Keyboard Shortcuts
ctrl + shift + ? :
Show all keyboard shortcuts
ctrl + g :
Navigate to a group
ctrl + shift + f :
Find
ctrl + / :
Quick actions
esc to dismiss
Likes
- TekScopes
- Messages
Search
|
Re: TEK 321A
Make sure you read the topic all the way to the end, I updated old posts three or more times as better recipes were discovered.
Dave Wise ________________________________ From: TekScopes@groups.io <TekScopes@groups.io> on behalf of Sigur?ur ?sgeirsson via groups.io <siggi@...> Sent: Thursday, January 9, 2025 7:51 AM To: TekScopes@groups.io <TekScopes@groups.io> Subject: Re: [TekScopes] TEK 321A Hey Jason, I don't know anything about Ge transistor replacement. I did, however, find this thread (/g/TekScopes/topic/7640286#msg35340) apparently written by people who've worked on the 321A and replaced some of the 2N2207s with modern-ish Si transistors. Maybe this will help? Good luck, Siggi On Thu, Jan 9, 2025 at 10:12?AM jason neumann-grable via groups.io <magrepha1@...> wrote: Hi: I'm a new subscriber and somewhat of a computer-illiterate, so I hope |
|
Re: TEK 321A
Hey Jason,
I don't know anything about Ge transistor replacement. I did, however, find this thread (/g/TekScopes/topic/7640286#msg35340) apparently written by people who've worked on the 321A and replaced some of the 2N2207s with modern-ish Si transistors. Maybe this will help? Good luck, Siggi On Thu, Jan 9, 2025 at 10:12?AM jason neumann-grable via groups.io <magrepha1@...> wrote: Hi: I'm a new subscriber and somewhat of a computer-illiterate, so I hope |
|
Re: OT: Artek Manuals "Distro"?
Ron,
I second that - great to hear this is all legit and then quite a bit more. Thank you for clarifying. Radu. On Thu, Jan 9, 2025 at 6:13?AM Wayne via groups.io <WAYNECL= AOL.COM@groups.io> wrote: Ron, |
|
TEK 321A
magrepha1@gmail.com
Hi: I'm a new subscriber and somewhat of a computer-illiterate, so I hope
this is the right place to ask questions. I have a Tek 321A scope that I am very anxious to get working. However, it has the "legendary" 2N2207 transistors (lots of 'em) that grow crystals inside and short themselves out. I recently acquired (at considerable cost) 10 more of the little jewels - - every *$&%^# one of them was bad ! Does anyone out there know of a substitute device or a fix that would enable me to get this scope working ? I worked at Tek when the 321 was first introduced and this scope has considerable sentimental value. Thanks for whatever help y'all can give !? Jason Neumann-Grable KF7JEI |
|
2N2207 TRANSISTORS
magrepha1@gmail.com
I have a Tek 321A that is loaded with these transistors. They have a reputation for failure, due to growing crystals inside that short them out. I recently acquired 10 more and every one of the #&$%# things was bad.
Is there a "fix" for this problem that uses another device? I'd really like to get this little jewel going again. It has great sentimental value to me, as I worked at Tek when the 321 was first introduced. Any help would be greatly appreciated. Jason Neumann-Grable |
|
Re: Tristar processor
This group doesn't permit attachments. Please write an off-list email to
toggle quoted message
Show quoted text
me. I'll the pdf to you WBR чт, 9 янв. 2025?г. в 17:36, Night Walker <walkerru@...>: Hello Gianni, |
|
Re: OT: Artek Manuals "Distro"?
Ron,
Thank you for posting, and for your willingness to help to carry on Dave's legacy through this assistance to Linda. The value of Dave's dedication to those of us who need these manuals is unsurpassed, so far as I know, and it is wonderful that his work can continue even after his untimely and unfortunate passing. Many will find Artek products on ebay that perhaps would not know of their service otherwise. Thanks again, Wayne |
|
Re: 7633 Fast Level Center adjustment
Fast Level Center is mentioned in sections 11 and 13 of the Calibration section of my manual, pages 5-64 onwards (probably from TekWiki but it is so long ago I can't remember!). You have to get past a lot of other calibration stages to get this far!
My 7633 has a seriously worn out CRT so I was never able to proceed beyond checking the various pulse sequences were correct and the voltages were at least in the correct ball park. I also have a 7623A which is in much better shape and was able to complete the (very lengthy) storage calibration and confirm that I could still get the advertised writing speed. Regards, Roger |
|
7633 Fast Level Center adjustment
Hi,
I could not find any explanation about how to set this semi-fixed front panel control on the 7633. Manuals say: ? FAST LEVEL CENTER adjustment is provided to separately adjust the fast mesh voltage for the desired tracking of the STORAGE LEVEL, on the two meshes. ? FAST LEVEL CENTER-Adjusts the voltage level of the FAST target relative to the viewing target and, therefore, the tracking of the STORAGE LEVEL for the two targets. But it is not clear to me how must I adjust it, besides some empirical attempts. Does someone know more? |
|
Re: OT: Artek Manuals "Distro"?
All,
I am the licensed reseller / distributor for Artek Manuals on eBay as "Artek Manual Distro" through an agreement with the owner / operator of Artek Manuals. "Distro", short for distributor. Their website continues as before Dave's passing. eBay, for some unexplained reason, delisted the Artek eBay listings. I have been reposting selected items. The agreement includes compensation back to Artek Manuals. So all is on the up-and-up. I appreciate the concern of the group and will let Linda know. Dave put in an exceptional level of effort to provide high quality scans, especially HP/Agilent with permission from Agilent. His passing was quite unexpected and a sad loss. regards, Ron |
|
Re: 7904 SMPS woes
Please disregard. I see where Jon mentioned the "hidden" ones.
toggle quoted message
Show quoted text
Barry - N4BUQ Did you include the tantalums on the backplane that are somewhat hidden behind |
|
Re: 7904 SMPS woes
Did you include the tantalums on the backplane that are somewhat hidden behind one of the interface boards (C60, C62, C64, C66)?
toggle quoted message
Show quoted text
Barry - N4BUQ Yep, as I mentioned that is all out of the machine and I pulled said tants on |
|
7000 series plug-in contact rating?
Does anyone know if there's an official current-carry rating for the 7K main interface connectors. That is, maximum continuous DC through the connector's spring contact into the plug-in's board edge contact, per contact. Only the carry is needed, not the make or break ratings.
I think virtually every commercially made connector type has these and voltage specs too, but since the 7K ones are Tek-made, it may not be so clear. I'm hoping for some internal document or experimenting or experience or other, kind of like the empirically derived 7K power supply and plug-in load characteristics. Anything should help. I believe a first estimate may be somewhere around 4 amps, since (I think) any one-wide plug-in may have only a single contact for each supply, yet be able to dump an entire supply well over 4A peak for a SMPS supply trying to launch but ticking in a 7XX4 frame, or continuously at the foldback limit in a linear 7XX3. Like say, when there's a shorted Ta cap in a plug-in. Ed |
|
Re: 7904 SMPS woes
Yep, as I mentioned that is all out of the machine and I pulled said tants on the backplane - no love. Which were your bd ones?
I kinda been down these roads... looking for next road :) - to recap (pun intended) - - 15 bad -- to quickly check if a particular board (vert, horiz, cal, Z) I pulled jumpers to each one by one. no love - pulled main interface board which as Jon said has tants all over the place for -15V - I measured as many as I could find - no love at all. I'm tryign to finish the isolation of SMPS itself VERSUS a shorted element in the mainframe. I guess Ill try to load down the PSU and see if standing by itslef its OK or not. TY for the advice - it seems like I am following the manuals correctly as well as having read the internet accuratelty for what to do. Oran- the manuals say to use a variac to decrease input AC voltage to troubleshoot the SMPS. Thanks for the help! |
|
Re: 7904 SMPS woes
Minimum 7904 supply currents from H?kan's earlier message:
toggle quoted message
Show quoted text
-50 V: 0.08 A -15 V: 0.8 A +5 V: 0.4 A +15 V: 1 A +50 V: 0.2 A + 130 V: 0.036 A +5 Lights: 0.3 A Don't forget to check the caps after the rectifiers but before the regulators. You can go with a DVM across each cap and check for a short, some tantalums on the supply look like rectangular dipped mica capacitors but they are tantalum caps. One of them was bad on my 7904. Supply resistances measure higher than the troubleshooting manual, likely a difference in DVM used as you also guessed. Ozan On Wed, Jan 8, 2025 at 01:44 AM, William wrote:
|
|
Re: OT: Artek Manuals "Distro"?
Em 08/01/2025 14:07, Radu Bogdan Dicher via groups.io escreveu:
That's right, and it's hard to not make the case that the use of the nameWell, I do a lot of scanning myself () and I may add my 2 cents: Firstly, there is no ownership in scanning. The manuals are sole property of their owners/creators and what we do is gray area. I do that for preservation, I want to have rare manuals avaiable so they are preserved and not lost forever. Also rare books and other documents. But most of the material is copyrighted and Artek or me or whoever scans it isn't the owner of the material, nor has the RIGHTS (mark this word) to sell it. BUT and this is a big BUT, we who scan and preserve materials, use not to sell others' work. Dave had a legitimate "function" - He scanned good quality manuals and you paid for his service of having it scanned. But it gives him no "rights" nor anyone else. As a preserver myself, I prefer to do that for free. All my manuals are free and no one is alowed to ask anything for them, nor put its mark, stamp or web site address on it. But to each, its own. Bottom line: Don't buy schematic CDs. They are all on the web. And if they aren't, put them on. If you are going to pay for it, donate for people who scans for free, or buy from Artek and other sellers who DO LEGIT SCAN WORK instead of leechers who get others' work and just sell it. 73 de PU2SEX Alexandre |
|
Re: OT: Artek Manuals "Distro"?
That's right, and it's hard to not make the case that the use of the name
is at least a bit iffy, because of that. It's entirely possible the place does a lot of repairs where they needed Artek SMs and now they have them, and they're no longer needed. Not sure how to think through ownership of, essentially, software, but I guess selling those CDs is within their rights as they bought them. Or maybe not quite? Not a specialist, so all this is shooting from the hip, and not meant to be disrespectful in any way. But no question they are legit Artek CDs, of which I have several. Radu. On Wed, Jan 8, 2025, 8:52 AM Sigur?ur ?sgeirsson via groups.io <siggi= sort.is@groups.io> wrote: On Tue, Jan 7, 2025 at 10:42?PM Dave Daniel via groups.io <kc0wjn= |
Jean-Paul
Alexandre Souza
to navigate to use esc to dismiss