screen. The faster the sweep speed the more the trace shifts to the right.

The second peculiarity has to do with the vertical sensitivity and frequency response. I built a simple 100MHz square wave generator as described in Linear Tech application note 98 by the late Jim Wiliams (figure 8). The output of this generator is fed into the input of the scope set to 50 ohms. The generated signal is about 200mV peak to peak. When I view the signal in the 100mV/div setting it looks exactly like what I expected: a more or less decent square wave with a little "overshoot" at the starting edge due to the limited bandwidth of the scope. However when I then switch to the 50mV/div scale the shape of the wave changes drastically. The top and bottom of the wave now show a pronounced 500MHz (5th harmonic) oscillation. What could be the reason for this? I read that the bandwidth of the scope is limited to 350MHz for the highest sensitivity setting (2mV/div), but I can't find anything that would apply to the 100mV/div-> 50mV/div transition.

The third thing I noticed is that the trace becomes markedly more "fuzzy" when you switch on the times ten magnification. Comparing the same sweep speed as obtained with and without the magnification it seems there is some kind of jitter present on the triggering when the magnification is engaged. In effect the up and down going flanks of the square wave become much wider. Is this an artifact of the times ten magnification?

Best regards,
Kurt

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