horz output FETs in 2245?
I sent this the other day to the other TekScopes list but thought I would
try here too for more ideas.
I was given a 2245 recently which of course doesn't work too well.
Investigation reveals that Q805 and Q806, in the horizontal right plate
output stage, are cold to the touch.
The service manual, section 6.2 (page 6-19) says,
The MOSFET output transistors (Q801 and Q802 left plate-- Q805 and
Q806 right plate) run hot. If either side is cold, it is defective.
So, that's me and now I need to find a couple of these VDMOS FETs, which
seem to have become quite rare.
They are Tek P/N,
151-1211 VN1316N2 N-Channel VDMOS FET, 160V, 250mA, 40 ohm
151-1212 VP0116N2 P-Channel VDMOS FET, 160V, 250mA, 25 ohm
Has anyone solved this problem with a modern replacement pair? and have
suggested substitutes? These are in TO-39 package which adds additional
challenge but I suppose TO-220 or equiv could be made to fit. Of course,
the real thing would be great too if there is a source.
Thanks for any leads!
Chris
--
Chris Elmquist
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Tektronix and HP Catalogues Available
I am still cleaning up and ran across a 1980 Tektronix Catalog, a 1981 Tektronix Catalog, a 1980 HP Catalog, and a 1981 HP Catalog.? All are hard covers.? The are free if you pay the shipping costs although I would gladly accept and appreciate donations!
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Re: Tek 492 SA PSU removaal
Back in the day...? While I was working at Tek UK (Maidenhead.)
The first 492 that came into the UK was unpacked by Sales for a
demo, and instantly blown up!
Those early units were 115V input only...? While the UK was 240V
mains!
So (no pressure of course) with no manual, figured out how to get
inside, remove the PSU, stripped it down, found the dead parts,
and traced the input circuit, converted it from full wave doubler,
to full wave rectifier (one trace cut, from memory.)
Replaced the Diodes, Fuse, and power FET'setc in the primary
switching side, and gently wound it up on a Variac.? Some strange
noises (no load) but no fire or brimstone either.? Checked some
secondary voltages, that seemed to be "safe", so powered down, and
re-assembled it all.
It powered up fine* and worked without issues.
(*No such thing as PAT testing then, if the ELCB(RCD) on the
bench didn't trip, it was good to go!)
Shortly after, it was in the back of a car on it's way to a major
UK customer for demo/evaluation, who eventually bought several of
them...
(A "Portable" microwave SA?? Only if you were built like Arnie,
and even then you'd end up with one arm longer than the other!??
Good instruments for what they were capable of in a "portable"
form factor back then.)
Did I get any kudos for that "emergency repair"??? Of course
not.?? The first of many such events working for a string US based
companies in the UK, when I bailed out sales or similar...? I
never learnt!
The 492P appeared a few days before before I left.
I still sometimes come across a 492 (as well as other Tek kit of
that era, I was there for 3 years) still sporting stickers,
showing my initials...? Never gets me any discount though!
73.
Dave. "DJB"
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Re: Tek 492 SA PSU removaal
James thanks for your RIFA warning
They tend to fail on 240v mains, we are 120v here.
This 492 was unused for 20 years and in great shape
Thus I leave it for now as it's working fine, but should rework the PS sometime
Looking for a front cover and printed service manual as I am very bad with PDFs
Have an absolutely fantastic day
Jon
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Re: Tek 492 SA PSU removaal
Change the Rifas as they WILL blow.
? I've worked on a few of these PSU's and they are very reliable, however many/most are 40+ years old now and need some TLC.
?Do you have BOTH manuals??
If not I'll post the 2nd one (with the PSU details) into the archives.
?Good luck?
?
James
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Re: Tektronix TDS754D - failing acquisition module tests
To answer some possible questions, I've reflowed the U200 solder joints, to eliminate the possibility there's one or more "cold" ones.?
On Sat, Mar 22, 2025 at 5:39?PM Radu Dicher < vondicher@...> wrote: Jared and all, I finally managed to make this work with my GPIB solution.? The error seems to be:
"SAT MAR 22 17:19:35 2025 ?ERROR: diagnostic test failure, digDataFormatDiag, ?ERROR!!BYTE mode, in demux 200 ,i= 4 memBaseAdr 0x738000a= ?data = fffffa00, expectedData[i] = aa00"
I wonder if anyone can shed some light into this error, and whether it seems to point to anything useful for troubleshooting. This is the only error standing, apparently.?
On Mon, Mar 10, 2025 at 5:42?PM Radu Bogdan Dicher via <vondicher= [email protected]> wrote: That makes perfect sense, thank you, Jared. I assume, once I recover my adapter (just realized it's currently?on loan), I need to run the commands via Python (the only way I know).? Radu.?
The scope doesn't care what GPIB adapter you use, if it works on other gear, it'll work on the scope.
?
You only need the specific National Instruments GPIB card for running the Tektronix calibration software.
?
All other GPIB functions can be done with any working GPIB adapter.
?
?
?
Jared.
|
Re: Tektronix TDS754D - failing acquisition module tests
Jared and all, I finally managed to make this work with my GPIB solution.? The error seems to be:
"SAT MAR 22 17:19:35 2025 ?ERROR: diagnostic test failure, digDataFormatDiag, ?ERROR!!BYTE mode, in demux 200 ,i= 4 memBaseAdr 0x738000a= ?data = fffffa00, expectedData[i] = aa00"
I wonder if anyone can shed some light into this error, and whether it seems to point to anything useful for troubleshooting. This is the only error standing, apparently.?
On Mon, Mar 10, 2025 at 5:42?PM Radu Bogdan Dicher via <vondicher= [email protected]> wrote: That makes perfect sense, thank you, Jared. I assume, once I recover my adapter (just realized it's currently?on loan), I need to run the commands via Python (the only way I know).? Radu.?
The scope doesn't care what GPIB adapter you use, if it works on other gear, it'll work on the scope.
?
You only need the specific National Instruments GPIB card for running the Tektronix calibration software.
?
All other GPIB functions can be done with any working GPIB adapter.
?
?
?
Jared.
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Re: [TekScopes] 7934 Service Manual
Bob,
Yes, thank you. I see that I concluded that it doesn't have sections 8 and 9 because I was looking at the end of the PDF, which are the Change Information pages. I do see the duplicate pages.
Without a copy of the original manual (or an original manual itself) I can't tell what else might be incorrect with the online copies. Since many of the pages of the online copies are partial pages, I'd have to compare the pages in the online PDFs to an original manual. Perhaps someone out there could do that, but since the 7934 is pretty rare, I doubt that there is anyone who is paying attention to this thread who will do that.
I have sent pp. 31, 6-22 and 6-23 to Mark, the OP. That will have to suffice, for now. I may upload my revised PDF that contains those three missing pages. I can scan my original that is a later revision, but that will take a lot of time due to the fold-out pages.
DaveD
KC0WJN
toggle quoted message
Show quoted text
On 3/22/2025 9:16 AM, mst3krules via groups.io wrote: The copy I look at came from this link:
Part No. 070-5880-00
MANUAL Product Group No. 42
First Printing May 1986
It has what I assume is section 8, which isn't numbered, then section 9 followed by a section of Manual Change Information then the duplicate pages.
Bob
--
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|
Re: [TekScopes] 7934 Service Manual
I don't see any duplicate pages in the TekWiki copy of the 7934 manual.
Also, the May 1986 PDF ends with section 7. My copy (Aug 1987) has sections 8 and 9.
I'm a bit confused. It would be helpful if someone out there has an original, printed copy of the May 1987 (unrevised) copy of the manual.
DaveD
KC0WJN
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Show quoted text
On 3/22/2025 7:24 AM, mst3krules via groups.io wrote: Pages 459 - 467
Bob
--
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Re: [TekScopes] 7934 Service Manual
Dang. I forgot to write that I also added the missing page 3-1 to the May 1986 revision.
DaveD
KC0WJN
toggle quoted message
Show quoted text
On 3/22/2025 5:56 AM, Dave Daniel via groups.io wrote: All,
Ok, I've unbound my 7934 manual and I started scanning the missing pages.
It turns out that my manual copy is Revision May 1986, but *Revised Aug 1987*.
Per Bob's email below:
Pages x, 9-12 and 9-24 are the last pages of their respective sections and are blank pages in my manual with no page numbers (but the facing pages are consistent).
My section 7 ("Replaceable Electrical Parts") is much different than the section 7 in the May 1986 revision. Updating the May 1986 revision with my section 7 would make the former revision inconsistent, so I do not plan to do that. My manual has no page 7-61; my section 7 ends at page 7-54. However, I would guess that page 7-61 in the May 1986 revision is the last page of section 7 and therefore blank and not numbered.
I have added pages 6-22 and 6-23 to my local copy of the May 1986 revision that is on the TekWiki site. I think that that omission is the only true error in the TekWiki manual revision. I will update the copy on TekWiki, hopefully later today (I am on EDT). In the meantime, I can send a copy of pages 6-22 and 6-23 to anyone that can't wait for me to update the copy on TekWiki. Please PM me in that case. kc0wjn at gmail dot com.
Comments and questions welcome; those should probably be handled privately at this point so as to not clutter up the list.
DaveD
KC0WJN
On 3/21/2025 7:04 PM, Dave Daniel via groups.io wrote:
Thank you.
Sigh. I guess I'll have to unbind my copy and add those to the copy on
TekWiki.
DaveD
KC0WJN
On Fri, Mar 21, 2025 at 17:56 mst3krules via groups.io <mst3krules=
[email protected]> wrote:
Looking through the manual, of the pages with numbers, the following are
missing:
X, 3-1, 6-22, 6-23, 7-61, 9-12, 9-24
Bob
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|
Re: [TekScopes] 7934 Service Manual
All,
Ok, I've unbound my 7934 manual and I started scanning the missing pages.
It turns out that my manual copy is Revision May 1986, but *Revised Aug 1987*.
Per Bob's email below:
Pages x, 9-12 and 9-24 are the last pages of their respective sections and are blank pages in my manual with no page numbers (but the facing pages are consistent).
My section 7 ("Replaceable Electrical Parts") is much different than the section 7 in the May 1986 revision. Updating the May 1986 revision with my section 7 would make the former revision inconsistent, so I do not plan to do that. My manual has no page 7-61; my section 7 ends at page 7-54. However, I would guess that page 7-61 in the May 1986 revision is the last page of section 7 and therefore blank and not numbered.
I have added pages 6-22 and 6-23 to my local copy of the May 1986 revision that is on the TekWiki site. I think that that omission is the only true error in the TekWiki manual revision. I will update the copy on TekWiki, hopefully later today (I am on EDT). In the meantime, I can send a copy of pages 6-22 and 6-23 to anyone that can't wait for me to update the copy on TekWiki. Please PM me in that case. kc0wjn at gmail dot com.
Comments and questions welcome; those should probably be handled privately at this point so as to not clutter up the list.
DaveD
KC0WJN
toggle quoted message
Show quoted text
On 3/21/2025 7:04 PM, Dave Daniel via groups.io wrote: Thank you.
Sigh. I guess I'll have to unbind my copy and add those to the copy on
TekWiki.
DaveD
KC0WJN
On Fri, Mar 21, 2025 at 17:56 mst3krules via groups.io <mst3krules=
[email protected]> wrote:
Looking through the manual, of the pages with numbers, the following are
missing:
X, 3-1, 6-22, 6-23, 7-61, 9-12, 9-24
Bob
--
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|
Re: [TekScopes] 7934 Service Manual
It occurs to me that, if I am going to unbind my 7934 manual (re-binding is a pain) to scan pages 6-22 and 6-23 in order to update the copy on TekWiki, it would be useful to know if there are any other pages missing from the online copy. This would require someone to go through the online manual page-by-page to verify that those two pages are the only ones missing. I don't have time to do that right now. If someone is willing to do that, please let me know ASAP.
I should probably update the PDF of the manual on the TekWiki site. That'll
take a bit longer.
DaveD
KC0WJN
On Fri, Mar 21, 2025 at 16:08 Dave Daniel via <kc0wjn=
[email protected]> wrote:
> I have been skimming this thread, since I have a 7934, but not really
> paying close attention to it.
>
> I have an original 7934 manual from Tektronix, dated May 1986. It does have
> pages 6-22 and 6-23. I can scan and upload them or send them privately.
> It'll take me a day or two to do that.
>
> DaveD
> KC0WJN
>
>
> On Fri, Mar 21, 2025 at 15:51 Bill via <wpgold3637=
> [email protected]> wrote:
>
> > After looking at 3 totally different scans of the same printing of the
> > 7934 manual I don't believe that pages 6-22 and 6-23 were in any manuals
> > from the first printing.? My three scans show file sizes of:
> > 1.? ? 112,361 KB? ? Title? "7934 Oscilloscope (1986) WW.pdf"? 464 pages
> > long
> > 2.? ? ?210,637 KB? ?Title "7934.pdf"? (SECURED)
> > 470 pages long
> > 3.? ? ? ?72,903 KB? ?Title "Tektronix-7934-service,user-ID2530.pdf"? ?501
> > pages long
> > #3 in the "schematics" section, the pages have been scanned 1/2 page at a
> > time for those pages that were probably "B"size in the original manual.
> In
> > some cases they were scanned in 1/3 page at a time.
> > #2 in the "schematics" section the pages are scanned the whole page at a
> > time.
> > #1 same as #2.
> > There are other differences in the "schematics" sections with sizes of
> the
> > pages, when I go through the pages at the same magnification settings of
> > the Adobe Reader.? #2 has some protection applied and is "SECURED".? I
> > can't use the "Snapshot Tool" from the "Tools" menu.? In one scan I can
> see
> > the holes for the spiral binding which the others don't have on the same
> > page.? There are other differences on the placement of some texts.? But
> > that could be from the scanning process.? I don't know.
> > My conclusion and best guess is that, believe it or not, Tektronix did
> NOT
> > print those missing pages in the first printing dated "May 1986".? GASP!
> > There are pages of "CHANGE INFORMATION" in the back of each scan.? One
> > shows signs of being stapled while others don't show this.
> > However is anyone can find those missing pages please scan and post them.
> > Bill
> >
> >
> >
> >
> >
> >
>
>
>
>
>
>
|
Jon, the newer RG223/U cables have a lot more flexibility.
--
Jeffeelcr
|
Re: 2467B Sweep test waveforms
Hello again"
BEWARE that CAL requires
Exact TEK test equipment
Caled test scope and probes
Experience with CAL proceedures, VERY steep learing curve for first timere
DANGER: HOR K IC U800 is EASY TO BLOW UP and costly to replace.
The screws MUST NOT be touched or moved , at -5V NOT GRD
If scope works fine, good accuracy H, V, trig OK and display of CRT good, DONT MESS IT UP.
See very long thereads at TEKSCOPES2 here and EEVBLOG Tek 2465B teardown.
Just my decades of experience on about 15 of these.
Have a great day
Jon
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Re: 2467B Sweep test waveforms
Hello: All photos CANNOT be added to a message in this group. Kindly visit /g/TekScopes2/photosCreate a new album title, descr Then add the LINK to the new album here Jon
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Re: looking for LEMO power supply jack (ERA.OS.304.CLL)
Hi.
LEMO still make them:
(Part number obtained from the tekwiki page, and searched for
with Google.)
Plus, it seems Mouser and DigiKey list them.
Not low cost, but you'd get the exact correct part, and no need
to rob someone else¡¯s spares unit.
I know there are alternatives (second source, and all that) but
in a past job where they were also used, we experienced some minor
incompatibility issue, usually resulting in them being strangely
difficult to un-mate.
73.
Dave 'KBV?? Ex Tek UK during the Harpenden & Maidenhead
years.
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Hi David Nice to hear that I will try to download Thanks for info.? Regards On Fri, Mar 14, 2025, 10:12 AM David C. Partridge via <david.partridge= [email protected]> wrote:
You can DL the 2465B manual direct from and that is a very high-quality PDF. ? D. ? ? Dear Jon
Thanks for your response.
I had downloaded the manual from the site manualslib couple of days before and downloaded the manual from the site you described. It seems little difficult to follow when it comes to schematic and assembly drawing section. I understand the manuals are downloaded free of cost and cannot hope for better as originals.
Regards
Saroj ? On Thu, Mar 13, 2025, 8:47 PM Froggie the Gremlin via <jonpaul=[email protected]> wrote: Hello again dear Sir,
See W140/ tekwiki for all Tektronix manuals in PDF
Also the Vintage Tektronix Museum
Manual you need is service, for the? the serial number and exact model, options
Artek has printed reproductions.? Cost - 40-80$
Ebay may have originals, but seldom and costly.
We DL the PDF,and print sections as,needed
Follow the troubleshooting flow charts.
Enjoy
Jon
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Re: looking for LEMO power supply jack (ERA.OS.304.CLL)
Check the Japanese connectors from Hirose, they made cross version of the Lemo.
Jon
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Re: looking for LEMO power supply jack (ERA.OS.304.CLL)
The TekWiki site page at
one will find a list of Tektronix units that use those Lemo connectors.
My intended point was that a scrap or "spares" 1101 or 1101a could also provide the needed connectors.
Chuck
On Fri, Mar 14, 2025 at 6:12 PM, John Gord via Bill,
You don't need the separate supply; you can just add the power jacks to the 2465B.? They were available as an option (option 22, I think), and the connections for them are already present on the Regulator Board as J201 and J202.? The outlines of the holes are visible on the back panel, and the connectors and their internal cables are shown as item 33 on the Chassis mechanical drawing.
You just need the connectors an some wiring.
--John
?
On Fri, Mar 14, 2025 at 04:33 PM, bill K7WXW wrote:
Wondering if anyone who has a "spares" 465, 475, or 485 would be willing to pull a couple of the LEMO power jacks from the back (the four pin jackused to power Tek probes that use +/-15VDC) for me.? I want to build a stand alone power supply so I can use some of my power-required probes on my 2465B, which aren't equipped with them. ?
email is K7WXWatqrpdxdotnet or message me here.
Thanks!
Bill
|
Re: looking for LEMO power supply jack (ERA.OS.304.CLL)
My intended point was that a scrap or "spares" 1101 or 1101a could also provide the needed connectors. Chuck
On Fri, Mar 14, 2025 at 6:12 PM, John Gord via groups.io <johngord@...> wrote: Bill,
You don't need the separate supply; you can just add the power jacks to the 2465B.? They were available as an option (option 22, I think), and the connections for them are already present on the Regulator Board as J201 and J202.? The outlines of the holes are visible on the back panel, and the connectors and their internal cables are shown as item 33 on the Chassis mechanical drawing.
You just need the connectors an some wiring.
--John
?
On Fri, Mar 14, 2025 at 04:33 PM, bill K7WXW wrote:
Wondering if anyone who has a "spares" 465, 475, or 485 would be willing to pull a couple of the LEMO power jacks from the back (the four pin jackused to power Tek probes that use +/-15VDC) for me. ?I want to build a stand alone power supply so I can use some of my power-required probes on my 2465B, which aren't equipped with them. ?
email is K7WXWatqrpdxdotnet or message me here.
Thanks!
Bill
|
Froggie the Gremlin
James55