Date   
Re: 465 dot only, no sweep

james_55@...
 

On Sat, Apr 4, 2020 at 08:44 PM, Bill wrote:


More than likely a capacitor has shorted. Probably a Tantalum.
Bill
Don't think so, as if it was shorted the voltage would be close to zero.

But thanks

Re: 465 dot only, no sweep

james_55@...
 

On Sat, Apr 4, 2020 at 04:12 PM, Tom Miller wrote:



My first guess would be check C1562, a 3000uF can capacitor on the main
board.
That was what I was testing in another thread, and it seemed ok.

Re: Tek 576 Curve Tracer HV Replacement Transformer

 

Hi Ernesto,

It is probably a waste of my time to reply to your rant. My conclusions, from reading your comments are:
1) You haven’t got a clue what it takes to run a successful business.
2) You only think of yourself.
3) You think everything should be available forever at a price acceptable to you.
I decided to reply because I hope to learn something I don’t know. You clearly have an issue with the way Tek runs its business; ergo there are companies that run their businesses at least as well, or better, than you were expecting from Tek. I expect you to name one or more of those companies to justify your rant. I, and the other members of TekScopes, will benefit from learning which companies you have dealt with that provide the customer service and support you came to expect from Tek. So please answer the following question so we all may know who you recommend for their support and service:
-----------
Name me a company that maintains an inventory of spare parts for anything they built 50 years ago. Be sure to include only the companies that provide this service for individuals who paid less than 5% of the original cost of the instrument and who will expect the spare part to likewise cost 5% of its original manufacturing cost.
-----------
When the HV Transformer on my favorite scope, a 7854, failed this was simply not an acceptable situation. Unlike you I didn't expect a company that once was known for its stellar support to carry a spare part 30 years later just for me. I didn't disparage the company for not designing this part so it could last past my death 50 years later. Instead I got off my butt and called the manufacturer of the part listed in the Tek manual. I gave them the part number and I asked for a quote. They contacted me a few days later to say they would be happy to make a batch of them for only $425 each with a minimum order of five. Their quote was not unreasonable. Should I have explained to them that although this 7854 cost $10,000 new I bought it on eBay for $400? Therefore the replacement transformer should only cost $400 / $10000 = 4% of its new price, or $425 * 4% = $17. Do I dare follow this up by saying I only want to pay for one? Would they still be in business 30 years after the scope was made if they sold their transformers on eBay for $17? If I had told them Ernesto expects them to make it for around $17 would they have taken his opinion into consideration or would they have shown me the door?

If you have an issue with Tek or the way they run their business there are other companies who make similar products, but I doubt they have the incredible support network we do from the vintageTEK Museum, TekWiki, TekScopes Forum, and Tek’s own Service Manuals. Keep us posted on what you find. If you find something better we will all be interested in hearing about it.

I, for one, know how extremely fortunate I am that there once was a company whose dedication to quality, exceptional engineering, and excellence in everything they did, resulted in instruments that still work as good as they did 40, 50, even 60 years after they were built. Their legacy lives on with the support we receive from the volunteers at the vintageTEK Museum, the incredible creation of Kurt Rosenfeld who gave us TekWiki, Michael Dunn who recognized the need 20 years ago for the TekScopes Forum, and the amazing Service Manuals that Tek produced to support every instrument they made. I would be remiss if I didn’t include eBay. It would not be possible for us to own these incredible instruments without the marketplace they created for used Tek equipment 25 years ago.

Dennis Tillman W7pF

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of Ernesto
Sent: Saturday, April 04, 2020 7:21 AM
To: TekScopes@groups.io
Subject: Re: [TekScopes] Tek 576 Curve Tracer HV Replacement Transformer

<SNIP>
(Rant-mode-on) If mlynch001 can be a source of replacement transformers, WHY CANNOT Tektronix have been the one?
Don't they feel any responsibility for their products? A part they manufactured with an OBVIOUS defect that can totally disable one of their expensive instruments?
If Michael could find a manufacturer, could they not have taken an infinitesimal part of their huge development and manufacturing facility to make these transformers?
And they didn't need to lose money. If not free, they could have delivered this parts at cost. For all their old scopes that have this HV transformer problem.
As my esteem for the old Tektronix instruments increases, my regard for Tektronix Inc with its over a billion dollars revenue keeps falling.



--
Dennis Tillman W7PF
TekScopes Moderator

Re: Ringing on 2235 100 volt supply

John G
 

Barry,
BTDT. I missed plugging in one of the ribbon cables.
John

On Sat, Apr 4, 2020 at 03:00 PM, <barry.ballenger@...> wrote:


Same here worked fine then quit when I put it back in to test. Have you
worked on any attenuator boards. Looking for what might be wrong on mine.

Re: Capacitor testing

Roy Morgan
 

Long and expert experience with Collins amateur equipment tells us to limit the reforming current to FIVE MILLAMPS.

Take your time. Monitor cap voltage and reforming current. Be patient.

I have a Heath variable bench supply - DC variable from about 0 to 300 volts or so, I use a 10k or 5K, 5 or 10 watt resistor in series. The current meter on the supply lets me keep reforming current low, and a separate voltmeter shows me the caps progress.

Do not follow the procedure given in the MIL-HANDBOOK on reforming electrolytics. There is real danger of disaster doing that (Parallel many caps, reform them with a light bulb series with a DC supply, limiting current to the total for all caps.)

Roy


On Apr 4, 2020, at 5:14 AM, james_55@... wrote:

Hi and thanks for the sugestion.

Any recommendation as to the resistor value?

1k 100k?

Roy Morgan
K1LKY since 1958
k1lky68@...

Re: Ringing on 2235 100 volt supply

barry.ballenger@...
 

Same here worked fine then quit when I put it back in to test. Have you
worked on any attenuator boards. Looking for what might be wrong on mine.

On Sat, Apr 4, 2020 at 2:47 PM John G <mnjgfl@...> wrote:

I removed it when I re-capped everything.

On Sat, Apr 4, 2020 at 01:55 PM, <barry.ballenger@...> wrote:


John did you have the attenuators board.out to repair. My B channel quit
working and believe it may be the B attenuator board.


Re: OT Seeking Sencore CA55 Capacitor Analyzer CA55

Roy Morgan
 

From a discussion three years ago on Antique Radio Forums:

https://antiqueradios.com/forums/viewtopic.php?f=8&t=318097


Post subject: Re: Sencore CA55 capacitor testerPosted: Mar Sun 19, 2017 4:10 am
Member

Joined: Sep Tue 30, 2014 6:08 am
Posts: 5333
Location: Norfolk, VA
Micro Precision Calibration has the manual, and apparently will make a copy of theirs for a fee. http://www.microprecision.com

Back a few years ago, I was asked about the CA55 ( I have a working LC102 and two dead LC53s) and found them on the web. Feedback was that the guys who needed the manual for the CA55 were able to purchase a manual copy from them. They have a ton of locations, so patience in dealing with them was the key. I have no affiliation with them at all.

_________________
Brian
"Capacitor Cosmetologist since 1979"
USN Retired 1984-2006 (Avionics/Cal)


On Apr 4, 2020, at 3:23 PM, Yiu On Tony C via groups.io <tonycheung_hk=yahoo.com@groups.io> wrote:

Dear Members :

I am sorry , it is OT topic, I am being seek the manual/ schematic/ calibration information etc....

CA55 of Sencore is a capacitor analyzer, I cannot find related service information on web site .
Roy Morgan
K1LKY since 1958
k1lky68@...

Re: 465 dot only, no sweep

Abc Xyz
 

What would cause Both Traces to be Shifted Right on a 465B?

On Sat, Apr 4, 2020, 12:44 PM Bill via groups.io <ko4nrbs=
yahoo.com@groups.io> wrote:

More than likely a capacitor has shorted. Probably a Tantalum.
Bill



Re: Ringing on 2235 100 volt supply

John G
 

I removed it when I re-capped everything.

On Sat, Apr 4, 2020 at 01:55 PM, <barry.ballenger@...> wrote:


John did you have the attenuators board.out to repair. My B channel quit
working and believe it may be the B attenuator board.

Re: 465 dot only, no sweep

Bill
 

Re: 465 dot only, no sweep

Bill
 

More than likely a capacitor has shorted. Probably a Tantalum.
Bill

OT Seeking Sencore CA55 Capacitor Analyzer CA55

 

Dear Members :

I am sorry , it is OT topic, I am being seek the manual/ schematic/ calibration information etc....

CA55 of Sencore is a capacitor analyzer, I cannot find related service information on web site .

Regard
Tony Cheung
APR 5 2020

TDS7054 not booting

Tom B
 

Hello All,

I have an old TDS7054 (windows 98) that hangs while booting. The problem seems to be that it is looking for a Banyan vines network.  Could someone tell me how to keep it from trying to boot using files from the network?  Booting in safe mode I found the registry entry for the file, but I don't just want to delete the entry.  So, given that it is windows 98, what do I do to fix the problem?

Tom Bryan

Re: 2445A slow

Steve
 

On Sat, Apr 4, 2020 at 03:01 PM, Steve wrote:



--
Kind Regards,

steve


Meant to type Vishay not visual!

Re: 2445A slow

Steve
 

Thanks for that lesson in capacitance I'm in no way being snobby when I say this but that was excellent information that I haven't been privy too until you told me that in your message concerning upping the value of capacitance, so thank you VERY much for the education. I keep like I said Nichicon UPW series low esr high ripple on hand to re cap most all of my jobs so I'm going to assume that those will work by your message. I have some visual and Wima film style caps as well as some ceramic discs caps. I hate to ask a redundant question but would the film type caps be suitable for the safety caps or should I go with something different? I plan on recapping the LV supply today. I'm not familiar with the other part of the scope that needs recapped as well matter of fact I'm not quite sure what to look for ( Anode supply board) I have most all of the values that you listed for the LV supply and I purchase all my parts from mouser. I have some 1uf Wima film caps if that would work for the one bipolar cap. I'm not sure I have the other film caps in the specified voltage values but I'll look. Also, I did as you said about not pressing any channel buttons in xy mode but all I get is an angled line with no comb from transistor specs. I'm positively sure it's operator error as I get a good readout on my digital scope it's just real grainy and hard to read hence me purchasing this scope, primarily to use my curve tracers with.......

--
Kind Regards,

steve

Re: DAS9100 does anyone still remember it

Brian
 

Hi Dan , I will re-read that section of the manual . When I read it before I got the impression that all the mnemonics command did was read the data from the tape in the drive and acqmem again involved the tape drive . There was no mention of the form the data would take or needed to be . I will set the system up and try via GPIB to see what happens - if I have enough time tomorrow . I will let you know what I find .
Thank you for taking the time to help .
Brian

On Saturday, 4 April 2020, 19:39:19 BST, Dan G <dgajanovic@...> wrote:

Hi Brian,

I believe that the information you are looking for is contained in section 12 (GPIB Programming)
of the DAS 9100 Series Operator's Manual. A PDF is available in bitsavers.org's Test Equipment Archive,
as well as our TekWiki (w140.com).

In particular, I think you will be interested in the ACQMEM command to transfer the acquisition
memory to your computer, as well as the MNEMONICS command to transfer the Define Mnemonics
menu setup to and from the DAS mainframe.

As far as I know, DAS 9100 uses the RS-232 port as a poor man's GPIB interface, so these commands
should work over RS-232 as well, though I have not tested this myself.

According to the Tektronix 1985 catalog, Tek used to offer a suite of UNIX software tools (91DVV),
with source code (!), for generating test patterns and transferring data to and from the DAS.

Incidentally, I still have a working VAX system, so if someone has these old tapes gathering dust,
I would love to get a chance to preserve and archive them.


dan

Re: Ringing on 2235 100 volt supply

barry.ballenger@...
 

John did you have the attenuators board.out to repair. My B channel quit
working and believe it may be the B attenuator board.

On Sat, Apr 4, 2020 at 1:37 PM John G <mnjgfl@...> wrote:

The 6 mm is just a bit short. I cut a 4-4 screw about 7 mm long and it
worked perfect. Maybe the holes are slightly stripped.
Thanks for affirming it should be 6 mm.
John

On Sat, Apr 4, 2020 at 11:49 AM, <barry.ballenger@...> wrote:


john where is a pix of the screw from my scope, it is 6 mm long

On Sat, Apr 4, 2020 at 8:48 AM John G <mnjgfl@...> wrote:

Thanks Barry, I have the screws somewhere in the scope, obviously not
in
the right place. The length would be helpful.
Thanks
John





Re: 2782 electrical schematics

evdsp39
 

Hi again,
No, the CRT tube is good  as I see all the information on the screen but completly unfocused.I suppose that the D/A are not working or perhaps the circuits arround this D/A.Because the current confinement it will unfortunately be bad for later...
Etienne.

Le mardi 31 mars 2020 à 04:50:13 UTC+1, Ernesto <ebordon@...> a écrit :

Hi evdsp39,

The manual in tekwiki has also plenty of block diagrams but no circuit diagrams.  (has Tektronix decided that circuit diagrams are obsolete??)

Did you get any response from the poster who has the circuit diagram at the other site you consulted,

https://forum.tek.com/viewtopic.php?t=135234&__cf_chl_jschl_tk__=dc56ddefd230acd93f9df188b708ab0c7f1bdfa0-1585625507-0-AUli2D36HpqZDRXn-ihg6gHacpOqzFNHDEmQrYFNPgH_kJ1htEG_qitoaRsN4qbrGkD5fIWZJ1M6hMcEmlFPd0e_fuHtwnO6JRYC7tWT1wsyLjOQb2qvBAe7RyDbn_K2OaWiz5NRRkNsF-6gZEaB_pAS__bQWkaY2o_40rHanBMI_pNg1bW9owRlllUguzCobQeejkSWAYd1ozrG91kGPa3l5LXoPR-CPDZtysPYAiCqinX-KAYDvIbupKa9fx6D6cEc5JdnIgOR6v1MeJX247DzL2FhBntGoq2MD5G8r_IJXiClcJIZ0BgvzFQg15tl90N_vf8sr6ExdFwBanxERAg5ONkr-4uTXrNdWZkG512H ?

When you say that focus, astigmatism and intensity are not working,  does this mean that the tube seems to be dead?
If you find no circuit diagrams,  can you go into the instrument and measure the voltages at the CRT, probably wrong or missing, and improvise a traditional high voltage supply for this CRT that at least lets you see something on its screen?

Re: DAS9100 does anyone still remember it

Dan G
 

Hi Brian,

I believe that the information you are looking for is contained in section 12 (GPIB Programming)
of the DAS 9100 Series Operator's Manual. A PDF is available in bitsavers.org's Test Equipment Archive,
as well as our TekWiki (w140.com).

In particular, I think you will be interested in the ACQMEM command to transfer the acquisition
memory to your computer, as well as the MNEMONICS command to transfer the Define Mnemonics
menu setup to and from the DAS mainframe.

As far as I know, DAS 9100 uses the RS-232 port as a poor man's GPIB interface, so these commands
should work over RS-232 as well, though I have not tested this myself.

According to the Tektronix 1985 catalog, Tek used to offer a suite of UNIX software tools (91DVV),
with source code (!), for generating test patterns and transferring data to and from the DAS.

Incidentally, I still have a working VAX system, so if someone has these old tapes gathering dust,
I would love to get a chance to preserve and archive them.


dan

Re: Ringing on 2235 100 volt supply

John G
 

The 6 mm is just a bit short. I cut a 4-4 screw about 7 mm long and it worked perfect. Maybe the holes are slightly stripped.
Thanks for affirming it should be 6 mm.
John

On Sat, Apr 4, 2020 at 11:49 AM, <barry.ballenger@...> wrote:


john where is a pix of the screw from my scope, it is 6 mm long

On Sat, Apr 4, 2020 at 8:48 AM John G <mnjgfl@...> wrote:

Thanks Barry, I have the screws somewhere in the scope, obviously not in
the right place. The length would be helpful.
Thanks
John