Vintage Tek Restoration pictures by Martin

[Cubdriver]

Thanks guys,  I will go carefully with this girl,  I don't think it has been switched on in a long time. 
My rough plan is a clean first,  I may find some problems,  then power supplies ,  filter caps,  then others.

This will be fun to watch - looking forward to seeing the old beast back up and running once again!

As for removing the tubes, for those miniature 7 and 9 pin ones, I grab the top and gently rock them in a circular motion (tough to describe, but easy to do - grasp near the exhaust tip and move in a small circle) whilst gently pulling upon them.  Make note of where they came from and put them back in the same sockets - some circuits are adjusted to the particular tube's characteristics and will wind up out of whack with the wrong tube.  (Vitally important on a fifty year old boat anchor, of course!!!). One nice thing about tubes is that they pretty much scoff at static, so they can be poked into a labeled piece of styrofoam without worry.

Be careful cleaning the tubes themselves - many use water soluble ink for the markings, and will quickly get naked if you hit them with window cleaner or the like.  It won't harm them, of course, and you'll be fine as long as you keep track of what's what, but I like having the manufacturer's markings on them.  The type number may be etched into the glass, in which case it will be fine, but logos, etc may go away.

And on that note, I should be asleep.  Best of luck with the new wigglescope!

-Pat

[Martin.M]

something to know for the first Classic Tek restoration.

There is the vertical slot with a plugin. The tubes there (you have CA? = 15 tubes), a lot of them are heated by the +100V DC, in series 150mA. Means when one of them is defect the complete plugin stop glowing. The summary of the dc filament is around 75 volt, then there are mostly 2 tubes inside in the mainframe they are also series connected in that circle! look for a 12AL5 in the chassis part what you can swing out. If this tube is not glowing it can be a problem in the plugin, must not be defect.

electrolytics of the PSU: they are mostly OK, the quality of them was timeless ! The paper covered elkos there are some where the case is NOT connected to the chassis, its an isolation.
Please be carefully, old Tek work with dangerous high voltage.

When cleaning take care, do not make wet transformers, special the HV transformer in the hv box must be dry.

on your picture you see at upside by one of the ceramic strips written voltages, +500 +350 +225 +100 -150V  there is the best place for checking them.
The -150V must be very exactly, it is the reference voltage for all others !

greetings
Martin

[AF6LJ]

This is going to be fun to watch.

[VK5RC]

Thanks Martin and Sue,  I have just done a little gentle cleaning,  small dry brush and vacuum nearby.
 Great to hear electrolytics are pretty reliable.
I have read the 545 doesn't have a fuse on one power supply rail,  the 545a and b does apparently,  that might be a useful 'update'  before switch on. 
Unfortunately work is pretty busy at present so updates may be slow.
Thanks.

[Martin.M]

dont be afraid to wash that old Tek with windows cleaner,
that oldies are not afraid from this prodedure, except HV Box + the large transformer.

[bitseeker]

Impressive restorations, Martin. So, when does the "Tek by Martin" museum open?

[VK5RC]

Hi Martin.M Thanks for the cleaning tip, I have been using
1 soft brush and vacuum nearby
2 Isopropyl alcohol (IPS) soaked cotton cloth strips
3 IPA soaked brush or cotton buds (Q tips) for really tight spots
4 Water for the tubes body, IPA for the pins
5 A very small wipe of 'Gun oil' metal preservative over metal threads or metal cases , some with a bit of surface rust see potentiometer body

I have only tackled the lower right side to date but found a piece of wire (about 4cm long) resting at the base of one valve, not attached in any way, possibly touching some of the pins, looks like it fell in there!! Hopefully it didn't short out too much.

I will tackle the rest slowly, then test the power supply, before fire up!
I think I might test each valve. a bit of a task!

As  a break form cleaning I took the fan out, it works    but the 3 vibration mounts have perished but found a very close fit from RS components

Some before and after photos of what I have done to date

[Martin.M]

that looks nice, good job 

The very first after power up is the check of -150V.
On your picture2 you see the pot for adjusting this voltage.
All other voltages of the PSU use this -150V as reference. The accuracy of -150V is desired to <1V

greetings
Martin

[VK5RC]

A quick minor update, the rubber fan mounts had gone soft and parted company, an RS component (see packet and part number in photo with one old and two new mounts) was a very good fit. :beer:
Fan cleaned , metal preservative on the aluminium,  light motor oiling and works nicely. 

[Martin.M]

the fan can also be washed with windows cleaner, following lubrication (silicone oil is nice bec. it is good for warm parts)

greetings
Martin

[Martin.M]

the next step in Tek restorations:

This is a rebuild Tek pounch for the little 211, 212, 213, 214 and 221,
it follows very fine the original design and color 

[etienne51]

the next step in Tek restorations:

This is a rebuild Tek pounch for the little 211, 212, 213, 214 and 221,
it follows very fine the original design and color 

My collection grew up a bit during the last few months. Now I have a 454 and a tiny 221! I also happen to have the original vinyl pouch for the 221, which is in great condition. Those are really nice scopes, and they are really clean as well. There are some technical issues that I'll have to investigate though.

Some of the Volts/Div ranges of the 454 are out of the display area on CH2, and the trace tends to jump quite a bit sometimes on that same channel. CH1 seems okay.

For the 221, the inverter circuit is dead. I did replace both of the power transistors, one of them was dead, and it worked again for a few minutes then died again. So it seems like a diode is faulty or something else. I need some more time to look into it. For now, it works nicely on external 12VDC!

[Martin.M]

amazing, another 221 

my 7k have now learned to count the frequency and display it in the readout,
by a 7D15 counter plugin.

greetings
Martin

[etienne51]

This is a nice 7K scope you have here! For the moment, I'll receive a Tek 547 in the next few weeks. It's been a long time I wanted this one. 

It's going to be shipped... and this monster weights so much, it has to be shipped in two packages to save on the shipping costs. The oscilloscope equipped with a 1A4 plugin in one package, and the mains transformer in another. The seller was kind and agreed to desolder all the wires on the transformer cleanly, and tag each one of them so I could put things back together with no issues at all. So that's really great!

The scope seems to be in a really good shape, it works fine, it's almost not dusty at all.

I'm wondering, about those big terminals on the transformer. I only have a Hakko FX888D soldering station, and I'm not sure that's powerful enough for something like that. I was thinking about getting a Weller soldering gun a while back, I didn't. I think it may be time to do so. Any advises on the best way to solder these? I know the Weller gun can go really hot and it would be great to use here, but I also don't want to overheat something in the process. I know silver solder is not necessary here, so I'll just go for my regular Kester 63/37 after cleaning the terminals.

[Martin.M]

why you remove the power transformer there?

greetings Martin

p.s. I am on the way to buy a 500`series TM Set, (a counter plugin, 2x multimeter plugin, a complex generator plugin and a small psu plugin) ugly expensive Tek gear... but I love that 
and 2 scope carts was found in a university.

[etienne51]

I wouldn't have done it if it was a local pickup. There is no ground shipping option to here, and the cheapest way do get something is through the postal service. I guess it's the same in all countries but, the maximum allowed package weight is 30Kg (66lbs). The package here was 37.5Kg (82lbs) so that's why!

More Tek stuff, that's great! I'll stick with the 547 for the 500-series scopes, unless one day I'm lucky and I find one locally. The only other model I'm really interested in would be the 556... One day I got a big 42Kg (92lbs) CRT computer monitor (Sony GDM-FW900) shipped, so the 556 is possible since it weights about the same, but definately later.

About the carts, I'll just build one for my 547 when it arrives. My custom cart probably won't be tiltable, but I'll see what I can do.

[Martin.M]

Tek 561, 564 (10mc storage), 310A are very glowing and will not exceed the 30kg

greetings
Martin

[etienne51]

Haha, I won't collect all of them like you do!

Right now I own the following models:

- Tektronix 310A (021904)

Simply one of the most amazing mechanical design that can be seen on a glowy test equipment. I got this one for my own collection only, pretty much. It's a masterpiece of vintage electronics test gear... It has a limited 4MHz bandwidth but definately enough for audio work for example and some analog projects.

- Tektronix 547 (013807) - soon -

The 547 is the top of the line when refering to single beam oscilloscopes of the 500-series. Makes use of all their technological advances, including the exclusive "Automatic Display Switching" feature, which can be really useful in some situations. Still not the fastest of the 500-series, which is the 585 as far as I remember.

- Tektronix 454 (B276947)

This is the scope that I'm using for my projects right now. This is the last model that makes use of those super sharp CRTs as far as I know. It follows the 453 which was designed for IBM when they asked for a portable oscilloscope that technitians could bring along with them when travelling. It was made for computer work back in the 60's - 70's. The 453 is the oscilloscope that introduced the rotating handle. The 454 is basically the 453 with a tripled bandwidth. The 454 is the fastest analog oscilloscope that uses only discrete components, no custom ICs.

- Tektronix 221 (B054502)

This one is a cute small oscilloscope! Litterally the nicest looking small analog oscilloscope to date. I tend to bring this one with me when I have to debug some analog circuits. This is the fastest model of this line, there are all the other models, dual trace storage, integrated dmm or simply dual trace. This one is single trace but has a 5MHz bandwidth which is a lot more useful to me than dual trace and 500kHz, but I can't compare signals.

- Tektronix 2465B (B055041)

This was my first Tek oscilloscope I got years ago, still my main bench oscilloscope. I was not into collecting Tek scopes back then... the madness started later. Before that I used a digital Rigol 1052E which was kind of horrible when trying to debug the analog circuits of my CRT driver boards project. This is probably the fastest portable analog oscilloscope. Despite being analog, its OSD has some really nice features that helps with quick measurements, but I should not get used to that too much

This is what I have in mind:

- Tektronix 585A

Simply the fastest of the 500-series oscilloscopes (excluding the oddball 519)! It reaches 100MHz easily with tube based circuitry. It has 4 transistors though, so it's not a vacuum tube only equipment, it's a hybrid. This one uses special plugins to reach such a high bandwidth but can still accept slower regular 1-series and letter-series plugins via an adapter.

- Tektronix 555 (aka "Triple Nickel")

This is a monster... This model is not the fastest dual beam in the 500-series, that would be the 556. But I admire this model with its separate power supply that uses a saturable reactor design to regulate the voltage of all the tube filaments in the entire oscilloscope. It takes not only the two vertical plugins, but also two horizontal timebase plugins. This is probably the most power hungry of all the Tek oscilloscopes with 1kW as far as I remember...

- Tektronix 556

If going for a dual beam Tek from the 500-series, this is the top of the line. It's, I guess, the replacement for the great 555 but unlike this one, it does not use horizontal plugins. It's like two Tek 547 in one box. A lot of combinaisons are possible between the top/lower beams, the A/B timebases and the left/right plugins. For example it's possible to display one same signal through a vertical amplifier plugin in one bay, and a spectrum analyzer plugin in the other bay.

- Tektronix 519

This one is unlike any other 500-series scope. It is a blazing fast 1GHz analog oscilloscope made in the early 60's... No vertical amplifier, the signal goes straight to the delay line and the deflection plates of the CRT. Is uses special connectors and has a 125-ohm input impedence. This is definately not the every-day use test equipment, but it is definately an awesome collection piece!

- Tektronix 515A / 516

There is nothing incredible about these two, but those are nice smaller oscilloscope models that still makes use of big 5" CRTs. They both have a 15MHz bandwidth which is plenty enough for a lot of projects, if using them on a regular basis and not only for the collection. I'd say it would be a smaller version of the 533, or something close, but without the vertical plugin bay. The 515 is a single trace model with a switch to select between two inputs, and the 516 is a dual trace model. The difference between the 515 and 515A is that the A version has an external Z-axis input and slightly higher sensitity.

And there is the 7k series oscilloscopes which are probably the best of all the analog oscilloscopes with a plugin-style design. Great stuff! No tubes involved here of course, and a lot of proprietary ICs.

Something I'm going to build soon is a fast edge pulse generator that I'll use to measure the rise time of the oscilloscopes I own and determine their maximum bandwidth. There are a few different ways of doing something like that, and one of them is using the avalanche pulse generator design from Jim Williams. I have a Tektronix BNC accessory housing, so I'll see if I can use it for that project.

[tpy]

Great job. This will be fun to watch.

[Martin.M]

- Tektronix 555 (aka "Triple Nickel")

This is a monster... This model is not the fastest dual beam in the 500-series, that would be the 556. But I admire this model with its separate power supply that uses a saturable reactor design to regulate the voltage of all the tube filaments in the entire oscilloscope. It takes not only the two vertical plugins, but also two horizontal timebase plugins. This is probably the most power hungry of all the Tek oscilloscopes with 1kW as far as I remember...

Time to learn a little more 

look in my little community what my friend Matt have done there 
http://www.wellenkino.de/forum/thread.php?board=1&thread=166
That is a living 517A  the biggest baby in the Tek family, and of coarse more hungry then a 555

greetings
Martin

[tggzzz]

I'm not sure whether a purist would count this as a "restoration", but it has certainly returned some old Tek equipment to active service.

I've recently had to debug several scope's 2kV-3kV HV supply and the CRT's Z-axis waveforms at 2.5kV. So far I've got away with using a homemade 1000:1 voltage divider and a multimeter. Since that is crude and not particularly safe, I'm not going to mention the details in order to avoid someone apeing me and hurting themselves.

Then, at a recent auction mentioned elsewhere in this forum, I managed to pick up:

• a 40kV meter for measuring 17kV anode voltages, but which barely registers 2kV
• a Tek P6013A 12kV 1000:1 100kHz scope probe

The probe was functional but missing part of the handle, as shown in the first picture. While not strictly necessary, I wanted to have a little fun fabricating the missing part.

I asked various people at my local Hackspace how they would make a handle, but all the suggested techniques for the large thread seemed tricky and would require buying equipment. Richard Sewell offered the use of his thread gauge to measure the thread, and I eventually decided the easiest, surest, cheapest and fastest way was to 3D print a handle.

Not being sure I would be able to specify the thread sufficiently accurately, I decided to add a lip to the original design, so if the thread was loose I could still jam the body against the lip. It took me a half a day to create the model using OpenSCAD, most of that being taken up with triple checking all the dimensions. The Hackspace's RepRap 3D printer was inadequate for making the thread, but from previous experience I knew that both Shapeway's "strong and flexible" nylon and Dangerous Prototype's SLA materials would work well. The SLA was cheaper (£13 delivered), so I chose that. In the event the handle fitted perfectly, better than I had hoped.

So with a small amount of money, half a day's work (plus some thinking time), and a little help from my friends, I can now debug CRTs less dangerously - and I can eventually sell a working probe for a relatively obscene amount of money

[etienne51]

Time to learn a little more 

look in my little community what my friend Matt have done there 
http://www.wellenkino.de/forum/thread.php?board=1&thread=166
That is a living 517A  the biggest baby in the Tek family, and of coarse more hungry then a 555

Hell... I didn't know this one. Hats off to this fellow for his great restoration! That's one crazy piece of equipment, I haven't noticed that Tek made a 50MHz scope so early.
Thank you for the link.

I'm not sure whether a purist would count this as a "restoration", but it has certainly returned some old Tek equipment to active service.

Great job on that custom part! I'm not sure this could be called a "restoration" considering that some people may call "restoration" the work done to bring an instrument, accessory or anything back to its original state. But that's definately a nice fix you did here!

In fact, a few months back I saw a Tek HV Probe on eBay US for cheap. I'm not sure if it was the same as yours. At that time I didn't really need it and I had other things in mind, so I hesitated. It was sold quite fast as far as I recall.

On my own circuits when I check the Z axis, the whole circuit is floating so I can probe the Z axis relative to the cathode... but NO ONE SHOULD EVER DO THAT since everything that should be at ground potential is then raised at about +2kV (on my circuits).

That's why I should soon get a good probe, I'm going to change the blanking design, and partially replicate what Tektronix did on the 454. To explain briefly, since it's not the topic here, my circuits uses digital blanking right now, through a 2kV-continuous rated optocoupler. The blanking circuit is then working at cathode potential. On the 454, the blanking circuit is working at ground potential, and there is a -2kV offset voltage that is added to the blanking signal. That brings that same signal below cathode potential for the grid. That way, I won't need the optocoupler, and I could get analog blanking working and do a lot more stuff with the CRT. I'm not sure I'll be able to do something as clean and precise as Tektronix did on the 454, but I'll ask my credit card for help the next time I see a good HV probe for sale at a reasonable price, so I can check for issues on my circuit properly.

[tggzzz]

I'm not sure whether a purist would count this as a "restoration", but it has certainly returned some old Tek equipment to active service.

Great job on that custom part! I'm not sure this could be called a "restoration" considering that some people may call "restoration" the work done to bring an instrument, accessory or anything back to its original state. But that's definately a nice fix you did here!

In fact, a few months back I saw a Tek HV Probe on eBay US for cheap. I'm not sure if it was the same as yours. At that time I didn't really need it and I had other things in mind, so I hesitated. It was sold quite fast as far as I recall.

The P6015 is 17kV, but requires occasional refilling with Freon, which is, of course, unobtanium. Without the Freon it is a 13kV probe. The P6015A uses a silicone based replacement.

"Ebay working" probes seem to be £120-£400.

On my own circuits when I check the Z axis, the whole circuit is floating so I can probe the Z axis relative to the cathode... but NO ONE SHOULD EVER DO THAT since everything that should be at ground potential is then raised at about +2kV (on my circuits).

That's why I should soon get a good probe, I'm going to change the blanking design, and partially replicate what Tektronix did on the 454. To explain briefly, since it's not the topic here, my circuits uses digital blanking right now, through a 2kV-continuous rated optocoupler. The blanking circuit is then working at cathode potential. On the 454, the blanking circuit is working at ground potential, and there is a -2kV offset voltage that is added to the blanking signal. That brings that same signal below cathode potential for the grid. That way, I won't need the optocoupler, and I could get analog blanking working and do a lot more stuff with the CRT. I'm not sure I'll be able to do something as clean and precise as Tektronix did on the 454, but I'll ask my credit card for help the next time I see a good HV probe for sale at a reasonable price, so I can check for issues on my circuit properly.

They use similar circuits on many scopes. The DC restorer components are a traditional failure point. You can use a handheld multimeter to check the Z-axis waveform has been succesfully translated to -2kV, but I wouldn't hold the multimeter ro probes while doing it!

The Tek 1502 has a simple HV circuit. I find it amusing to consider the voltages on the front panel intensity and focus controls, especially when the scope is designed to be used when very wet!

[HighVoltage]

The P6015 is 17kV, but requires occasional refilling with Freon, which is, of course, unobtanium. Without the Freon it is a 13kV probe. The P6015A uses a silicone based replacement.

"Ebay working" probes seem to be £120-£400.

I just obtained an original P6015, still filled with Freon and an extra bottle of Freon
The peak voltage rating of the P6015 was higher than the new silicone gel filled P6015A
The biggest problem: The P6015 could be repaired (as long as you had some Freon) but the
P6015A will break because of the silicone gel, when attempted to take apart.

I still have a body of a P6014 (short like P6013) and an original P6013/14 handle that I don't need anymore.
If anyone should be in need of these parts let me know.
@tggzzz may be you want an option to have an original handle as well, let me know

 

[tggzzz]

I just obtained an original P6015, still filled with Freon and an extra bottle of Freon

Blimey, twice over! Firstly that it is still "filled" with Freon (I believe you only need 1mm fluid, plus the Freon vapour above it), and secondly that there's still some in the extra bottle. On second thoughts, perhaps the second is because of the first

I still have a body of a P6014 (short like P6013) and an original P6013/14 handle that I don't need anymore.
If anyone should be in need of these parts let me know.
@tggzzz may be you want an option to have an original handle as well, let me know

Thanks for the kind offer, but I'm not desparate to get an authentic handle. Hence I suspect it is worth more (in both senses) to someone else.

OTOH, please do let me know before you throw them in the bin!