Author Topic: Tektronix 7104 for 100 eur?  (Read 14432 times)

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Offline David Hess

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Re: Tektronix 7104 for 100 eur?
« Reply #25 on: August 02, 2016, 10:09:17 pm »
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.

Swapping the timebases will required to allow delayed sweep capability; the delaying timebase (7B71) goes into slot A and the delayed timebase (7B10) goes into slot B.  I would replace the 7B71 with a 7B85 to get automatic peak-to-peak triggering and delayed and delta delayed sweep capability with a time readout.  I would actually consider the 7B85/7B10 or 7B15/7B80 combination better than the official 7B15/7B10 combination but in practice the difference usually will not matter.

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.

Or he preferred using standard and inexpensive high impedance passive probes.  I mostly use 7A26s in my 400 and 500 MHz 7000 mainframes unless I must have higher bandwidth.
« Last Edit: August 03, 2016, 06:21:57 am by David Hess »
 

Offline george.b

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Re: Tektronix 7104 for 100 eur?
« Reply #26 on: August 03, 2016, 04:04:49 am »
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.

Quoted for truth.

Quote
So here's the damn thing, I got it for 50€, and I'm already regretting it.

I can't imagine in which parallel universe I'd regret getting a 1GHz analog scope for 50€...  :-//
Methinks you should sell it on to someone who'd properly appreciate that nice piece of equipment.
 

Online Electro Fan

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Re: Tektronix 7104 for 100 eur?
« Reply #27 on: August 03, 2016, 07:37:10 am »
Better sell it soon before you start to like it and then have to start buying plugins and probes  :)
 

Offline iDevice

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Re: Tektronix 7104 for 100 eur?
« Reply #28 on: August 03, 2016, 12:22:55 pm »
By the way, what does the "IDENTIFY" button do?, and if the red light "shutdown" blinks, it means that I have to lower the trace intensity?
It just moves up a bit the corresponding trace to identify it among all others.
Handy when you have 4 of them.
It also displays "IDENTIFY" on the corresponding readout.
There are even probes with a button you can push to remotely do the identification, nice when all your hands are occupied...
« Last Edit: August 03, 2016, 12:25:27 pm by iDevice »
 

Offline iDevice

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Re: Tektronix 7104 for 100 eur?
« Reply #29 on: August 03, 2016, 12:34:22 pm »

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.

Or he preferred using standard and inexpensive high impedance passive probes.  I mostly use 7A26s in my 400 and 500 MHz 7000 mainframes unless I must have higher bandwidth.

Yes, your right, that as well.
I only use my 7104 for high BW jobs so always 50 Ohms and when you need high impedance you go FET probe anyway.
I don't know, it's probably me but I never could see the 7104 as a standard daily use scope.
For me it's just like using a vintage '70 Ferrari to commute everyday to the office.
 

Online PartialDischargeTopic starter

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Re: Tektronix 7104 for 100 eur?
« Reply #30 on: August 03, 2016, 12:43:40 pm »
thanks, what about the red light "shutdown" blinking? it means that its about to turn off the beam cause im doing something wrong??
 

Offline iDevice

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Re: Tektronix 7104 for 100 eur?
« Reply #31 on: August 03, 2016, 03:01:38 pm »
thanks, what about the red light "shutdown" blinking? it means that its about to turn off the beam cause im doing something wrong??
Well, that's what I was talking about when I dared to say it is not an garden variety scope...
The flashing red led tells you that the MCP protection will kick in in a few seconds unless you seriously reduce brightness.
So you have to keep brightness of A & B traces quite low, as well as the readouts, to avoid this kicking after a while.
Sure, this scope can give you quite a bright spot when you need it but only for a few minutes.
This is the reason, I don't understand how this can be used as an everyday scope, unless your lab is a darkroom...
Waiting for the fanboys reaction now.  :)
 

Offline siggi

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Re: Tektronix 7104 for 100 eur?
« Reply #32 on: August 03, 2016, 03:22:36 pm »
This is the reason, I don't understand how this can be used as an everyday scope, unless your lab is a darkroom...
Waiting for the fanboys reaction now.  :)
What, wait, your lab is not a darkroom? You can do that? It's allowed, even?

My 2467 with its MCP CRT is my daily driver for general spelunking. I have to say the CRT-saver is seldom a nuisance. Given any high-repetition signal, it just isn't necessary to crank up the intensity to the point where it gets antsy. 
However, it now has competition from a HP 54622D, which - while being a digital scope - boots faster and is almost as responsive and intuitive to drive as the analog Tek.
 

Offline David Hess

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Re: Tektronix 7104 for 100 eur?
« Reply #33 on: August 03, 2016, 05:39:13 pm »
I only use my 7104 for high BW jobs so always 50 Ohms and when you need high impedance you go FET probe anyway.
I don't know, it's probably me but I never could see the 7104 as a standard daily use scope.
For me it's just like using a vintage '70 Ferrari to commute everyday to the office.

It is not just the high bandwidth which makes the 7104 special though; the MCP CRT is also good for low repetition rate signals and if care is used, life expectancy is not a worry.  Siggi (hey guy, I have not seen you post for 2 or 3 weeks on The List :)) mentions using his 2467 which also has an MCP CRT as his daily oscilloscope.

After I got my 500 MHz 7904, it replaced my 100 MHz 7603 for general use not because of its higher bandwidth since I prefer the 200 MHz 7A26 vertical amplifiers for the same reason the previous 7104 owner probably did but because the 24kV CRT is so much brighter and sharper than the larger 15kV CRT in the 7603.  A 150 MHz 7704 or 200/250 MHz 7704A would have the same advantage since they have the same 24kV acceleration voltage but the 7904 is what I have and I am not complaining.  Admittedly I would probably use any of these 24kV oscilloscopes if I had them in place of a 7104 until I needed its special capabilities.

And about the special capabilities of the 7104, how many devices allow one to experience apparent motion faster than the speed of light?  And as a single shot event visible under room lighting no less?
 

Offline Rupunzell

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Re: Tektronix 7104 for 100 eur?
« Reply #34 on: August 05, 2016, 06:58:59 am »
Two of Jim Williams fave O'scopes. Tek 547 & Tek 7104.



What a proper work scope cart should look like:


One needs to spend a decade or more driving a Tek 547 doing analog design, then an appreciation of just how good the 547 is for analog stuff can be. The CRT trace quality and definition has yet to be replicated in a production crt O'scope

JW memorial published this June 2016  EDN.

http://www.edn.com/design/analog/4442194/4/Remembering-Jim-Williams--5-years-later

After a while of observation and reading it appears analog O'scopes are much like cars of years gone by with manual gear shift, no power steering, no power brakes, no ABS, no traction control, no driver assist. The driver had to do most if not all the driving. If this is a performance car, it would mean essentially driver wears the car rather than driver being coddled by the car with numerous techno driving aids. In the case of the Tek 7104 in the world of Formula One race cars it would be much like this McLaren MP4/4 Senna once drove (now being driven by Lewis Hamilton).


The modern DSO in many ways is similar in concept to the modern F1 car with many technology based driver aids, energy recovery, finely balanced aero and much more... Better, maybe the are very different expression of technology intended to achieve different goals.



Bernice
 

Offline TerraHertz

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Re: Tektronix 7104 for 100 eur?
« Reply #35 on: August 05, 2016, 01:23:01 pm »
Terraherz what modules did you exactly need?  ;D

It's very kind of you to offer, but firstly I'm in Australia and quite broke atm, so the shipping probably would be a a problem.
But mostly, I just couldn't bear to be the cause of that nice scope being broken up for parts.

Really, if you hate it so much, list it on ebay once you've checked it's working. You should get a lot more than 50 EUR.
Also I second the idea to ask the widow about any other modules lying around. Maybe go there and look yourself, as she might not recognize them.  Surely there will be more appropriate ones, unless her husband didn't know what he was doing when he swi... acquired it from that base.

Speaking of inappropriate modules, here's my dead 7104 frame. The modules are just parked in it for storage, not even pushed in. But someone may get a laugh from the contrast.

If you actually do decide to part it out (for some reason) PM to remind me and I'll work it out.
« Last Edit: August 05, 2016, 01:25:55 pm by TerraHertz »
Collecting old scopes, logic analyzers, and unfinished projects. http://everist.org
 

Offline MadTux

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Re: Tektronix 7104 for 100 eur?
« Reply #36 on: August 05, 2016, 02:36:35 pm »

What a proper work scope cart should look like:


Bernice

I have almost the same stack in use at home  ;D:
« Last Edit: August 05, 2016, 02:42:14 pm by MadTux »
 

Offline rsjsouza

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Re: Tektronix 7104 for 100 eur?
« Reply #37 on: August 10, 2016, 09:55:20 pm »
So after a thorough cleanup, with a toothbrush, water and soap for the externals and 2 cans of contact cleaner spray for the internals, the scope found space next to my other stuff in a temporary setup as I'm looking forward to put together a place with all my 'other' toys together, lathe, mill, microscopes and other various scientific stuff
Uh-oh... That's how these things get in our lives... Taking space little by little...  :-DD

Nicely done! Enjoy your new scope!
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Oh, the "whys" of the datasheets... The information is there not to be an axiomatic truth, but instead each speck of data must be slowly inhaled while carefully performing a deep search inside oneself to find the true metaphysical sense...
 

Online Electro Fan

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Re: Tektronix 7104 for 100 eur?
« Reply #38 on: August 11, 2016, 02:08:52 pm »
So after a thorough cleanup, with a toothbrush, water and soap for the externals and 2 cans of contact cleaner spray for the internals, the scope found space next to my other stuff in a temporary setup as I'm looking forward to put together a place with all my 'other' toys together, lathe, mill, microscopes and other various scientific stuff

Now we're talkin' - the 7104 and Lab 1.0 look good and your Lab / Workshop 2.0 will probably be even more beautiful - Congrats

PS, after looking at your photo it would seem that you were destined to add the 7104 to you lab - it is a natural for a guy who appreciates classics like vintage radio, a HP 3580A, a Rigol 2072, Apple, and Solgar supplements :)
« Last Edit: August 11, 2016, 03:03:40 pm by Electro Fan »
 

Online Electro Fan

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Re: Tektronix 7104 for 100 eur?
« Reply #39 on: August 12, 2016, 05:35:13 am »
very nice, but you missed the NYC MTA subway mouse pad !  ;D

PS: about that radio, ill open someday a thread about it, a jewel fron the 40s, no modern plastics but bakelite inside, no rectifying diodes but a big fat valve...

That is a nice mouse pad.... as mouse pads go :)  Don't see a lot of mouse pads around these days but when it comes to not quite vintage but old school they are right in the mix :)  And bakelite outside and inside - that's very likely a vintage connoisseur's delight.  Don't forget to tell us the radio story....  Congrats again on the 7104!  (Wait til you see that you can observe signals in the picosecond realm.)
 

Offline JPortici

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Re: Tektronix 7104 for 100 eur?
« Reply #40 on: August 12, 2016, 05:52:12 am »
very nice, but you missed the NYC MTA subway mouse pad !  ;D

PS: about that radio, ill open someday a thread about it, a jewel fron the 40s, no modern plastics but bakelite inside, no rectifying diodes but a big fat valve...

That is a nice mouse pad.... as mouse pads go :)  Don't see a lot of mouse pads around these days but when it comes to not quite vintage but old school they are right in the mix :)  And bakelite outside and inside - that's very likely a vintage connoisseur's delight.  Don't forget to tell us the radio story....  Congrats again on the 7104!  (Wait til you see that you can observe signals in the picosecond realm.)
he'll try to break the scope risetime  ::)
(hint to the show us your square wave thread)

https://www.eevblog.com/forum/testgear/show-us-your-square-wave/msg587792/#msg587792
the madness starts at reply #5  :-DD
« Last Edit: August 12, 2016, 06:06:25 am by JPortici »
 


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