Tektronix 7104 for 100 eur?

[PartialDischarge]

Would you get a working tektronix 7104 with 4 modules installed (dont know exactly which ones), no probes, for 100eur?
Im not very fond of analog scopes, but I know this thing is a beast although Im not sure what I would use it for...

[Gyro]

I might, IF I had the space, but I'd want to be a lot more sure what I want to use it for.

It probably depends on the modules too, for instance if it had a couple of sensitive differential input modules... You need to know what it's got. Post a picture if possible.

[PartialDischarge]

Will try to post some.
Actually I was thinking of getting it just for the HV supply inside (12kV and 2400V ??), could come in handy for my lab.

[Gyro]

There are easier and safer ways of getting high voltages. The ones in a scope are heavily embedded. It's +12kV and MINUS 2400V, I don't think you will get around that. The supplies will take very little abuse too, they are very specific purpose (ie. driving the tube), they will fry very easily if you short them for instance.

Personally I'd turn it on, put on a decent waveform, lower the lights and enjoy! 

[PartialDischarge]

Personally I'd turn it on, put on a decent waveform, lower the lights and enjoy! 

Agreed, but I'd better wait for wintertime to do that 

[iDevice]

100€ is certainly good value for money.

But it depends on what you would use it for.
I don't now if you are aware of the "specialty" applications of this particular model.
The 7104 is a 1GHz Micro Channel Plate CRT scope. It uses a special MCP tube to amplify the electron flow reaching the phosphor so that even a 1GHz signal is still visible.

The drawback is that this CRT is not as bright and smaller that the standard CRT and cannot be used for more than a few minutes at a time at very dim luminosity or even seconds at normal luminosity to preserve the MCP plate which unavoidably looses a bit of life each time.
Which means that most of the 7104 still living are often heavily burned by now.

Besides and because of this drawback, without the proper plugin's, this model is not very interesting in comparison with other 7000 series chassis.
You need 7A29, or at least 7A19 vertical plugin's and a couple of 7B15/7B10 timebases.
If this is the case and you have a need for looking at 1GHz signals then yes, this boat-anchor has still a degree of usefulness.

As my digital scope is limited to 500MHz, I still use my 7104 for signals beyond this BW.
With a 7A29 plugin, I can still sync and see stuff beyond 2GHz (uncalibrated of course), but I wouldn't consider it for everyday use.
 

[Rupunzell]

Errrr, no.

7104 is bright enough to burn you eyes out. They work fine as a daily user Tek 7000, which is what has been done with the three that live around here. It is one of the best of the Tek 7000 series. There are little if any trade offs when compared to the other varieties of Tek 7000. The micro channel CRT has an electrons hitting the CRT integrator that essentially watches the amount of energy whacking the CRT, once the internally set limit has been reached the E gun shuts down to protect the CRT with a red LED on. The yellow LED varies intensity to not the amount of viewing time available. Under normal scope usage conditions, viewing time is not really an issue. Tek 7104 is compatible with all Tek 7000 plug ins made.

Tek's micro channel plate CRT technology was also used on the 2467 portable and 11302. 

Where the 7104 comes to it's own is the ability to see low duty cycle events, nano to subs nanosecond pulse events that occur over uS or mS. This is one of the reasons why th 7104 was so favored by the Physics and Optical folks. It also has a horizontal BW of 300-350Mhz allowing X-Y displays that are not possible on other CRT scopes. It remains one of my all time fave Tek 7000 main frames, remains the daily user scope.

http://www.vintagetek.org/wp-content/uploads/2011/10/7104-Springer-article-email-res.pdf

http://readingjimwilliams.blogspot.com/2011/08/scope-sunday-4.html


Bernice

100€ is certainly good value for money.

But it depends on what you would use it for.
I don't now if you are aware of the "specialty" applications of this particular model.
The 7104 is a 1GHz Micro Channel Plate CRT scope. It uses a special MCP tube to amplify the electron flow reaching the phosphor so that even a 1GHz signal is still visible.

The drawback is that this CRT is not as bright and smaller that the standard CRT and cannot be used for more than a few minutes at a time at very dim luminosity or even seconds at normal luminosity to preserve the MCP plate which unavoidably looses a bit of life each time.
Which means that most of the 7104 still living are often heavily burned by now.

Besides and because of this drawback, without the proper plugin's, this model is not very interesting in comparison with other 7000 series chassis.
You need 7A29, or at least 7A19 vertical plugin's and a couple of 7B15/7B10 timebases.
If this is the case and you have a need for looking at 1GHz signals then yes, this boat-anchor has still a degree of usefulness.

As my digital scope is limited to 500MHz, I still use my 7104 for signals beyond this BW.
With a 7A29 plugin, I can still sync and see stuff beyond 2GHz (uncalibrated of course), but I wouldn't consider it for everyday use.

[David Hess]

I would jump at the chance of getting a working or repairable 7104 for 100eur.

Will try to post some.
Actually I was thinking of getting it just for the HV supply inside (12kV and 2400V ??), could come in handy for my lab.

You want one of the greatest analog oscilloscopes ever made just for its unremarkable power supply?  This just shows that Europeans do not deserve such fine test equipment and I will remember your post next time someone from Europe complains that used Tektronix gear is so rare and expensive over there.  Look for a junked 7603 or 7704 instead if you want a power supply.

Besides and because of this drawback, without the proper plugin's, this model is not very interesting in comparison with other 7000 series chassis.
You need 7A29, or at least 7A19 vertical plugin's and a couple of 7B15/7B10 timebases.
If this is the case and you have a need for looking at 1GHz signals then yes, this boat-anchor has still a degree of usefulness.

As my digital scope is limited to 500MHz, I still use my 7104 for signals beyond this BW.
With a 7A29 plugin, I can still sync and see stuff beyond 2GHz (uncalibrated of course), but I wouldn't consider it for everyday use.

The 7104 is still useful with lower bandwidth vertical plug-ins when dealing with low repetition rate signals.

The very common 400 MHz and 500 MHz 7B80/7B85/7B92A timebases are almost as good as the 1 GHz 7B10/7B15.  I would actually prefer the 7B80/7B85 since they support peak-to-peak automatic triggering and the 7B10/7B15 do not and I rarely use the fastest timebase settings on my 7904 or other high bandwidth oscilloscopes even when viewing transition time limited signals anyway.

I thought maybe the 7104 delay line might be too short for the 7B80/7B85/7B92A timebases but the 7104 manual indicates that they work fine in it.

Of course if the 7104 in question comes with unspecified plug-ins, who knows what is installed.  My 7904 came with a 7D13, 7CT1N (why I bought it), and 3 other plug-ins that I have forgotten but probably included at least one 7B53A.

As far as the 7104 MCP CRT operating life, I do not think it is any worse than the 7834/7934 storage CRTs.  The real problem is that it is too easy to damage them through abuse.

[TAMHAN]

Please, don't fight - these Tek 7xxx series scopes do have their cult followers. So, maybe selling it on would be a great idea...or it will maybe endear itself to you after having saved it from the scrap heap.

And no, I wont trade it for the Fluke. But, in fact, the Fluke might soon get children at Tamoggemon. AFAIK, you have my email adress...tell me what you need a HV supply for, and maybe we have a deal.

[tggzzz]

I would jump at the chance of getting a working or repairable 7104 for 100eur.

In the recent UK sale, with condition unknown, arrange your own packing/shipping:
Tektronix 7613 oscilloscope, 100MHz inc: 7A18, 7B53A £10
Tektronix 7603 oscilloscope, 100MHz inc: 7A18 trace amps, 7B53A dual time base £11
Tektronix 7704A oscilloscope, 200MHz inc: 7A26 trace amps, 7855 delay time base, 7880 time base £10
Tektronix 7704 oscilloscope, 200MHz inc: 7A26 trace amps, 7885 delay time base, 7880 time base not sold
Tektronix 7704 oscilloscope, 200MHz inc: 7A26 trace amps, 7885 delay time base, 7880 time base £10
Tektronix 7603 oscilloscope, 100MHz inc: 7A18 trace amps, 7B53AN dual time base not sold
and I'm sure there were others, but I can't be bothered to find out!

[timb]

Will try to post some.
Actually I was thinking of getting it just for the HV supply inside (12kV and 2400V ??), could come in handy for my lab.

You want one of the greatest analog oscilloscopes ever made just for its unremarkable power supply?  This just shows that Europeans do not deserve such fine test equipment and I will remember your post next time someone from Europe complains that used Tektronix gear is so rare and expensive over there.  Look for a junked 7603 or 7704 instead if you want a power supply.

Your comment is a bit rude. I've lived in the US and I wouldn't throw all of you in the same stereotype bag, gun lovers, nascar fans, pizza eaters, fat asses, no second language spoken...

Right next to me I have an HP 3580a audio spectrum analyzer from the 70s!, which I love as an awesome piece of technology from that time, just so you know that I appreciate technology breakthroughs and engineering efforts more than most. But the thing is that that Tek 7104 would seldom be used at my home, probably never. Its bulky, its heavy, its a room heater and its uses are limited. I'd gladly sell it to someone who's interested in it but its so fkin heavy that I wont probably find a buyer for it.

So what you're saying basically is that I should keep it like a canvas in a wall, or like a statue on a table, as a piece of art. Anyway , lets see if I get it , and then I'll decide what I'll do with it

And lastly, yes we Europeans would like to have more USEFUL Tek, HP, Fluke, Anritsu, etc, equipment.

No, he's not saying you should hang it on the wall like a rare painting... What he's saying is that these scopes are getting rarer and rarer and the thought of someone buying one, just to gut it for the HV power supply is pretty barbaric.

It's a *ONE GIGAHERTZ ANALOG SCOPE* ffs! Sure, it's not a super modern DSO, but it's still very usable for looking at high bandwidth signals.

If you can't use it, resell it. I assure you there's plenty of people that will buy it, heavy or not.

[David Hess]

I would jump at the chance of getting a working or repairable 7104 for 100eur.

In the recent UK sale, with condition unknown, arrange your own packing/shipping:
Tektronix 7613 oscilloscope, 100MHz inc: 7A18, 7B53A £10
Tektronix 7603 oscilloscope, 100MHz inc: 7A18 trace amps, 7B53A dual time base £11
Tektronix 7704A oscilloscope, 200MHz inc: 7A26 trace amps, 7855 delay time base, 7880 time base £10
Tektronix 7704 oscilloscope, 200MHz inc: 7A26 trace amps, 7885 delay time base, 7880 time base not sold
Tektronix 7704 oscilloscope, 200MHz inc: 7A26 trace amps, 7885 delay time base, 7880 time base £10
Tektronix 7603 oscilloscope, 100MHz inc: 7A18 trace amps, 7B53AN dual time base not sold
and I'm sure there were others, but I can't be bothered to find out!

I was talking explicitly about a 7104.  I have 7000 mainframes which cover all of the ones you listed.  The 7104 is uniquely useful.

UPS has a habit of destroying well packed 7000 mainframes so I am bidding my time until one shows up locally but it is pretty unlikely.  Until then I have a fast storage oscilloscope and a fast DSO for low repetition rate high bandwidth signals.

[David Hess]

You want one of the greatest analog oscilloscopes ever made just for its unremarkable power supply?  This just shows that Europeans do not deserve such fine test equipment and I will remember your post next time someone from Europe complains that used Tektronix gear is so rare and expensive over there.  Look for a junked 7603 or 7704 instead if you want a power supply.

Your comment is a bit rude. I've lived in the US and I wouldn't throw all of you in the same stereotype bag, gun lovers, nascar fans, pizza eaters, fat asses, no second language spoken.

Having lived in the US all my life, I would.

I elected to deliberately channel Linus Torvalds to make a point.

So what you're saying basically is that I should keep it like a canvas in a wall, or like a statue on a table, as a piece of art. Anyway , lets see if I get it , and then I'll decide what I'll do with it.

I would hope that it would get used rather than being chopped up for an unremarkable power supply.

[Electro Fan]

A 7000 series and a 7104 especially would be a very nice and likely useful addition to most benches but it will take up a significant amount of space and the bench needs to be very sturdy.  I don't know if my experience with the 7000 series is representative but so far my experience indicates that for every 2 plugins you buy on eBay 1 will work very well and the other will either need to be at least somewhat repaired (but probably not totally) or it will become a parts donor.  The good news is that eBay seems to have a steady supply.  I haven't found other abundant sources of 7000 plugins - others here might know where to find them.

As for the MCP, plenty of those are still operating well due in part to people who have owned them have likely appreciated their usefulness and their place in oscilloscope history, and also because of the built in circuit that times out off as needed. As noted in other posts the MCP was used in the 2467 models and the time out circuit seems to have been very thoughtfully designed.  My experience with a 2467B is that for every 1 time the time out circuit is annoying I am thankful and appreciative for it about 10 times.

If you know you are short on space or you don't have much use for the 7000 series or you aren't really enamoured with vintage Tektronix equipment I'd say either pass or resell it to someone would really enjoy it.  (Packing a 7000 for a successful shipment will require good packing materials and skills plus a labor of love; and the cost of packing materials and shipping will likely be a good fraction of 100 Euros.)

The 7104 is a classic among classics and it deserves better than being a power supply donor for some non-7000 repair project. 

[David Hess]

I don't know if my experience with the 7000 series is representative but so far my experience indicates that for every 2 plugins you buy on eBay 1 will work very well and the other will either need to be at least somewhat repaired (but probably not totally) or it will become a parts donor.  The good news is that eBay seems to have a steady supply.  I haven't found other abundant sources of 7000 plugins - others here might know where to find them.

That is my experience as well; about half of the plug-ins work with a minimum of maintenance, 25% require serious work which may involve diagnostics and just replacing one part acquired from a donor plug-in, and the last 25% are only worthy of being parts donors like a 7B53A with a broken cam switch.

I bought my first 7000 mainframe, a 7603, and a full set of plug-ins at the TRW ham radio swap meet in Manhattan Beach, Southern California.  There were piles of mainframes and plug-ins there 20+ years ago.  Swap meets with electronics located around aerospace centers (Southern California, Massachusetts, Chicago, Seattle) may still be a good source.  I also see a fair amount of 7000 gear on Craigslist in those areas.  The local market here around St. Louis dried up years ago after the aerospace industries moved on but I managed to pick up a 547 to go with my 545A.  Now *those* are space heaters but they *still* have features (dual delayed timebase and alternate sweep) not found in inexpensive modern DSOs.

[TAMHAN]

Hello,
what can I say. The 7104 - incidentially like the super expensive TS-81000 from iwatsu - definitely are in a league of their own.

The question is of one needs them. At Tamoggemon H.Q., we answered this question with no and went for a TDSxxx 1GhZ unit. But from a pure nice to have aspect, if I would get one for so cheap...

[TerraHertz]

YES! I would (if I had 100 EUR atm.)
Because I already have a 7104, which was working when I got it but due to a stupid, clumsy goof, I broke it badly during cleaning. Fumbled the EHT plug while disconnecting it, about half an hour after running the scope. The intention was to short the male plug to chassis, but instead I dropped it past the deflection board, which it arced to. Sob... all those unobtainium custom HF amp chips.

Hence I have a very frustratingly dead 7104. For which I'd love a spare main power supply and deflection board.

Maybe if you do strip yours, we can do a deal?  Tragic though it is to scrap a 7104.

[David Hess]

YES! I would (if I had 100 EUR atm.)
Because I already have a 7104, which was working when I got it but due to a stupid, clumsy goof, I broke it badly during cleaning. Fumbled the EHT plug while disconnecting it, about half an hour after running the scope. The intention was to short the male plug to chassis, but instead I dropped it past the deflection board, which it arced to. Sob... all those unobtainium custom HF amp chips.

Hence I have a very frustratingly dead 7104. For which I'd love a spare main power supply and deflection board.

Maybe if you do strip yours, we can do a deal?  Tragic though it is to scrap a 7104.

7104s with broken CRTs are available so you could get one of those and transplant your good CRT into it.

[PartialDischarge]

So here's the damn thing, I got it for 50€, and I'm already regretting it. It belonged to a woman whose husband had died. Im still not sure if everything works ok, and actually I was surprised to see that it has no BNC calibrator output, but it has the switches next to it.
The CRT looks ok, pretty bright and decent, although im no expert.

It has 2x 27A26 a 7B71 and a 7B10 modules. One of the modules has a sticker in german so it's probably where it came from.
I'll take some time to try to see what works and what doesn't and then I'll decide if this thing lives or not.
Terraherz what modules did you exactly need? 

[rsjsouza]

Mastertech, the oscilloscope looks very clean and, at 50 Euros, it is truly a bargain if you have the space. I wonder how much you would get from selling it as a whole or in parts.

[iDevice]

So here's the damn thing, I got it for 50€, and I'm already regretting it. It belonged to a woman whose husband had died. Im still not sure if everything works ok, and actually I was surprised to see that it has no BNC calibrator output, but it has the switches next to it.
The CRT looks ok, pretty bright and decent, although im no expert.

Looking at the state of the beast, it's a real bargain.
I got mine a few years ago for the same price and had to restore it extensively.
The screen looks bright because the dark filter has been removed I guess.
One thing you can do to see how much the CRT is burned is to move the trace just outside of the frame and then set the trace brightness much higher until the whole surface glow.
At that point, you will see the darker (burned) areas.
Don't do that more than a few seconds though.
If you don't see too much damage (the readout areas are usually the most visible but the most important area is around the center) then you have a winner that has a much greater value than what you paid for.

It has 2x 27A26 a 7B71 and a 7B10 modules. One of the modules has a sticker in german so it's probably where it came from.

Except for the 7B10 timebase which is matching the scope BW, the others are pretty "average" for a 7000.
The 7A26 are 200MHz vert. plugins which is a bit a bit disconcerting in such a mainframe, so I guess the previous owner had an assortment of plugins with at least one 7A29 or 7A19 but used these 7A26 when he needed 4 channels.
In your place, I would ask the lady if she has seen other plugins laying around in her late husband shack.
One thing for sure is that each of these plugins is already worth the amount you paid for the total...
 

[med6753]

It's too bad you are in Europe. If you were on this side of the pond I would make you an offer and relieve you of your "regret" in about 1 ns. 

[MadTux]

If you don't like it, please put that 'damn thing' back on ebay or give it to a fellow over here.

The sticker is most certainly from German Airforce, LW Werft 21=> Luftwaffe Werft 21.
Google says that was a unit on the Airforce base in Wunstorf.
Probably got decommissioned 1990 after Soviet Union broke down and someone took it home.

[PartialDischarge]

Good news, preliminary tests show that all 4 channels and 2 triggering modules work.
CRT looks ok except for a little burn at the left top corner readout. and the zero horiz line.
The last image shows a 450MHz sinewave fed directly from the signal generator (I know I know... )

[TAMHAN]

Hello,
looks great. Definitely not worthy of scrapping...

Tam (got your PM, respond soon)