Date   
Re: Restoration advice

Jean-Paul
 

Bonjour Alberto, you are fortunate as 7904A and 7104 are the best mainframes, I have the same.

The 2465/7B is the last TEK CRT scope and capable of decades more service.

Main issues: RIFA PSU X, Y caps

All electrolytics except PSU bus caps you mention.

SMD lytics on A5 board leaking and damaging board

A5 Dallas NVRAM battery, loss of CAL.

Chuck Harris and our moderator Dennis are the experts!

Please see the threads on 2465B A5 control SMD cap leakage and damage, and on Dallas NVRAM replacement.

See also the Tek 2465 teardown thread on EEVBLOG/test equipment,

https://www.eevblog.com/forum/testgear/tektronix-2465b-oscilloscope-teardown/

Full service manual is essential!

its very helpful on recapping, and answers everyquestion. Its now 67 pages long, so you need to search within the thread.

Bon chance!

Jon

Tek P6015A Probe ID pin/scale factor on 2465/7/B

Jean-Paul
 

Bonjour a tous:

I was testing several Tek P6015A 1000X HV probes with scopes that have the sensing of the probe ID pin.

Discovered on 2465/7/B the P6015A will not work, every unit (tested 4 scopes and 2 probes gives the trace ID, moves trace by ~ 1 div as if a probe ID button was pushed.

They do NOT give a proper trace, and the CRT scale factor is just "ID".

On 7804/7A26 or Yokogawa DL7440/DL1740, probe works fine but manual selection of scale, no use of probe ID pin.

Anyone ever try this? Seems undocumented.

The fix seems to be to isolate the probe ID pin from the scope BNC with a BNC extender M-F, but mechanically clumsy and dangerous as probe is bulky.

Mille mercis.

Jean-Paul

Re: 547 scope HV transformer problem. One practical solution.

fiftythreebuick
 

Ernesto, with some pieces of gear, it sure seems so! And for me, it would almost surely be a piece of tube type gear.

My best Type 555 definitely feels like an old dear friend! I have had it for 33 or 34 years or so and it's been next to my bench the whole time. Absolutely my favorite scope...

Tom AE5I

On Mon, Mar 2, 2020 at 02:03 PM, Ernesto wrote:


Tim, is it possible that inanimate objects gain a soul when they come in
contact with us? Could obsolete objects express gratitude when we give them a
new life or keep them alive?
If feel this with my 1995 Nissan Maxima. It is serving me for the last 25
years without being placed in the hand of a professional mechanic, and I feel
a bond when I drive it every couple of days.

Ernesto

Restoration advice

Alberto, IZ2EWV
 

Hi Eric,

Last year I bought from eBay a 7854. After one minute of operation, I heard
a whistle, a "pop" and a smell of something burning.

I guessed that it was the AC filter - which I had to replace for the same
issue on my 7104 and 7904A (and other instrument made by hp). But in this
case the faulty component was the RC snubber in parallel to the power
switch, placed inside the SMPS board.

Taking advantage of the servicing inside the SMPS, I checked the ESR of the
two large electrolytic capacitors (not replaceable with new ones, due to
the compact dimensions, as far as I know): to my surprise, they are still
OK, even with 30 years on their shoulders!

I decided to not follow a preventive overall replacement policy of the
electrolytic / tantalum capacitors inside my 2nd hand equipment, but to
repair it when a failure or a misalignment should occur.

The big issue is for that equipment, which employs SMD components: in my
experience, the smaller, the less enduring. I have a beautiful 2465B (1st
owner) that has been making me crazy, since a bad day it displayed - with
brightness reduced at the minimum, readable only in the darkness - TEST 05
FAIL 44. I troubleshoot it for long time, checked the voltages at the
socket on the main board, looked at the logic board (seemed to be clean),
replaced the three electrolytics and the DAC (voltages weren't OK),... Then
I closed it and put in the corner, until the will of revenge will arise
again!

73 de Alberto, IZ2EWV

Il giorno martedì 3 marzo 2020, Eric <ericsp@...> ha scritto:

So In building out the lab I have found that I have more then a few
pieces of Tektronix gear That I am servicing and maintaining. Given that I
have a great deal of gear now that was born WELL before me I want to future
proof it as much as possible. Especially some of the larger instruments
like the 7000 Frames and the curve tracers, also a few signal sources that
are in the type 100 series. The questions I am struggling with is how far I
should go with the preventive component replacement or should I leave alone
that which is working. I am asking more in the realm of the electrolytic
capacitors. Are the ALL dead or is it just the filters that need
replacement? Form working on computers that have aged it seems to be a
problem that sticks with the larger value caps with the bursting and the
leaking. To protect the transformers and extremely hard to replace gear I
have them online interactive power conditioning ups units. These are full
clean sign wave not modified sine wave that most ups units output when they
switch to batteries. Just hoping to make this gear outlast me and still be
very well taken care of.



Re: Restoration advice

Harvey White
 

What people have most problems with are the dipped tantalums.

In certain equipment, you replace them all wherever found.

I'd do a search of the newsgroup for a specific model to get an idea of what the problems are.

Harvey

On 3/2/2020 11:08 PM, Eric wrote:
So In building out the lab I have found that I have more then a few pieces of Tektronix gear That I am servicing and maintaining. Given that I have a great deal of gear now that was born WELL before me I want to future proof it as much as possible. Especially some of the larger instruments like the 7000 Frames and the curve tracers, also a few signal sources that are in the type 100 series. The questions I am struggling with is how far I should go with the preventive component replacement or should I leave alone that which is working. I am asking more in the realm of the electrolytic capacitors. Are the ALL dead or is it just the filters that need replacement? Form working on computers that have aged it seems to be a problem that sticks with the larger value caps with the bursting and the leaking. To protect the transformers and extremely hard to replace gear I have them online interactive power conditioning ups units. These are full clean sign wave not modified sine wave that most ups units output when they switch to batteries. Just hoping to make this gear outlast me and still be very well taken care of.


Restoration advice

Eric
 

So In building out the lab I have found that I have more then a few pieces of Tektronix gear That I am servicing and maintaining. Given that I have a great deal of gear now that was born WELL before me I want to future proof it as much as possible. Especially some of the larger instruments like the 7000 Frames and the curve tracers, also a few signal sources that are in the type 100 series. The questions I am struggling with is how far I should go with the preventive component replacement or should I leave alone that which is working. I am asking more in the realm of the electrolytic capacitors. Are the ALL dead or is it just the filters that need replacement? Form working on computers that have aged it seems to be a problem that sticks with the larger value caps with the bursting and the leaking. To protect the transformers and extremely hard to replace gear I have them online interactive power conditioning ups units. These are full clean sign wave not modified sine wave that most ups units output when they switch to batteries. Just hoping to make this gear outlast me and still be very well taken care of.

Re: Noob needs help with a 453 no sweep

toby@...
 

On 2020-03-02 10:16 PM, Brian Mathews wrote:
Hi Toby,

I have another 453 and although I'm not super experienced with it, I am
able to get a sweep with it. On this broken one I've flipped every switch
at least a hundred times so I'm pretty sure I'll have to follow the
previous reply to start taking some measurements. :D
Yes, after I posted I realised the symptom of no trigger would be no
trace at all, not a spot.

Best of luck, I look forward to hearing how you go with the restoration!

--Toby



On Mon, Mar 2, 2020, 17:51 <toby@...> wrote:

On 2020-03-02 5:40 PM, Brian Mathews wrote:
Hello, I am working on a neglected Type 453 right now and could use some
help on whether I am on the right track or not.

I have checked all voltages on the power supply and R&R the locked up
fan to get it freed up and working. Current situation is I have a dot on
the screen which is fully adjustable but absolutely NO sweep. I had CH2
working for a while (so I had 2 dots, still no sweep) but it is
intermittent and now not working again. I pulled all transistors and
cleaned the legs with deoxit and reinserted which seemed to help. Also
found most of the pcb mounting screws were loose, one had completely fallen
out and was wedged in by the wiring harness. Bottom line is I have tried
everything I can think of and can't get any sweep but I am getting a dot
that I can move up or down, side to side, etc. Tried swapping the Sweep
Gen transistors and a few others in that area where i could find another
component of the same value and made no difference.

I know this is a very basic suggestion, but I've been caught out by it:
Have you made sure the trigger settings will give you a sweep without a
signal to trigger on?

Forgive me if you've already ruled this out.

--Toby

(453 owner)


Thanks!! Brian W6BRY






Are your transistors growing whiskers in their old age?

John Williams
 

I suspect that many of you already know about this problem, but it is new to me. It relates to a number of 1960s era transistors causing failures in transistorized radios. The types of transistors described to have this behaviour are also used in early Tektronix equipment including the 321 and 321A oscilloscopes. According to the UK radio restorers people and investigated by NASA, tin “whiskers “ develop over time between the inner transistor case and connections inside. This causes hard to fix problems in the affected equipment. One temporary fix is actually tapping the transistor itself. I have a number of these little scopes that I parted out because I could not find the problem. Last night I actually fixed a 321 by tapping some of the transistors. These scopes have quite a few of the transistors susceptible to this problem, notably 2N2207 and OC170.

Information on this can be found by reading and following links within the following documents:

https://nepp.nasa.gov/whisker/anecdote/af114-transistor/index.html

http://www.vintage-radio.com/repair-restore-information/transistor_transistor-faults.html

https://nepp.nasa.gov/whisker/

There is a lot more but this is a good start. I now must go tap some more transistors.

Re: Noob needs help with a 453 no sweep

Brian Mathews
 

Hi Toby,

I have another 453 and although I'm not super experienced with it, I am
able to get a sweep with it. On this broken one I've flipped every switch
at least a hundred times so I'm pretty sure I'll have to follow the
previous reply to start taking some measurements. :D

On Mon, Mar 2, 2020, 17:51 <toby@...> wrote:

On 2020-03-02 5:40 PM, Brian Mathews wrote:
Hello, I am working on a neglected Type 453 right now and could use some
help on whether I am on the right track or not.

I have checked all voltages on the power supply and R&R the locked up
fan to get it freed up and working. Current situation is I have a dot on
the screen which is fully adjustable but absolutely NO sweep. I had CH2
working for a while (so I had 2 dots, still no sweep) but it is
intermittent and now not working again. I pulled all transistors and
cleaned the legs with deoxit and reinserted which seemed to help. Also
found most of the pcb mounting screws were loose, one had completely fallen
out and was wedged in by the wiring harness. Bottom line is I have tried
everything I can think of and can't get any sweep but I am getting a dot
that I can move up or down, side to side, etc. Tried swapping the Sweep
Gen transistors and a few others in that area where i could find another
component of the same value and made no difference.

I know this is a very basic suggestion, but I've been caught out by it:
Have you made sure the trigger settings will give you a sweep without a
signal to trigger on?

Forgive me if you've already ruled this out.

--Toby

(453 owner)


Thanks!! Brian W6BRY





Re: 547 scope HV transformer problem. One practical solution.

toby@...
 

On 2020-03-02 5:21 PM, ki6bge wrote:
Could be. I know that I have resurrected many older pieces of equipment and
I definately feel the Karma. I got a 1969 dodge dart from a co-worker for
free if I could fix it. $35.00 timing chain was all it took. 2 years later
I put a new engine in it, repainted it and put a new vinyl roof on it. My
girlfriend and drove it to Carmel Ny The Sea and got married. My father and
mother grew up during the great depression and taught me "waste not, want
not. I'll be 70 in October and just because we get old doesn't mean we're
not useful.
What a great attitude! May we all continue to repair and reuse, and pass
this on to future generations.

Kudos!
--Toby



On Mon, Mar 2, 2020, 14:03 Ernesto <ebordon@...> wrote:

Tim, is it possible that inanimate objects gain a soul when they come in
contact with us? Could obsolete objects express gratitude when we give
them a new life or keep them alive?
If feel this with my 1995 Nissan Maxima. It is serving me for the last 25
years without being placed in the hand of a professional mechanic, and I
feel a bond when I drive it every couple of days.

Ernesto




Re: Noob needs help with a 453 no sweep

toby@...
 

On 2020-03-02 5:40 PM, Brian Mathews wrote:
Hello, I am working on a neglected Type 453 right now and could use some help on whether I am on the right track or not.

I have checked all voltages on the power supply and R&R the locked up fan to get it freed up and working. Current situation is I have a dot on the screen which is fully adjustable but absolutely NO sweep. I had CH2 working for a while (so I had 2 dots, still no sweep) but it is intermittent and now not working again. I pulled all transistors and cleaned the legs with deoxit and reinserted which seemed to help. Also found most of the pcb mounting screws were loose, one had completely fallen out and was wedged in by the wiring harness. Bottom line is I have tried everything I can think of and can't get any sweep but I am getting a dot that I can move up or down, side to side, etc. Tried swapping the Sweep Gen transistors and a few others in that area where i could find another component of the same value and made no difference.
I know this is a very basic suggestion, but I've been caught out by it:
Have you made sure the trigger settings will give you a sweep without a
signal to trigger on?

Forgive me if you've already ruled this out.

--Toby

(453 owner)


Thanks!! Brian W6BRY


Re: Push-push switch repair (need some theory of operation)

EJP
 

Problem solved, it is all working. I had merely forgotten to set the vertical amplifier to DC coupling. Clue, after sensing that all the voltages at each end of R238/248 were being switched correctly, was that when I pushed the PNP button in, the dot went to top right but then flashed down to bottom right, i.e. as the coupling capacitor in the vertical amplifier charged up.

Many thanks to Ke-Fong and to Dennis for locating the switch. Great repair.

EJP

Re: CRT rebuilding

 

Those needing a bit longer CRT life may want to look at KE5FX's (John Miles) page
on CRT restoration.  I have used his technique on some HP units with good
success, and you may be able to do the same with a marginal Tek CRT.

see this page: http://www.thegleam.com/ke5fx/crt.html

If you are experiencing a dark-emitting CRT, you may want to explore this
method, as I said, it has worked for me. It cannot make the tube as new, or restore
it for ever, but for many, another 500-1000 hours is all they will ever need.

his page now includes a Tek example as well, so worth a try, and very well documented.


all the best,
walter

--
Walter Shawlee 2
Sphere Research Corp. 3394 Sunnyside Rd.
West Kelowna, BC, V1Z 2V4 CANADA
Phone: +1 (250-769-1834 -:- http://www.sphere.bc.ca
+We're all in one boat, no matter how it looks to you. (WS2)
+All you need is love. (John Lennon)
+But, that doesn't mean other things don't come in handy. (WS2)
+Nature is trying very hard to make us succeed, but nature does not depend on us.
We are not the only experiment. (R. Buckminster Fuller)

Re: Noob needs help with a 453 no sweep

Bob Albert
 

Time to stop shotgunning and make some careful tests.If there is no sweep, either it's not getting triggered or the sweep generator is broken.  Locate the circuits involved and measure some voltages.
I don't have the diagram in front of me so I can't be more specific.
Bob

On Monday, March 2, 2020, 02:54:09 PM PST, Brian Mathews <@W6BRY> wrote:

Hello, I am working on a neglected Type 453 right now and could use some help on whether I am on the right track or not.

I have checked all voltages on the power supply and R&R the locked up fan to get it freed up and working.  Current situation is I have a dot on the screen which is fully adjustable but absolutely NO sweep.  I had CH2 working for a while (so I had 2 dots, still no sweep) but it is intermittent and now not working again.  I pulled all transistors and cleaned the legs with deoxit and reinserted which seemed to help.  Also found most of the pcb mounting screws were loose, one had completely fallen out and was wedged in by the wiring harness.  Bottom line is I have tried everything I can think of and can't get any sweep but I am getting a dot that I can move up or down, side to side, etc.  Tried swapping the Sweep Gen transistors and a few others in that area where i could find another component of the same value and made no difference.
Thanks!!  Brian W6BRY

Re: 547 scope HV transformer problem. One practical solution.

Harvey White
 

I've always liked electronics.  Comments inline...

On 3/2/2020 4:12 PM, Ernesto wrote:
Hi Harvey,

"oh look, old technology" Again, the adjective OLD should not be used with technology. Technology is simply technology.
That's what *he* said.  I found it ironic that something that still worked (and has no equal, a 7000 series scope, at least currently) is dismissed as "old technology".  Old it may be, but it's mine, and it works.


The reason I got drawn again into electronics is that I got a suggestion to get rid of my OLD collection of records, and I wanted to listen to them one last time. So I pulled out of my closet my record player (OLD technology), a nice Technics SL-6 that had been unused for decades.
Dual 1229 here.
I connected it, turned on, and a smell of burning came out of the dead device. So I promptly found the service manual online and started to look and see what could have gone wrong. Possibly an electrolytic capacitor... This turntable has a direct drive and some servos to scan the disk and automatically position the stylus moving along the tracks. All this was interesting to learn.
Sounds nicely high end.
There were some waveforms to check in the troubleshooting procedures, and this brought the interest for an oscilloscope. And so I was drawn into reviving my OLD 547.
Let's see:  heathkit, then Tek 512, then 513, then a Telequipment D75,  then a 2430A, Kenwood CS6300(?), then into the 7000 series...

It turned out that I was able to troubleshoot the turntable without looking at waveforms. The problem was indeed a small electrolytic cap across the muting relay in the tonearm that had shorted out, and the driving transistor burned out. I had to learn and understand the design of the turntable, an interesting experience that gave me appreciation for this OLD equipment. And this, in turn, brought a desire to listen again of my collection of masterpieces of classical music, which I had put aside when I bought one of the first CD players on the market, a Sony CDP-102 ... that was also junked and broken and... which I ALSO repaired and got to work again.
That sounds good.  Some of those things I wouldn't have necessarily been able to fix, problems with getting parts are always the killer.
So now I am in an emotional renaissance of the past listening to my old 33 rpm records and CDs that had vanished from my memory, and I have a new appreciation for all the earlier (not OLD) technologies that gave me so much enjoyment several decades ago. This does not take anything away from the appreciation of today's modern technology, which will be "earlier" in some future.
heh, "old" is the operative word .... just ask someone sufficiently young.

You won't appreciate "old and working and mine" unless you've had to deal with "not mine" and you want to do something that needs that equipment.

Much of the "younger" generation has not had to deal with not having things, let alone having the need for such test equipment, or understanding what to do with it.  Much of today's technology at the level that most experimenters use it doesn't need a scope, and is prepackaged and modular.

Harvey



Ernesto


Noob needs help with a 453 no sweep

Brian Mathews
 

Hello, I am working on a neglected Type 453 right now and could use some help on whether I am on the right track or not.

I have checked all voltages on the power supply and R&R the locked up fan to get it freed up and working. Current situation is I have a dot on the screen which is fully adjustable but absolutely NO sweep. I had CH2 working for a while (so I had 2 dots, still no sweep) but it is intermittent and now not working again. I pulled all transistors and cleaned the legs with deoxit and reinserted which seemed to help. Also found most of the pcb mounting screws were loose, one had completely fallen out and was wedged in by the wiring harness. Bottom line is I have tried everything I can think of and can't get any sweep but I am getting a dot that I can move up or down, side to side, etc. Tried swapping the Sweep Gen transistors and a few others in that area where i could find another component of the same value and made no difference.
Thanks!! Brian W6BRY

Re: CRT rebuilding

 

If had had a good 2567B I would take you up on it!

I know that some tubes are a little more available, such as for the 465 and many for the 24XX. Haven't seen any NIB for a 7104 or even the 7904. Currently there is a used one for a 7603 listedon ebay at 200.  I don't have that model at the moment either, but I probably would go that high for a NIB tube.
  And CRT's used or otherwise are often not available at all for many of the older models that so may like to restore.

On Monday, March 2, 2020, 01:09:25 PM EST, victor.silva via Groups.Io <daejon1=yahoo.com@groups.io> wrote:

During all my years refurbishing Tek 24xx series I have been able to trade/barter/buy(when within reason) a large collection of NIB CRTs for the 2465x/45x and even 2 NIB 2467B CRTs.  If ThomasElectronics comes back with "$300-400 dollars, maybe more" I would certainly consider selling a few NIB 154-0850-01 CRTs for that.

--Victor

Re: 547 scope HV transformer problem. One practical solution.

ki6bge
 

Could be. I know that I have resurrected many older pieces of equipment and
I definately feel the Karma. I got a 1969 dodge dart from a co-worker for
free if I could fix it. $35.00 timing chain was all it took. 2 years later
I put a new engine in it, repainted it and put a new vinyl roof on it. My
girlfriend and drove it to Carmel Ny The Sea and got married. My father and
mother grew up during the great depression and taught me "waste not, want
not. I'll be 70 in October and just because we get old doesn't mean we're
not useful.

On Mon, Mar 2, 2020, 14:03 Ernesto <ebordon@...> wrote:

Tim, is it possible that inanimate objects gain a soul when they come in
contact with us? Could obsolete objects express gratitude when we give
them a new life or keep them alive?
If feel this with my 1995 Nissan Maxima. It is serving me for the last 25
years without being placed in the hand of a professional mechanic, and I
feel a bond when I drive it every couple of days.

Ernesto



Re: 547 scope HV transformer problem. One practical solution.

 

Tim, is it possible that inanimate objects gain a soul when they come in contact with us? Could obsolete objects express gratitude when we give them a new life or keep them alive?
If feel this with my 1995 Nissan Maxima. It is serving me for the last 25 years without being placed in the hand of a professional mechanic, and I feel a bond when I drive it every couple of days.

Ernesto

Re: 547 scope HV transformer problem. One practical solution.

ki6bge
 

I love my Tektronix 2215. It does what I need and is very accurate. I got
it from a friend in non-operative condition. A set of capacitors brought it
back to life. It used my Fluke 77 to troubleshoot it.
Have fun. The satisfaction of restoring old equipment feels so good.
Tim Sutton
KI6BGE
Torrance, CA

On Mon, Mar 2, 2020, 13:31 satbeginner <@satbeginner> wrote:

My trip into memory lane - read "Old Technology" was this one:

Just for the fun of checking if I could still repair an "older" radio, I
bought a broken Blaupunkt Palma AM/FM radio.

This thing was build in 1959, like myself, and has a solid state rectifier
and 6 tubes - or valves - depending on what side of the globe you live....

I used my -also old- Tektronix 2467B to check the voltages, oscillator,
etc. although that was a bit of an overkill...

Long story short, it works again, it has a really good sensitivity on the
FM, and has a remarkably low component count, and is actually fun to listen
to.

It's now my radio in my hobby room, where the HP, Keihtley, Wavetek,
Philips and Fluke stuff lives :-)

The thing I'm working on now is a near mint 2215A. Not the most impressive
scope, but nice and light to carry if I need to go somewhere.

I hope to receive some parts for it from Greece any day now.

Everything will get old at one point, but technology stays technology, and
some of it is just marvelous!!

Just my two cents,

Leo