Date   

Re: Comments from Peter Keller on the 500 Series Scopes

John Atwood
 

Scope Usage at chez Atwood:

Main work bench: 561A with 3A6 or 3A74 and 3B4 plug-ins. I do mainly audio or low HF work here. No fan!

Second bench: 502A - again, mostly audio work. I like the sensitivity and dual beams.

Floating: 485 for RF work.

Audio listening room/bedroom: HP 130C - used for its symmetrical X-Y display (and low cost of acquisition!).

Repair project: 556 in excellent condition, but with a bad tunnel diode. Maybe the best of the 547 and 555? Only 840 Watts max!

Tube testing bench: 570 - Has 45 tubes and only two semiconductors ( 2 x 1N34A)!

Semiconductor test bench: 575

I’ve got a bunch of other scopes lying around waiting for repair or sale/donation: 465s, 2215, 561As, 647, etc.

Tek is great!

- John Atwood WA1ICI/7


Re: tektronix 7S14 batteries and time base question

Rick
 

Love this thread. I am super excited for the delivery of a 5S14N this coming Monday. I assume the batteries will be too low. I'm torn between replacing the batteries and adding holders or go the LED route.

Rick


Re: Tek 465 Negative 8 volt rail issues

Dave Peterson
 

Ed, how serendipitous.

I too am looking at a power supply cap issue. Haven't nailed it down yet, but similar line frequency "ripple". In my case the "ripple" is more like unregulated/unfiltered full-wave rectifier output on the 120v and/or 55v rectifier output - there's no significant capacitance. Question is, which cap.

What caught my eye here was "I have the caps on hand". Do you mean you have a stock of original 465 PS caps? Or do you mean you have a supply of modern caps?

I've looked at the "465 Power Supply Capacitor Replacement Guide", and am feeling a little more confident about attacking these caps. But I'm still on the fence about what route I would want to go. I'm very much the "ain't broke, don't fix" kind of guy, and I'll say I'm 51% biased towards keeping things as original as possible.

Curious to know what you meant by on hand, and if you have suggestions for sources.

Dave

On Thursday, December 24, 2020, 09:11:31 AM PST, Ed Pavlovic <kc9mmm@comcast.net> wrote:

I recently picked up a used Tek 465 scope for a price I liked and could pick
it up without having is shipped, and I'm getting started on checking it
over.  Everything works, although both traces even when grounded look like
there's an uncompensated probe attached.  But I figured I would look at the
low voltage power rails before I try to track down that issue.  Early 465,
with a B010XXX serial number, needs some cleaning and TLC.



All the test points for the rails except the -8 volt are within spec which
was low, so I hooked up a probe to the test point.  I'm getting a 1.75 volt
ripple at a frequency of 120 Hz, which makes me suspect the filter cap is
bad.  I have the caps on hand to replace all of those power supply caps on
all the rails, but before I go and do that, I just figured I would ask if I
should look at anything else on this power rail before I change the filter
cap so I don't kill it right away.  There's also a 33uf tantalum cap on that
rail to ground that I will replace as well as the service manual calls it
out as a 10 volt rated cap, which isn't much to spare on 8 volts.

I uploaded a photo to a folder I created of a shot of the ripple on the -8
volt rail here:



https://groups.io/g/TekScopes/photo/258534/0?p=Created,,,20,2,0,0



If the link doesn't work the name of the folder is "Tek 465 Negative 8 volt
rail" and there's only one picture in there.



Ed Pavlovic

KC9MMM


Re: Comments from Peter Keller on the 500 Series Scopes

Tom Norman
 

My TEK addition started off with a 7904 with a P11 CRT back 25 years ago. The hobby got put on hold, but came back to life about 5 years ago, with another 7904 (this time with P31), about 3 DSA602 variants and a raft of TM500/5000 stuff. About a year ago I decided I didn't know enough about tube circuits and what better way to learn than to pick up a 547. I (foolishly?) drove 800 miles to the recycler in WA to get that scope, and while there, the employee said "oh, by the way, another one just came in. Would you be interested?". I turned the corner and there was a 555 indicator....needless to say, it followed me home. I called it my lonely 555 since it didn't have a power supply, but a couple of fellows from TekScopes came to her rescue and found her a mate, and I found a couple of friends in the process. Next came a 575, and a bunch of plugins for the 500 scopes..... so I've got the "bug"... bad pun intended. (insert TEK "bug" here).

I love the fine trace, my inner mechanical engineer appreciates the mechanical design (my "car" analogy would be something like a 911), and the documentation (and ease of repair) make them a great platform to learn tube tech. All three that I (currently) have I'd call favorites, but the 555 is in my mind pretty special. Where else can you get 8 tiny traces on one CRT (a 556 I suppose) ? :) The 575 brings a lot of utility, but is special to me because it belonged to Charlie Rhodes, and came with a tube curve tracing adapter that he designed and built.

This may be restating Dennis' last point in the initial post, but ease of repair and what I've found to be a pretty extensive "off list" support network contributes to the relative lack of chatter... It's a joy for me to own these scopes and to have repaired them. And the repairing, for me, is particularly satisfying. Along those lines, I wouldn't mind seeing a few (more?) straight up repair reports on tekscopes from time to time.

Dennis and Peter- Thank you for making the books available to us. Can't hardly wait... and Dennis, hope you don't end up sprouting a hernia for your efforts...

Tom


Re: Comments from Peter Keller on the 500 Series Scopes

Don Bitters
 

That sir, is a serious addiction!  Have you considered counseling? (Tongue in cheek!! ;) !!).  I probably have 30+ pieces of ETE, but I am diversified - no more than 5 spectrum analyzers, and 3 O-scopes.Best wishes and a Merry Christmas to you and yours.Don Bitters


Tek 465 Negative 8 volt rail issues

Ed Pavlovic
 

I recently picked up a used Tek 465 scope for a price I liked and could pick
it up without having is shipped, and I'm getting started on checking it
over. Everything works, although both traces even when grounded look like
there's an uncompensated probe attached. But I figured I would look at the
low voltage power rails before I try to track down that issue. Early 465,
with a B010XXX serial number, needs some cleaning and TLC.



All the test points for the rails except the -8 volt are within spec which
was low, so I hooked up a probe to the test point. I'm getting a 1.75 volt
ripple at a frequency of 120 Hz, which makes me suspect the filter cap is
bad. I have the caps on hand to replace all of those power supply caps on
all the rails, but before I go and do that, I just figured I would ask if I
should look at anything else on this power rail before I change the filter
cap so I don't kill it right away. There's also a 33uf tantalum cap on that
rail to ground that I will replace as well as the service manual calls it
out as a 10 volt rated cap, which isn't much to spare on 8 volts.

I uploaded a photo to a folder I created of a shot of the ripple on the -8
volt rail here:



https://groups.io/g/TekScopes/photo/258534/0?p=Created,,,20,2,0,0



If the link doesn't work the name of the folder is "Tek 465 Negative 8 volt
rail" and there's only one picture in there.



Ed Pavlovic

KC9MMM


Re: Comments from Peter Keller on the 500 Series Scopes

c n
 

My 547 succeeded my first Tek scope, a 545B which I sold to a friend. It has a pristine CRT, that great thin trace which I love and it has been very reliable. I have a 1A1, type Q and and an aftermarket curve tracer plugins for it. I paid the princely sum of $43 for it in the early 90's at the surplus store of a large aircraft manufacturer I worked for here in Seattle before retiring. Unfortunately they no longer retail their surplus. Visible waveforms exceed its calibrated bandwidth considerably. Someone else on this forum has compared the 500 series to a Rolls Royce and I must concur. Unfortunately it is beginning to fall victim to the HV transformer failure and I have yet to decide what course of action to take for a cure.

--
Chuck N.
310A 547 453 475 2430A


Re: Comments from Peter Keller on the 500 Series Scopes

Arne Buck
 

There's a fellow here in Newton MA with an amazing collection of cars,
particularly tiny "Mini and Micro <https://www.bubbledrome.org/index2.html>"
cars, and sponsors a wonderful weekend culminating at the Larz Anderson
Transportation Mvsevm in Brookline MA. Many restored, many more not so,
each category stored in its own warehouse. He is wont to say, "I have this
nightmare in which I've died and my wife sells all my cars for what I told
her I paid for them."


Re: Comments from Peter Keller on the 500 Series Scopes

bobkrassa
 

The number of posts in recent years may not adequately represent the interest in 500 series scopes, because anyone who is aware of this group would search the messages before posting a question and would be very likely to find a comprehensive answer. This group is a tremendous resource!

Also, thanks to Dennis for everything you do!

Bob Krassa AC0JL


Re: Spectrum analyzer Tektronix 7L13 on mainframe Tektronix 7603

Attilio
 

Thanks tinkera123, I think my 7L13 is similar to yours. My 7L13 has the mechanical indicator for the reference level, but I know the latter had the LED display for the reference level indication.

Greetings and Merry Xmas to all


Looking for pictures of 067-0865-00 calibration fixture for A/P6303 current clamp

Jared Cabot
 

Hi all,

I recently picked up an A6303 (P6303) current clamp and I'd like to construct a calibration fixture to enable me to check and adjust it etc.
It looks just like an aluminium shroud with a hex standoff as a current path through the current clamp jaws, the shroud is connected to the shield on the BNC, the hex stand off connected to the center pin of the BNC via a 50ohm resistor on one side and shorted to the shroud on the other (To form a 50ohm terminated shorting loop).
I found a data sheet for it on the Tek Wiki website, and a picture of the side of it via Google, but I'm hoping someone who might have one can take a few shots from different angles with a ruler for size comparison.
Here is the one photo I have found online so far:
https://i.imgur.com/8zoJDiw.jpg

I'm pretty sure I know how it is constructed, but if I can get a few photos, I'll be able to see for sure.

Thanks!
Thanks!


Re: Comments from Peter Keller on the 500 Series Scopes

Morris Odell
 

My experience down here in Australia is very similar to some others although Tek scopes were never as easy to find as in the USA. The first one I ever saw whan I was a teenager in the 1960s was a 549 with a 4 trace plugin (M or 1A4). At that time I had a home made scope with a 5BP1 and gas tube timebase so the 549 was something absolutely amazing. The first Tek I owned was a 502 which I still have but haven't used for a long time. I've had many 500 series since including 524, 529, 531, 533, 541, 547, 549, 555, 556, 575, 581, 519 and a good selection of plugins and spare parts. I've never been into the 560 series. Some of the scopes have been given away over the years but I've still got quite a few including both double beam scoposaurii and the 519 in the unlikely event that I want to do some weird stuff ;-). At the moment my main bench scope is a 547/1A4 with a 7603 and 7834 available for use as the need arises.

The 547/1A4 really is a wonderful piece of industrial art, a pleasure to use and still exceptional even after 50 years. It's also easily repairable compared to more modern instruments. I cherish it every time I turn it on and consider myself very fortunate to have one.

Morris VK3DOC


Re: Help with 2712 Spectrum Analiser

Marcus - PP5MS
 

Hi everyone,

I would like to thank everyone who kindly gave me information and advice on how to proceed with the repair.

I downloaded the service manual and will start the work with a good visual inspection, changing the battery and checking the power supply.

Certainly I will publishing here the progress and I hope to have the 2712 fully functional soon.

Marcus - PP5MS


Re: Backlash/Play in the Delta Time Position Control on a 2236

 

Raymond,

I just bought one I saw on eBay that wasn't ridiculously priced (though, I suspect, it might have been the only one I saw, as I can't find any listings now). Maybe I should have been more careful, but I doubt that the eBay listing showed the full title page, so I couldn't have known what printing I was getting. TekWiki only seems to have the later printings. I should put a note in my printed copy that it doesn't match the unit.

I've seen the discussions of Tek SNs. It makes my head hurt. It did reveal, however, a half-memory about one of my dad's scopes (the 2213): what I recall is that he bought that scope essentially as soon as they were available, and the SN (B010299) confirms that memory. Not that I'm impressed by low model numbers, but any time I can have a pre-adolescent memory confirmed I'm happy.

-- Jeff Dutky


Re: Comments from Peter Keller on the 500 Series Scopes

Shaun M
 

Folks,

Best of the Season to everyone,

Just as a counterpoise to John's message, I have a big stable of old TEK CRT gear waiting to be restore and I am just about to retire from my day job (Materials Eng). I am relatively young (Apollo kid) so that I never encountered Tek CRT gear in my day job, but recognized the pedigree when I saw it.

Film cameras, well there is a specialty. I still shoot MF B&W and do my own developing. In fact I can claim some little expertise in chemistry and scanning, with taming high contrast films like TechPan and ATP 1.1 to produce wonderful prints.

So it will be over someday, but not today.

Shaun M

-----Original Message-----
From: TekScopes@groups.io <TekScopes@groups.io> On Behalf Of John Williams
Sent: Wednesday, December 23, 2020 20:54
To: TekScopes@groups.io
Subject: Re: [TekScopes] Comments from Peter Keller on the 500 Series Scopes

Hello and happy holidays to you all.

I have to agree with Peter that interest in 500 series scopes is declining. But I also have to say of course it is. Most of us who would have used them are also declining. Just like interest in other things that have been replaced by new technology such as collecting film cameras, mechanical toys and stamps. Even the crt color tv and computer monitors are gone. Remember DEC and Data General? Not only are the companies gone, but the entire minicomputer industry is history.

However there has been a lot of good interest in the old scopes since I started collecting them. Peter's book is just one example. Vintage Tek, Tekwiki, and the Tek museum all came to be since then. I would say that few people in the industry would ever consider using a tube scope, most don't even know that they exist. I often wonder what my wife will do with all this stuff once I am gone.

As far as the ones I have, I lost count a long time ago. Here is the link to my pictures, please count them for me.

https://na01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fphotos.app.goo.gl%2Frv7WNBPM61PsdLpj7&;data=04%7C01%7C%7C69c51ac937724a58c6d608d8a7bf90cd%7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C637443788513925330%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&amp;sdata=MdXB2FyzRTqq1JhWTmBSHLjYU5ym0Qe2nfMIKWJ60rU%3D&amp;reserved=0


Tek for time

stevenhorii
 

I did not think this belonged in any of the current threads. Besides Tek scopes, I also restore and mess about with time and frequency stuff. I use mostly quartz frequency standards and my favorites are the mil-spec ones from Frequency Electronics and the older high-stability ones made by Tracor/Sulzer. In fact, my reason for this posting is that I am looking for a particular Tracor/Sulzer frequency standard - a quartz model 2.5B or (preferably) a model 2.5C. I suspect that at least some members of this group have an interest in time and frequency stuff or may know other electronics folks who do. I have a pair of Tektronix 7L5 spectrum analyzers both with (I think - have to check) the L1 input module and one with the Option 25 tracking generator. Also a 7L14. I have not used these in years nor have I recently powered them up. I'd swap all three for a Tracor/Sulzer Model 2.5C that has an intact dewar inside the case and has all three outputs working. I do not need the power supply - I have plenty of those. I know there is a model 2.5 on eBay, but it is the early version and I have one of those (still a remarkably stable quartz oscillator and still working after what - 40 years?). I have repaired a few of these; usually one of the output amplifier stages after the divider stage quits and only one or two outputs work. Harder to fix is if the oven temperature control goes - if it's just the oven controller, that's not too bad, but it's hard to get to, and recalibrating the oven needs a precision thermometer of the platinum type (like the HP one). Yes, I use GPS as well. I have a couple of quartz standards and one rubidium standard that are disciplined by GPS. So they are pretty much like cesium clock precision. Anyone who has the Tracor/Sulzer I am looking for or knows of someone who does and is interested in the swap or sale, let me know off-list (sonodocsch at gmail dot com). Merry Christmas and Happy New Year to all of the group!

Steve Horii


Re: Comments from Peter Keller on the 500 Series Scopes

Dave Seiter
 

My first Tek scope was a working 502 I picked up at the Foothill fleamarket in about '79.  I had a Heathkit or Eico previously, and the 502 was so much better!  I spent endless hours just playing around with it, and used it to troubleshoot the early Commodore computers I built from dumpster parts. (It was a real testament to it's design that it could just barely trigger at the PCs frequencies (1MHz CLK), more or less!)  
Of the 80 or so scopes I have, the 500 series are:
502 (still have it!)R502511A514AD519 (3, including a 519 scopemobile)535 (I think- it's an old basket case)541545547 (2)RM547RM35A549551555575 (2- not scopes, but the same style & quality)
I love the narrow traces, the intuitive layout and the overall quality.  I have seen a few for sale locally in the past two years, but nothing I "needed".  One was a 536 for $20, but I was out of room at the time, and didn't need an XY scope.  Another was a 535 w/lots of plugins, but it had lived in a damp environment for years- there was a white corrosion film covering everything. As I was weighing my options, someone else snagged it.
-Dave

On Wednesday, December 23, 2020, 11:47:27 AM PST, Dennis Tillman W7pF <dennis@ridesoft.com> wrote:
Peter was disappointed that there didn't seem to be much interest in the 500
series of oscilloscopes. I thought it might be nice if Peter heard from how
many TekScopes members have 500 series scopes and what you like most about
your favorite model.


Re: Comments from Peter Keller on the 500 Series Scopes

John Williams
 

Hello and happy holidays to you all.

I have to agree with Peter that interest in 500 series scopes is declining. But I also have to say of course it is. Most of us who would have used them are also declining. Just like interest in other things that have been replaced by new technology such as collecting film cameras, mechanical toys and stamps. Even the crt color tv and computer monitors are gone. Remember DEC and Data General? Not only are the companies gone, but the entire minicomputer industry is history.

However there has been a lot of good interest in the old scopes since I started collecting them. Peter’s book is just one example. Vintage Tek, Tekwiki, and the Tek museum all came to be since then. I would say that few people in the industry would ever consider using a tube scope, most don’t even know that they exist. I often wonder what my wife will do with all this stuff once I am gone.

As far as the ones I have, I lost count a long time ago. Here is the link to my pictures, please count them for me.

https://photos.app.goo.gl/rv7WNBPM61PsdLpj7


Re: Backlash/Play in the Delta Time Position Control on a 2236

Ed Breya
 

OK, so it is the little pot on top. Regardless of which manual and part numbers are right, one thing that I recall is that pot is very flimsy (mechanically) for its application. A heavy handed user could over-torque it and bend or break it off the board, unless it has some kind of friction release over-run protection. With the number of part changes over the product life, I'm guessing there may have been two problems - one with having inadequate setting resolution, and possibly another needing mechanical changes for pot durability.

Ed


Re: Comments from Peter Keller on the 500 Series Scopes

snapdiode
 

I have a 547 with many plugins like the Type O, 1A1, 1A2, 1A5, 1A7, four 1S1's with accessories like P6032, Type 281 ans 282, four 1S2's.

I have a 531 but it is in pitiful condition, it was used by a cigar smoker before and it is coated in tar inside and out.

A 567 with 6R1A and a complement of sampling heads like S-1, S-2, S-3, S-4, S-52, S-6 and S-42.

And a box of stuff like those little epoxy bead 10mA tunnel diodes and Tek matched Nuvistors.

I also have a Type 132 power supply.

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