Date   

Tektronix SA 2782

Vik Danchuk
 

Hi !
can you watch the video and tell us your opinion about it
https://groups.io/g/TekScopes/files/tek%202782.mp4

thanks in advance
Vik


Tek 1503C TDR

warren.stirling@...
 

Hi all,

Does anyone, by faint chance, have a replacement lcd assembly for a 1503C TDR?


Re: 465 Scope Question

Bill
 

I assumed as much since all the other voltages in the low voltage power supply are spot on. While in there I will replace all of them. Was on my list anyway.

This scope is in really nice cosmetic and physical condition so I decided to get it going again even though I don't need it. This old equipment deserves our respect in my opinion. I will also learn quite a bit along the way!!

Thanks for the reply!!

Bill


Re: I built a TM500 mainframe tester, and updated the design. Someone might find this useful? GROUNDING ISSUE

Shaun M
 

Mac,

Thanks for posting this. I encountered exactly the problem you described and I had just started to troubleshoot it: I thought perhaps I had a bridged solder connection somewhere. Problem solved!

Shaun Merrigan


Re: 465 Scope Question

Dave Hills
 

Bill,
C1562 most likely has failed. If it has you should see a large AC ripple voltage across it.
VR1522 is functional. If it were not, ALL the regulated voltages would be off, as they all
are referenced to it.

Dave


Started out with no -8vdc. Replaced the bridge rectifier now I have -6.5vdc.
The power transistor Q1566 checks out as OK. Lifter C1569 but that didn't
help. The voltages on Q1566 are ok except the Collector voltage is a little
over =3vdc when it should be +5vdc. I'm going on the assumption that
something downstream is dragging down the -8vdc but is not a dead short.

Sound reasonable?

All the other Low Voltage power supplies are dead on in voltage.
Bill


Re: I built a TM500 mainframe tester, and updated the design. Someone might find this useful? GROUNDING ISSUE

Mac Perkins
 

Many thanks to Jared for his elegant design, I've been meaning to build one of these for some time.

After building the test unit and starting to test frames, I encountered a problem in the beta test positions of the switch.

The BNC connector is not isolated and is wired across the meter HI and LO posts, The toothed lug washer shorts the LO terminal to ground through the front sub-panel and the frame of the module.

Fortunately the 5K1 resistors seemed to limit the current available and prevent damage.

My solution was to connect the BNC ground lug to the GND terminal with a short wire rather than the pad provided which connects to the meter LO terminal . It is still a good idea to disconnect the oscilloscope in the beta measuring positions as even the 1 meg scope input influences the reading significantly.

-Mac


Re: Unable to see some images in 75th anniversary consolidated pdf

Tom Lee
 

Hi Dave,

I don’t know if anyone has replied to you, but they’re referring to a pdf now available at vintagetek. It’s currently featured on their front page. You’ll enjoy reading it, I’m sure!

—Cheers,
Tom

Sent from my iThing, so please forgive typos and brevity.

On Apr 25, 2021, at 12:24 PM, Dave Voorhis <voorhis@gmail.com> wrote:

On 25 Apr 2021, at 19:40, Tommy <tommy@rausberg.se> wrote:

The subject line pretty much tells it: most images are there but some don't show on my computer (Howard's First Scope and World War Two, for example).
Anyone else seeing this or is it my computer ?

While they were presented one by one all were viewable but it would be nice to have the whole thing...
Where, and what, is this 75th anniversary consolidated PDF?

It wounds interesting, but I’ve never heard of it.






Re: Unable to see some images in 75th anniversary consolidated pdf

Lyle Bickley
 

Hi Tommy,

I suggest you download the PDF rather than viewing it "online". Various
browsers do different things with images, etc.

I've looked at the PDF with Acrobat and okular (on Linux) and all the pictures
are fine...

Cheers,
Lyle
--
On Sun, 25 Apr 2021 11:40:08 -0700
"Tommy" <tommy@rausberg.se> wrote:

The subject line pretty much tells it: most images are there but some don't
show on my computer (Howard's First Scope and World War Two, for example).
Anyone else seeing this or is it my computer ?

While they were presented one by one all were viewable but it would be nice
to have the whole thing...






--
73 NM6Y
Bickley Consulting West
https://bickleywest.com

"Black holes are where God is dividing by zero"


Re: Unable to see some images in 75th anniversary consolidated pdf

Tommy
 

Jus realised he pdf displays ok in Firefox, go figure...

Sorry for the wasted bandwidth.


Re: Unable to see some images in 75th anniversary consolidated pdf

Glydeck
 

Tommy,

Downloaded and tried the pdf on several readers and it seems ok. Maybe you’re using an older version of Acrobat?

George

On Apr 25, 2021, at 1:54 PM, Tommy <tommy@rausberg.se> wrote:

https://vintagetek.org/tek_75/





Re: 465 Scope Question

Mark Vincent
 

Bill,

Check the ac voltage across C1562. It sounds like your filter condenser is bad. If the cap is bad, replace it with 3300-4700mfd 25V UHE type. These are the best I have found for ESR and life. Filter condensers in these and 7603s seen to give problems and replacement is necessary.

Also check VR1522. I have never seen one of the 9V zeners be good. Yours is likely open. I know it may not make a difference in the output voltage. I change these in my units with BZX85B9V1.

Mark


Re: Unable to see some images in 75th anniversary consolidated pdf

Tommy
 


Re: Unable to see some images in 75th anniversary consolidated pdf

Dave Voorhis
 

On 25 Apr 2021, at 19:40, Tommy <tommy@rausberg.se> wrote:

The subject line pretty much tells it: most images are there but some don't show on my computer (Howard's First Scope and World War Two, for example).
Anyone else seeing this or is it my computer ?

While they were presented one by one all were viewable but it would be nice to have the whole thing...
Where, and what, is this 75th anniversary consolidated PDF?

It wounds interesting, but I’ve never heard of it.


465 Scope Question

Bill
 

Started out with no -8vdc. Replaced the bridge rectifier now I have -6.5vdc. The power transistor Q1566 checks out as OK. Lifter C1569 but that didn't help. The voltages on Q1566 are ok except the Collector voltage is a little over =3vdc when it should be +5vdc. I'm going on the assumption that something downstream is dragging down the -8vdc but is not a dead short.

Sound reasonable?

All the other Low Voltage power supplies are dead on in voltage.
Bill


Unable to see some images in 75th anniversary consolidated pdf

Tommy
 

The subject line pretty much tells it: most images are there but some don't show on my computer (Howard's First Scope and World War Two, for example).
Anyone else seeing this or is it my computer ?

While they were presented one by one all were viewable but it would be nice to have the whole thing...


Re: 7L12 spur at 210MHZ - Request for test results or suggestions?

Jean-Paul
 

correction at 210 MHz I can see -100 dBm, above noise, no spurs at all anywhere 0-1500 MHz

Jon


Re: Good storage solution for collection of 500-series plugins?

Roy Thistle
 

On Sat, Apr 24, 2021 at 12:30 PM, - wrote:


I store my plugins in one of the silver colored ziplock anti static bags
If one is going to do that, either displace the air with dry nitrogen gas... which I assume everyone has... or put in a new (or properly salvaged) desiccant bag.
Here in the colonies, the military always seems to put them in.
If you don't... unless you live in the Mojave Desert.. you might regret it.

--
Roy Thistle


Re: Corrosion Damage – TM500 Plugins

Keith
 

Not to rub salt in the wound, but by coincidence just yesterday I was inventorying some electronic parts I have. They are stored in OEM packaging dated 1965. They were stored the old fashioned way, taped up in crinkle paper wrap. They have never been opened since 1965, so I opened one up just to check it.
The part was perfect. Bright shiny contacts, no corrosion, no funk, no issues. That’s 56 years, and no issues.

Like you guys and gals, I remember when the various kinds of foams became available. They looked cool, seemed to provide better protection against physical shock, etc., so I used them for a while, until I opened up an anvil case that had been stored for several years, and found a mass of goo-coated equipment...ruined by the degrading foam.

I went back to paper to wrap parts, and keep them in snap lid plastic containers. Sometimes I toss in a bag of silica gel, because the containers do breathe a bit. Yes, I take the risk of the static danger from the paper. If I am really worried about it I spray the paper with fabric softener and let it dry in the sun. The fabric softener eliminates the static threat.

Sometimes the old way is the right way. Try paper. It works pretty good.


Re: 465M

Ananda
 

Thanks, Tom and Michael. I will give those a try.


Re: 465M

Mlynch001
 

The circuitry for the DC restorer circuit is likely shorted. The 465M DC restorer is build in along with the HV multiplier as a unit of U550.

--
Michael Lynch
Dardanelle, AR

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