Tektronix 465 Scope


Michael W. Lynch
 

On Sun, Apr 18, 2021 at 05:23 PM, Raymond Domp Frank wrote:




No “B”.
That makes it a Guernsey-produced instrument and a rather late one at that.
Non-US (i.e. non-B) numbers cannot be cross-referenced to applicable serial
numbers in the SM’s, which are all US (Beaverton-) related.
One of the most frustrating things when working on a Non-Beaverton Instrument. I ran into this myself when working on my Guernsey built 465 and a pair of Heerenveen built 468's.

--
Michael Lynch
Dardanelle, AR


Bill
 

Thank you!! Yes it was a typo.
Bill


Tom Lee
 

In cases where it is difficult to trace a signal from its point of origin forward, it may be easier to trace backward from some point downstream. Most likely you are looking for a shorted tantalum, and those stand out. A few quick ohmmeter measurements, and you’ll identify which are connected across the problem supply.

Just a thought, should obtaining a proper manual prove difficult.

— Tom

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

On Apr 18, 2021, at 4:49 PM, Bill via groups.io <ko4nrbs=yahoo.com@groups.io> wrote:

Page 174 in the 465 Service manual is the schematic of the scope's power supply.

On page 168 just underneath R1460 (Potentiometer) you can see R1463, CR1465, VR1414 and R1441. On my scope there are only two resistors in that spot and no diode.

Will just have to go hand over hand until I find the bad component on the -8vdc rail. My old 453 has an excellent manual but the manual is for it's serial number.

Bill





Dave Peterson
 

Bill,

I presume you are looking at the early service manual, as "Fig 7-17 P/O A9 Interface circuit board" matches your description.

I think you have a typo: you meant VR1441?

Your description more closely matches the "SN B250000 & UP" service manual, "CRT Circuit" and "Fig 8-14 A9 - Interface circuit board".

I think Raymond is right, you have a Gurnsey (?) built scope, and the serial number does not fit the Beaverton "B" serial numbers distinguishing "early" and "later" constructions. I think you're describing the layout as depicted in the later service manual:

https://w140.com/tekwiki/images/5/55/070-1861-00.pdf

I'm still relatively new myself. I sometimes speak as if I know what I'm talking about. But this is what I think is going on.

Dave


Bill
 

Page 174 in the 465 Service manual is the schematic of the scope's power supply.

On page 168 just underneath R1460 (Potentiometer) you can see R1463, CR1465, VR1414 and R1441. On my scope there are only two resistors in that spot and no diode.

Will just have to go hand over hand until I find the bad component on the -8vdc rail. My old 453 has an excellent manual but the manual is for it's serial number.

Bill


Bill
 

No it is a 465.
Bill


Tom Lee
 

Ah, thanks, Raymond.

Sent from my iThing, so please forgive brevity and typos

On Apr 18, 2021, at 15:23, Raymond Domp Frank <hewpatek@gmail.com> wrote:

On Mon, Apr 19, 2021 at 12:07 AM, Bill wrote:


No “B”.
That makes it a Guernsey-produced instrument and a rather late one at that. Non-US (i.e. non-B) numbers cannot be cross-referenced to applicable serial numbers in the SM’s, which are all US (Beaverton-) related.

It’s not a 465B by any chance? The faceplate should show it.

Raymond





 

On Mon, Apr 19, 2021 at 12:07 AM, Bill wrote:


No “B”.
That makes it a Guernsey-produced instrument and a rather late one at that. Non-US (i.e. non-B) numbers cannot be cross-referenced to applicable serial numbers in the SM’s, which are all US (Beaverton-) related.

It’s not a 465B by any chance? The faceplate should show it.

Raymond


Tom Lee
 

Are you sure about that?

Sent from my iThing, so please forgive brevity and typos

On Apr 18, 2021, at 15:07, Bill via groups.io <ko4nrbs=yahoo.com@groups.io> wrote:

No “B”.
Bill





Bill
 

No “B”.
Bill


 

On Sun, Apr 18, 2021 at 07:39 PM, Bill wrote:


Anyone have a service manual that covers a 465 scope serial number 107659
Is that B107659?

Raymond


Bill
 

I will do that later today. Found it frustrating to try and trace the circuits when components are not where they are supposed to be.
Bill


Dave Peterson
 

Interesting. I've been trying to sort out these intermediate scopes myself.

I have a pre-SN250K scope, but it appears to be mostly constructed of post SN250K boards, except for the vertical amplifier which is a mix of early and later constructions.

Have you tried using the schematic and layout of the post-SN250K manual? My experience has been that it is a good match to my SN177k scope. There are also component variations just due to the rapid evolution of some design details during this period for 465 construction. But the actual PCB seems consistent. Just the details of component stuffing can vary in small ways.

Can you put up a picture of the PS section of the A9 board you're dealing with?

Dave

On Sunday, April 18, 2021, 11:01:24 AM PDT, Bill via groups.io <ko4nrbs=yahoo.com@groups.io> wrote:

I found that manual but unfortunately it doesn't match up with my scope.
Thank you,
Bill


Bill
 

I found that manual but unfortunately it doesn't match up with my scope.
Thank you,
Bill


Dave Peterson
 

Bill,

There is a PDF link off the Tek Wiki page for 465 scopes:

https://w140.com/tekwiki/wiki/465


This is the direct link to the PDF:

https://w140.com/tekwiki/images/3/31/070-1330-00_465Service_OCR.pdf


Dave

On Sunday, April 18, 2021, 10:39:44 AM PDT, Bill via groups.io <ko4nrbs=yahoo.com@groups.io> wrote:

My Tektronix 465 has a -8vdc power supply problem.  The voltage is -2.6vdc.  All the other power supply voltages ae correct.

I need to be able to isolate the circuits as best I can when the correct components are located.  My problem is that the service manual I have is for higher serial numbers so it is just about impossible to find the components on the schematics.  The pictorials do not match my boards exactly.  Anyone have a service manual that covers a 465 scope serial number 107659.

Bill


Bill
 

My Tektronix 465 has a -8vdc power supply problem. The voltage is -2.6vdc. All the other power supply voltages ae correct.

I need to be able to isolate the circuits as best I can when the correct components are located. My problem is that the service manual I have is for higher serial numbers so it is just about impossible to find the components on the schematics. The pictorials do not match my boards exactly. Anyone have a service manual that covers a 465 scope serial number 107659.

Bill