Tek 465 degree-of-difficulty repair

[Bob Engelhardt]

I found a 465 at the dump with a sticker on it saying "Horizontal
deflection bad". Before I even power it up I thought that I'd get
opinions on how bad the problem likely is. Best case: "That happens all
the time & it's a bad Qxxx transistor in the framazazzle". LOL Worst
case: "It could be any number of things and you'll likely spend hours
and hours to fix a $100 scope". I do have the service manual & another
scope.

Thanks, Bob

[Rob]

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

[Mike Coon]

In article <sgih9...@news1.newsguy.com>, BobEng...@comcast.net
says...

That's what I call "right to repair". In the UK it is not permitted to
take kit away from a dump, in case you are not as competent as you think
you are...

[Chris K-Man]

_________

Where do you think I got my stash of spare TV remotes from?

If a bar's got a Sony on the wall, in Vivid mode, Im can whip out
my Sony remote, and at least put it in Standard mode.

[legg]

It's a relatively simple part of the scope, if it's
an accurate diagnosis.

Helps if you have a working scope to repair this one.

https://groups.io/g/TekScopes/messages

RL

[Phil Allison]

bobenge...@gmail.com wrote:
=========================

** You are asking a " Schrodinger's Cat " type question.

The cat can be thought dead or alive - until you open the box.


...... Phil

[Trevor Wilson]

**Who knows? Download a service manual and get to work. The 465/b is an
excellent 'scope and built to last a VERY long time.

[three_jeeps]

I second the motion to join & post on the TekScopes message board. A lot of *very* knowledgeable ppl hang out there. IMHO, I'd spend 15 mins with it plugged in to understand more clearly the characteristics of the malfunction. If you put that info in your post, you might get a bit more of an answer along the lines you are looking for.
A 465 is a very well-known and popular scope. It was standard gear for DEC and IBM field circus back in the day, and a typical scope in a lot of college EE labs.
good luck
J

[Eike Lantzsch, ZP6CGE]

Thats the moment I secretly use my TV-B-Gone

Kind regards, Eike

[Phil Allison]

three_jeeps wrote:
------------------------------

>
> I second the motion to join & post on the TekScopes message board.
> A lot of *very* knowledgeable ppl hang out there.

** Antique scope freaks .....

> A 465 is a very well-known and popular scope.
> It was standard gear for DEC and IBM field circus back in the day,
>

** Had the use of the earlier & similar a Tek 463 for a couple of years.
On loan, from a Sydney based IBM engineer - son of the man I worked for.
Not very fond of it cos it lacked the one thing a good analogue scope needs.
A sharply focused trace.

The PDA ( post deflection acceleration ) tube was poor and you could see the blurring effect
of the acceleration grid behind the face of the CRT all the time.
It also had an external, lamp lit graticule - very clunky compared internal graticule tubes
that most scope used from the 1980s onwards.



...... Phil

[Phil Allison]

Phil Allison wrote:
-----------------------

Correction:

** Had the use of the earlier & similar a Tek 453 for a couple of years.

[Michael Terrell]

I have a Tektronix 453A, which has a very sharp focus. The 453 was 50 MHz with Nuvistor inputs, the 453A is solid state and works to 65 MHz. It was built for Telex, for their field techs. I've had it since 1988, and it was well worth the $400 that I paid for it.
I now have two Tektronix 2465A scopes. Four channel, 350 MHz.

[Trevor Wilson]

**The 453 used Nuvistors in parts of the machine. It also had this
horrible 'flyscreen' covering the CRT display. Like almost all Teks,
mine worked flawlessly.

[Phil Allison]

Trevor Wilson wrote:
==================

Phil Allison wrote:
>
>
> > ** Had the use of the earlier & similar a Tek 453 for a couple of years.

> **The 453 used Nuvistors in parts of the machine. It also had this
> horrible 'flyscreen' covering the CRT display.

** I'm sure that is a projection from the internal PDA mesh.
Defocussing the trace made it really obvious.

There was a plastic graticule over the CRT screen.

My current scope has a mesh PDA mesh that is quite invisible.
The CRT is by Matsushita - type 140CBG31



.... Phil

[Chris Jones]

On 01/09/2021 08:54, Phil Allison wrote:
> three_jeeps wrote:
> ------------------------------
>>
>> I second the motion to join & post on the TekScopes message board.
>> A lot of *very* knowledgeable ppl hang out there.
>
> ** Antique scope freaks .....
>
>> A 465 is a very well-known and popular scope.
>> It was standard gear for DEC and IBM field circus back in the day,
>>
>
> ** Had the use of the earlier & similar a Tek 463 for a couple of years.
> On loan, from a Sydney based IBM engineer - son of the man I worked for.
> Not very fond of it cos it lacked the one thing a good analogue scope needs.
> A sharply focused trace.

Low-bandwidth scopes tended to have better focus. The noise of the
vertical amplifiers can of course be reduced by filtering out the high
frequency noise afterwards. The trace on a 475 gets quite a bit sharper
when it is set into low-bandwidth mode. Perhaps it is an argument for
having two scopes, one with a sharp trace and one with more bandwidth. I
haven't got any reasonable justification for the number of analogue
scopes that I have though, apart from "that looks too good to stay in
the dumpster".

[Phil Allison]

Chris Jones Pommy Shit wrote:
====================

>
> > ** Had the use of the earlier & similar a Tek 463 for a couple of years.
> > On loan, from a Sydney based IBM engineer - son of the man I worked for.
> > Not very fond of it cos it lacked the one thing a good analogue scope needs.
> > A sharply focused trace.
>
> Low-bandwidth scopes tended to have better focus.

** Dopes tend to say idiotic things ...

> The noise of the vertical amplifiers

** Totally irrelevant to my comments.

Just as fuckwits like you are to normal humans.



...... Phil

[None]

On Mon, 30 Aug 2021 09:17:56 -0700, Thec...@tards.shortbus.edu obsessed:

> If a bar's got a Sony on the wall, in Vivid mode, Im can whip out my
> Sony remote, and at least put it in Standard mode.

Dumbfuck OCD. FCKWAFA!

[Michael Terrell]

On Thursday, September 2, 2021 at 8:30:51 AM UTC-4, Chris Jones wrote:
>
> Low-bandwidth scopes tended to have better focus. The noise of the
> vertical amplifiers can of course be reduced by filtering out the high
> frequency noise afterwards. The trace on a 475 gets quite a bit sharper
> when it is set into low-bandwidth mode. Perhaps it is an argument for
> having two scopes, one with a sharp trace and one with more bandwidth. I
> haven't got any reasonable justification for the number of analogue
> scopes that I have though, apart from "that looks too good to stay in
> the dumpster".

Many wideband scopes can be switched to 20MHz mode to mask harmonics and stray RF pickup..

[Phil Allison]

terrell....@gmail.com wrote:
---------------------------------------------

>
> Many wideband scopes can be switched to 20MHz mode to mask harmonics and stray RF pickup.
>

** Also to reduce visible noise coming from the *input stages* when using the most sensitive vertical settings.

I have a band limiting filter ( 22Hz to 20kHz, -12dB/oct ) I can insert after some audio device that outputs noise above that range, CD players & Class D stuff for example.
But one really needs a multi stage, ceramic filter to do the job well.

Early CD players by Sony had them fitted - made by Murata.

Down 1dB at 22kHz and then -100dB /oct.
Nice.


...... Phil

[Paul S. Barford]

That has to be the *dumbest* exposition of the Copenhagen
Interpretation I've ever seen. I'd stick to soldering bits of wire
together IIWY.

--

Dr. Paul S. Barford, Rochester New York, USA
ps...@harvard.edu
PSB Consulting, NYC, NY and Cambridge MA