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2465B error code

Chris
 

Hello members,I have not been on in quit awhile and have recently run across an error in a 2456B scope. It pops up after the start up cyle and curious what it means? What shows up is CT test 84 fail OC . I have not used this scope at all but got it to play with awhile ago and it has been sitting. I am only a hobbiest so please bear with me. Thanks ahead, Chris

Re: Tek 465B Magic Soot

CARL MESROBIAN
 

I have the Artek manual - it's searchable, too :)

I will check c4006 at some point - thanks!

Re: Tek 465B Magic Soot

 

The 465B is a fine analog scope.

Ok, first, the black soot is just that. It is attracted by the high voltage field around the red cable. It is just mostly carbon exhaust.

The fuse is in the unregulated +15 supply and _IF_ you are very lucky, it is just a shorted tantalum capacitor C4006. The capacitor is under the HV shield in the corner of the board and is a 47uF-35 volt dipped tant. You can just use a good quality 105°C aluminum electrolytic

The second most likely thing that blows that fuse is the HV multiplier module. They run around $50+ and it is a task to replace. The procedure is covered in the service manual.

Do you have the service manual?


Retards,
Tom

----- Original Message -----
From: cmguitar50@... [TekScopes]
To: TekScopes@...
Sent: Thursday, November 09, 2017 6:43 PM
Subject: [TekScopes] Tek 465B Magic Soot



I bought a 465B as-is, etc. and thought I could get it up and running and discovered fuse 4508 was blown. I put a 1A in it's place and that blew also.



I decided to move this beast off my bench and while doing so discovered some magic soot on the inside of the case and on a CRT connection ? (red wire). also. Is this thing worth fixing? I have another scope that works, so theres no urgency to it.




https://groups.yahoo.com/neo/groups/TekScopes/photos/albums/1633260205 https://groups.yahoo.com/neo/groups/TekScopes/photos/albums/1633260205

Re: tek 2712 freezes during startup

ti8jlh
 

El 08/11/2017 a las 05:50 p.m., @rodd [TekScopes] escribió:

Hi, I have replaced the batteries but the SA freezes at the same point.
I was hoping that I would find a loose connection or similar issue
since it is a long way from US to Brazil, and it was "in working
condition" when I bought it (with photos).
Unfortunately that was not the case.
I wonder if the problem is related to the front panel since the last
line of the error screen says "press W to cont; Z to abort" but I have
tried every key and nothing happens.
Is it possible to know if the problem is really a freeze during boot
or a defective front panel?
Any other ideas?
The link to the error screen and the lighted leds of the front panel
is attached below.
https://groups.yahoo.com/neo/groups/TekScopes/photos/photostream/lightbox/191654049?orderBy=mtime&sortOrder=desc&photoFilter=ALL#zax/2075059146
https://groups.yahoo.com/neo/groups/TekScopes/photos/photostream/lightbox/191654049?orderBy=mtime&sortOrder=desc&photoFilter=ALL#zax/2075059146



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

Hello Roger, I forgot to ask you if you looked at the 100 Mhz TXCO as
Jochen wrote?
I will try to do that tomorrow.
Joachim


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

Tek 2711 freezes

ti8jlh
 

Hello RogerAs you can see my SA shows a similar or the same problem.I will look at the 100 Mhz TCXO as Jochen posted.I hope this will be the solution.I tried many times to repair it without success. RegardsJoachim  TI8JLH

Re: Replacing BR-2/3A Batteries

chipbee40
 

The battery in question is the Panasonic BR2/3A Lithium poly-carbonmonoflouride with a nominal voltage of 3V. I don't change these out unless they are below 3V.They last almost shelf life which is many years. I'm assuming as the OP states these are in 22xx scopes they are in the options for the 2230, or in the 2232 where they do not maintain calibration constants merely saved waveforms and soft data. These are expensive and costly to ship (UPS/Fedex ground only) so I would seriously consider if its worthwhile changing them unless necessary (they don't leak). Not sure about HP equipment, haven't come across them in there. Personally on the 2230/2232 I'd prefer to put a couple of quality AA's in with a note to change them out in a year.. Fluke did this on the PM339x combiscopes.


---In TekScopes@..., <davidwhess@...> wrote :

The common lithium chemistries for this application all have a very
flat discharge curve:

<http://www.tadiranbat.com/compare-lithium-cells.html http://www.tadiranbat.com/compare-lithium-cells.html>

Lithium Thionyl Chloride 3.6 volts: (Tektronix used these)
<https://www.eetimes.com/author.asp?section_id=36&doc_id=1322276 https://www.eetimes.com/author.asp?section_id=36&doc_id=1322276>

Lithium Sulphur Dioxide 3.0 volts: (My HP meter has one of these)
<https://www.eetimes.com/author.asp?section_id=36&doc_id=1323439 https://www.eetimes.com/author.asp?section_id=36&doc_id=1323439>

3.4 volts means that it is a lithium thionyl chloride cell. With such
a small load, the voltage should be more like 3.6 volts so it has
almost reached the end of its life.

Common lithium batteries are lithium manganese dioxide with a terminal
voltage of 3.0 volts. Any of these three types of lithium cells may
be used. I have been using Tadiran Lithium Thionyl Chloride 2/3AA
cells with wire leads because they have the best performance/price:

<https://www.mouser.com/ProductDetail/Tadiran-Batteries/TL2155-P/?qs=sGAEpiMZZMtLoaml0iHoQ%2f%2fIdmmZouk5jrbtVEs2eJA%3d https://www.mouser.com/ProductDetail/Tadiran-Batteries/TL2155-P/?qs=sGAEpiMZZMtLoaml0iHoQ%2f%2fIdmmZouk5jrbtVEs2eJA%3d>

Tek 465B Magic Soot

CARL MESROBIAN
 

I bought a 465B as-is, etc. and thought I could get it up and running and discovered fuse 4508 was blown. I put a 1A in it's place and that blew also.



I decided to move this beast off my bench and while doing so discovered some magic soot on the inside of the case and on a CRT connection ? (red wire). also. Is this thing worth fixing? I have another scope that works, so theres no urgency to it.




https://groups.yahoo.com/neo/groups/TekScopes/photos/albums/1633260205 https://groups.yahoo.com/neo/groups/TekScopes/photos/albums/1633260205

Re: A 2465 teaser...

Chuck Harris
 

A hook is a trace that goes from vertical to horizontal
with a little curve between. If you could see the whole
thing, it would look like a shark's tooth, or a lazy
saw tooth pulse.

With display off, it looks like this:

(_____________________________________________CH1

(_____________________________________________CH2

_____________________________________________CH3
_____________________________________________CH4

When you turn display on it looks like:


(__(____(____(______(________(_______(((___(__CH1

(_(__(_____(________(___(_____(_((_____(_(((__CH2

_____________________________________________CH3
_____________________________________________CH4

The "(" sections are actually a sharp rise with
a slower fall, and look like random grass. They
appear only on CH1 and CH2, not at all on CH3 and CH4.

The "(" sections after the trigger are at least
0.75 div high, and unaffected by vertical input
condition, or attenuator setting. The initial pulse
hook, is undoubtedly just one of the "herd"... only
it appears with or without the display being turned
on.

I haven't tried replacing the CH1 and CH2 preamp
yet. It would surprise me to find that both failed
in exactly the same way at the exactly the same time.

[Note that CH1 and CH2 are otherwise performing normally,
and in calibration, and that the "(" stuff does not
appear in the CH2 output connector on the back panel.
I would think that would rule out the preamps.]

It would seem more likely to me that it would be
a bad bypass cap on a filter section that feeds both
CH1 and CH2 in parallel. But the power looks pretty
clean, and nothing larger than 1 or 2 mv.

-Chuck Harris

hahi@... [TekScopes] wrote:

I am puzzled. Anyone have any ideas?
Not sure exactly what you mean by hooks ...

This may not be the same but I have seen a few scopes with noise
on the trace(s) looking like about one minor div of digital noise
randomly across the trace(s). All fixed by replacing the preamp(s).

/HÃ¥kan





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Posted by: hahi@...
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Yahoo Groups Links



Re: A 2465 teaser...

 

I am puzzled. Anyone have any ideas?
Not sure exactly what you mean by hooks ...

This may not be the same but I have seen a few scopes with noise
on the trace(s) looking like about one minor div of digital noise
randomly across the trace(s). All fixed by replacing the preamp(s).

/HÃ¥kan

Re: Tek 547 A Sweep display during retrace

Dave Wise
 

I hope someone can try it out. I'm out of town right now.

Dave Wise

On Nov 9, 2017, at 2:05 PM, David @DWH<mailto:@DWH> [TekScopes] <TekScopes@...<mailto:TekScopes@...>> wrote:

The 2N5401 might still be fast enough. I suggested it and the BC556
because they are relatively common. The KSA992 is the best of the
commonly available and inexpensive options that I found.

I was not able to find any detailed specifications on the original
2N2207 to make a better comparison between it and modern parts. The
low voltage output capacitance is a start but not sufficient.

On Thu, 9 Nov 2017 19:48:38 +0000, you wrote:

I think KSA992 is a better bet with 3pf max.

Dave Wise

On Nov 9, 2017, at 11:15 AM, David Wise david_wise@...<mailto:david_wise@...><mailto:david_wise@...> [TekScopes] <TekScopes@...<mailto:TekScopes@...><mailto:TekScopes@...>> wrote:

2N5401 is 6pf vs 2.3 . It will be much slower in this application.


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Posted by: David <@DWH<mailto:@DWH>>
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Yahoo Groups Links

Re: Tek 547 A Sweep display during retrace

 

The 2N5401 might still be fast enough. I suggested it and the BC556
because they are relatively common. The KSA992 is the best of the
commonly available and inexpensive options that I found.

I was not able to find any detailed specifications on the original
2N2207 to make a better comparison between it and modern parts. The
low voltage output capacitance is a start but not sufficient.

On Thu, 9 Nov 2017 19:48:38 +0000, you wrote:

I think KSA992 is a better bet with 3pf max.

Dave Wise

On Nov 9, 2017, at 11:15 AM, David Wise david_wise@...<mailto:david_wise@...> [TekScopes] <TekScopes@...<mailto:TekScopes@...>> wrote:

2N5401 is 6pf vs 2.3 . It will be much slower in this application.

A 2465 teaser...

Chuck Harris
 

Hi Gang,

I have a 2465 that spends most of its time on my shelf
as a "should fix this soon" hanger queen.

The problem is thus far, I can't figure out what's wrong
with it.

If you are showing simple ground traces, CH1 and CH2 both
have an identical 0.2 x 0.2 division upward facing "hook" on
the left end of the trace. It moves with the vertical position
control, but is completely unaffected by settings of the
attenuator, and does *not* appear on the CH2 BNC on the rear
panel of the scope... nor would I expect it to, preamps no
nothing of the sweep.

CH3 and CH4 show no sign of the hook. They are perfect.

If you turn on the readout, the hook remains, but there are
3/4 division whispy little hook traces dancing randomly along
the CH1 or CH2 trace. Lots of them. Nothing on the CH3 or CH4
traces. Horizontal rate affects how they are displayed, in the
way you would expect.

My first thought was something that CH1 and CH2 have in common,
the CH3 and CH4 do not.

CH1 and CH2 share some filtered power supply voltages, and have
some power supply voltages that CH3/CH4 do not.

CH1 and CH2 share a couple of opamps in the trigger pickoff
circuitry.

CH1 and CH2 pass through the channel switch through different
channels than CH3 and CH4, and the display readout.

The power supply has been recapped, and tested in another 2465,
that doesn't show the problem.

The Channel switch has been swapped with a 2465 that doesn't
show the problem. All the circuits connections and components
around the channel switch were tested for continuity, shorts,
value...

The Display Sequencer has been swapped with a 2465 that doesn't
show the problem... not that I thought it would make any difference.

The Z axis controller has been swapped with a 2465 that doesn't
show the problem... not that I thought it would make any difference.

All electrolytics on the A1 board have been replaced. What can I
say, the scope is gorgeous, I thought someone might appreciate it.

The noise doesn't appear on the power supplies, or the power rails
at the various hybrids.

All of the published waveforms in the vertical section match the
test points (except for a couple which are known to be wrong in
the manual).

All of the resistors and pots around the channel switch have been
tested. I even pulled U475 and replaced it (because I got a
strange junction measurement that turned out to be ok.

I am puzzled. Anyone have any ideas?

-Chuck Harris

Re: Tek 547 A Sweep display during retrace

Dave Wise
 

I think KSA992 is a better bet with 3pf max.

Dave Wise

On Nov 9, 2017, at 11:15 AM, David Wise david_wise@...<mailto:david_wise@...> [TekScopes] <TekScopes@...<mailto:TekScopes@...>> wrote:

2N5401 is 6pf vs 2.3 . It will be much slower in this application.







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Posted by: David Wise <David_Wise@...<mailto:David_Wise@...>>
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Yahoo Groups Links

Re: P6015A HV probe

 

It would not be that dangerous but it would destroy the probe.

Follow the refilling procedure described in the manual but make sure
to add too much butane and then bleed it off as described to release
any remaining air. Just like with freon 114, some remaining liquid
butane should be visible. Any remaining gas mixture will then be far
outside the explosive limits.

On Thu, 09 Nov 2017 19:26:55 +0000, you wrote:

With butane you have to be sure, to load the probe with NO air and by
this with NO oxygen. Else you may have a inflamable mixture, which could
build a real bomb, if arcing happens.

Re: P6015A HV probe

 

Sure it makes a difference but it also makes a difference in
dielectric constant between liquid and gaseous form. I deliberately
used the numbers for dielectric strength in gaseous form.

I gather that freon 114 was deliberately used as a gaseous dielectric
by others for the same reason Tektronix used it; boiling below room
temperature allows it to positively displace air in the device and its
low vapor pressure allows simple low pressure construction and the
maintenance of a liquid reserve to maintain positive pressure. Butane
has all of those advantages as well but of course it is flammable but
I do not really consider that a serious problem in this application
where the volume is so low.

The slightly higher vapor pressure of butane over freon 114 should
somewhat make up for its lower dielectric strength if that is a
problem. In any event, it is cheap, readily available, and an
improvement over using nothing. I have been reluctant to purchase one
of the older probes but this changes my mind.

On Thu, 9 Nov 2017 19:09:26 +0000, you wrote:

Does it make a difference that it's in gaseous form?

On Nov 9, 2017, at 11:06 AM, David @DWH<mailto:@DWH> [TekScopes] <TekScopes@...<mailto:TekScopes@...>> wrote:

I never considered butane either. My only concern would be its
dielectric strength. Let's see ...

Freon 114 is 1,2-Dichlorotetrafluoroethane with a dielectric strength
of 2.52 compared to nitrogen. Butane has a dielectric strength of 1.5
or 1.7 compared to nitrogen depending on information source.

The breakdown voltage is further increased over nitrogen because the
freon 114 and butane are used at higher than atmospheric pressure.

Re: P6015A HV probe

Herbert
 

With butane you have to be sure, to load the probe with NO air and by
this with NO oxygen. Else you may have a inflamable mixture, which could
build a real bomb, if arcing happens.



Am 09.11.2017 19:09, schrieb David Wise david_wise@... [TekScopes]:



Does it make a difference that it's in gaseous form?

On Nov 9, 2017, at 11:06 AM, David
@DWH<mailto:@DWH> [TekScopes]
<TekScopes@...<mailto:TekScopes@...>> wrote:

I never considered butane either. My only concern would be its
dielectric strength. Let's see ...

Freon 114 is 1,2-Dichlorotetrafluoroethane with a dielectric strength
of 2.52 compared to nitrogen. Butane has a dielectric strength of 1.5
or 1.7 compared to nitrogen depending on information source.

The breakdown voltage is further increased over nitrogen because the
freon 114 and butane are used at higher than atmospheric pressure.

On Thu, 9 Nov 2017 13:34:43 -0000, you wrote:

You know, I have looked long and hard at various replacements for FC114
in recent years, and I had
not considered butane.

But looking at the NIST site for FC114 you get 1.83 atmospheres at 20C,
and with butane you get 2
atmospheres. So similar enough not to lose too much sleep over.

And the dielectric constant of butane gas at 2atm is, not surprisingly
very close to unity 1.0056

I haven't found any data for the gas phase dielectric of FC114, but it
will be likewise very close
to unity.

So, very cautiously, it would appear that butane is a possible
replacement for unobtainium FC114.

Craig

-----Original Message-----
From: TekScopes@...<mailto:TekScopes@...>
[mailto:TekScopes@...]
Sent: 09 November 2017 10:45
To: TekScopes@...<mailto:TekScopes@...>
Subject: RE: [TekScopes] P6015A HV probe

Hi, you can use butane.

http://4hv.org/e107_plugins/forum/forum_viewtopic.php?100570

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Posted by: David <@DWH<mailto:@DWH>>
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Yahoo Groups Links



Re: Tek 547 A Sweep display during retrace

Dave Wise
 

2N5401 is 6pf vs 2.3 . It will be much slower in this application.

Re: P6015A HV probe

Dave Wise
 

Does it make a difference that it's in gaseous form?

On Nov 9, 2017, at 11:06 AM, David @DWH<mailto:@DWH> [TekScopes] <TekScopes@...<mailto:TekScopes@...>> wrote:

I never considered butane either. My only concern would be its
dielectric strength. Let's see ...

Freon 114 is 1,2-Dichlorotetrafluoroethane with a dielectric strength
of 2.52 compared to nitrogen. Butane has a dielectric strength of 1.5
or 1.7 compared to nitrogen depending on information source.

The breakdown voltage is further increased over nitrogen because the
freon 114 and butane are used at higher than atmospheric pressure.

On Thu, 9 Nov 2017 13:34:43 -0000, you wrote:

You know, I have looked long and hard at various replacements for FC114 in recent years, and I had
not considered butane.

But looking at the NIST site for FC114 you get 1.83 atmospheres at 20C, and with butane you get 2
atmospheres. So similar enough not to lose too much sleep over.

And the dielectric constant of butane gas at 2atm is, not surprisingly very close to unity 1.0056

I haven't found any data for the gas phase dielectric of FC114, but it will be likewise very close
to unity.

So, very cautiously, it would appear that butane is a possible replacement for unobtainium FC114.

Craig

-----Original Message-----
From: TekScopes@...<mailto:TekScopes@...> [mailto:TekScopes@...]
Sent: 09 November 2017 10:45
To: TekScopes@...<mailto:TekScopes@...>
Subject: RE: [TekScopes] P6015A HV probe

Hi, you can use butane.

http://4hv.org/e107_plugins/forum/forum_viewtopic.php?100570


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Posted by: David <@DWH<mailto:@DWH>>
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Yahoo Groups Links

Re: Replacing BR-2/3A Batteries

 

I had detailed notes from when I looked into this a couple years ago.

On Thu, 9 Nov 2017 10:40:13 -0600, you wrote:

Thanks to Mitch and David Hess for answering my battery question, with David as usual exhibiting an in-depth knowledge of almost everything. Jake

Re: P6015A HV probe

 

I never considered butane either. My only concern would be its
dielectric strength. Let's see ...

Freon 114 is 1,2-Dichlorotetrafluoroethane with a dielectric strength
of 2.52 compared to nitrogen. Butane has a dielectric strength of 1.5
or 1.7 compared to nitrogen depending on information source.

The breakdown voltage is further increased over nitrogen because the
freon 114 and butane are used at higher than atmospheric pressure.

On Thu, 9 Nov 2017 13:34:43 -0000, you wrote:

You know, I have looked long and hard at various replacements for FC114 in recent years, and I had
not considered butane.

But looking at the NIST site for FC114 you get 1.83 atmospheres at 20C, and with butane you get 2
atmospheres. So similar enough not to lose too much sleep over.

And the dielectric constant of butane gas at 2atm is, not surprisingly very close to unity 1.0056

I haven't found any data for the gas phase dielectric of FC114, but it will be likewise very close
to unity.

So, very cautiously, it would appear that butane is a possible replacement for unobtainium FC114.

Craig

-----Original Message-----
From: TekScopes@... [mailto:TekScopes@...]
Sent: 09 November 2017 10:45
To: TekScopes@...
Subject: RE: [TekScopes] P6015A HV probe

Hi, you can use butane.

http://4hv.org/e107_plugins/forum/forum_viewtopic.php?100570