Julian's Collection of Tektronix Oscilloscopes and Plug Ins

The following shows part of my collection. I still need to describe the 7844 dual beam scope, the 7L5 Spectrum Analyser and host 7603 scope,  and several 7000 series plugins and other equipment I've acquired more recently.

Want List

I am interested in acquiring the following:

1) 1A4, M, N, R, T plugins for 500 series scopes 
2) 7D20, 7CT1N, 7D11, 7L12, 7L13, 7L14, 7S14 plugins for 7000 series scopes 
3) THS700 series handheld scopes 

556 Oscilloscope S/N 002341

This scope was being thrown out at Caltech, and I rescued it. It worked perfectly and came complete with an L Plug In, and a 1L5 Spectrum Analyzer Plug In

I downloaded the manual from BAMA. It is available here. Amazingly I subsequently found at Caltech in an old filing cabinet the original manual that came with this 556. This is nice to have. I also found the original scope cart, model 205-2, complete with instructions, that was purchased at the same time. Here's a shot of the 556 on its cart:

The 205-2 instruction manual is available here.

454 Portable

The 454 manual is here.

575 Transistor Curve Tracer S/N 001100

Ebay: $50. This had broken rubber fan mountings, which I managed to repair by first soaking the rubber pieces in olive oil, then boiling them gently in water for a few minutes, followed by careful drying and glueing. Here is the picture from the seller next to a pic of the re-finished 575.

Here's a detail of the fan: you can see how the rubber mounting bushes have detached from the fan assembly. (Note the date on the Fan itself: Nov 18th. 1958.)

The manual for the 575 is here.

Here's a description of using the 575.

Restoring to operation

I rejuvenated the rubber fan mounts by the following method:

• Soak in olive oil for 1/2 hour
• Place in boiling water for 5 minutes
• Thoroughly dry and clean
• Re-attach metal mounting plates using super glue.

The rubber felt like new after this process.

After powering up the 575, I was able to get good curves from a test transistor. However, shortly afterwards, when re-powering the machine, the trace had become very dim, and I could not adjust it with the Intensity control properly. I thus embarked on a long-winded dialogue with the experts in the Yahoo! Tekscopes discussion group. See http://groups.yahoo.com/group/TekScopes/message/16367

It turned out that the cathode had somehow become disconnected inside the CRT. I obtained a replacement CRT together with a whole bunch of other 575 spare parts from Ed, who dismantled his unwanted 575 for me.

The next problem was adjusting the Phase A/B to look like the pictures in the manual. Here is what my Phase A trace looked like, at its best:

And here is the page from the manual with a figure showing what it should look like:

After diagnosing this for a while, I became suspicious of the bumble bee capacitors in the Step Generator. You can see them here in the top right hand corner of the photo: they're the large striped components.

One had a hairline crack in it, and I ended up replacing the whole lot with polyesters. This cured the asymmetry.

Here's a gratuitous tube-porn picture of the power supply tubes in the 575:

Refinished cabinet sides

I repainted the 575's cabinet sides, which were looking a bit tatty, in gun metal grey.

Auction prices for 575s

Recent (11/2005 to 01/2006) Ebay sold prices for 575s: $610, $125, $50, $131, $100, $160, $124

Other 575s

(click thumbnails for larger photo):

214 Storage Oscilloscope S/N B301679

From Ebay ... came as part of some weird gas testing system. This is the most beautiful oscilloscope I have: so neat, carefully designed, solid construction and very, very tiny (compare with the wine glass).

Here is the case.

The 214 scope is in superb condition, probably because it has sat in  this padded environment, and been rarely used.

The service manual for the 214 scope is here.

The manual for the 212 (similar) scope is here.

Tektronix 221 Portable Oscilloscope

Now, here's a sorry story. Phil Stewart sent me this 221, which he had picked up on Ebay. It was badly damaged from leaking internal batteries. Here are some pictures. I haven't decided whether it is worth trying to restore this, or not.

Here is one of the boards in a Balsamic Vinegar bath

The schematic for the 221's power supply board is here. (Thanks to David DiGiacomo.)

561A Oscilloscope S/N ?????

Another find near the dumpster at Caltech. Complete with three plug-ins, and also a couple of 1-series plug-ins.

The manual for the 561A is here.

The manual for the 3A6 plug-in is here.

The manual for the 3A3 plug-in early models is here, late models is here.

The manual for the 3B3 plug-in is here.

321A Oscilloscope

From Ebay: the money I spent on this apparently went to Katrina victims.

This scope had some display problems (but a good CRT), and was missing a front panel knob. It is now fully operational.

The 321A manual is here.

5441 Storage Oscilloscope

Another throwout (with two 5A48 and a 5B42 plug in). There was clearly a problem: no trace at all unless I pushed the beam finder button. So I opened it up, and started looking at the vertical amplifier. (Since the display in the beam finder had some lateral extent, I was guessing something wrong with the vertical amp.)

The circuit diagram in the manual downloaded from BAMA (see below for local copy) looked very similar to a 556's vertical amp, to my untrained eye, so I decided to apply the method described to me in this group by Larry, Stan et al a few months ago, which involves connecting the two halves of the differential amplifier chain together, starting near the deflection plates and working backwards. Lo and behold, I could get a trace, and stepping backwards, it remained until I passed Q107. Then it disappeared. Q107 base to emitter measured closed circuit.

Finding the part number (151-0434- 00), www.sphere.bc.ca showed that an equivalent was a 2N4261. Amazingly I had a 2N4261 (and only one) in my parts box. Thus I snipped out the offending transistor, soldered in the replacement, and voila! the trace appeared and everything seems to work! I was so surprised, I almost fell off my stool: it had taken about 20 minutes.

Now all that needs doing is to replace a couple of the knobs from the 5B42 timebase, which are broken. Update: I picked up a new 5B42 timebase at C&K Surplus in Pasadena, for $20.

Stan Griffiths has a very good Tektronix transistor part number converter here.

The manual for the 5441 is here.

The manual for the 5A48 plug in is here.

The manual for the 5B42 plug in is here.

310 Oscilloscope S/N 4455

Ebay: $8. The seller shipped it in a box with five pieces of folded newspaper. Miraculously, the 310 arrived undamaged. Here's a photo before and after cleaning. With this scope I removed all tubes sprayed liberally with Simple Green, then hosed down with a lot of cold water, and let dry in the sun.

Here are some photos of the internals:

310A Oscilloscope S/N 019857

I bought this 'scope on Ebay for $15 simply because it looked so cute, like a scaled down version of the 556 :-)

More details about the 310A and its restoration.

I've collected some pictures of other 310 series 'scopes.

516 Oscilloscope

I bought this 516 on Ebay for $35, including the original Tektronix manual and two Philips x10 probes.

More details on the 516 and its restoration.

My Manuals

I have the following original Tek manuals in my possession.

My Plug Ins

This is just a few of my plugins. From left to right, top to bottom: L, D, 53/54 L, 5B42, L, 53/54 K, K, D, 53/54 G, Z

In 556 (not shown): CA, 1L5

Here's a complete list:

L Plug Ins

I have two L Plug Ins, one which came in the 556, and one which I bought as a spare on Ebay for $20. The pictures from the seller:

The manual for the L Plug In is here (a missing page from this file is here).

CA Plug In

This is a dual channel Plug In. I bought it on Ebay for $15. Here is the picture from the seller:

The manual for the CA Plug In is here.

D Plug In

The D Plug In is a high gain differential pre-amplifier. I bought it on Ebay for $1, without its tubes. Here are the pictures from the seller:

The manual for the D Plug In is here.

53/54G Plug In

Another unit raped of its tubes. This one cost me $4.99. Here are the pictures from the seller:

The manual for the G Plug In is here.

Z Plug In

The Z manual is here.

81 Adapter

The 81 adapter allows the 1-series and letter-series Plug Ins to be used in a 58x series 'scope. The L Plug In I bought on Ebay came with an 81 Adapter, an unexpected bonus.

Various views of the adapter:

Here's a photo of the 81 adapter attached to the L Plug In, as the unit arrived from the Ebay seller:

The manual for the 81 Adapter is here.

Useful Links

A wealth of information at Sphere!

The Tektronix section at BAMA.

Alan Bain's interesting Tek scopes pages.

Click to join TekScopes

The frappr map at http://www.frappr.com/tekscopes