[volt-nuts] Tek gear

Chuck Harris cfharris at erols.com
Fri Nov 19 14:53:23 UTC 2010

The thing is Dick's recollection, although flippant, and fun, isn't
entirely true.  Yes, Tektronix had a ceramics facility that was
under utilized, but they weren't above getting rid of it wholesale.
(Which ultimately they did.)

It required a tremendous amount of retooling to make ceramic CRT's.
Nothing from the facility that made barrier strips could fit the bill.
The hydraulic presses were too small to handle the large jug molds.
The kilns were too small to fire a significant quantity of jugs.
The ball mills were too small to grind up enough ceramic, the building
was too small to handle the new larger machines... need I say more?

The reason ceramic jugs were made is because glass wasn't economically
suited to flat screen CRT's, and complicated storage CRT's.  Oh, and
there was another reason, Corning was too expensive at the level of
quality needed for the flat screen CRT's and complicated storage CRT's.

If you want to see more of the history, check out:


The whole ceramic vs glass crt situation is explained in detail...by
the guys who did the work, and made the decisions.

This is my last word on the subject.  This is a little far afield for

-Chuck Harris

Marvin E. Gozum wrote:
> Thanks Dick, those historical tidbits are priceless.
> Ceramics vs glass: That's funny, but they must have been very good at it
> given the qualities of these material.
> Tuning Tek vs clone analog scopes: shows why much high end gear, even in
> today's digital world, are like musical instruments. Its easy to make
> any instrument look like a piano, but the tuning or subtleness in
> material and workmanship, makes all the difference.
> I am awaiting a Chinese clone of the 25 year old design of the HP 3458a,
> does anyone know?
> There is a very active group in reverse engineering, say China. But in
> many high end things, their folks reach a brick wall, but until that
> happens, it seems like their growth rate is enough to run through us.
> Solution? Pour into US/EU engineering schools to get the answer.
> At 05:37 PM 11/18/2010, Dick Moore wrote:
>> On Nov 18, 2010, at 4:00 AM, volt-nuts-request at febo.com wrote:
>> > Message: 2
>> > Date: Wed, 17 Nov 2010 15:07:35 -0500
>> > From: "Marv Gozum @ JHN" <marvin.gozum at jefferson.edu>
>> > Subject: Re: [volt-nuts] Keithley - and Tek gear
>> >
>> > Thanks Dick, that's priceless insight.
>> >
>> > Can you explain the benefit of the ceramic jug over just plain glass?
>> >
>> >
>> Marv, there was no advantage to the ceramic jugs at all, quite the
>> contrary -- it's just that Tek had a very sizable and expensive
>> building devoted to making ceramics, and it wasn't going to be used
>> any more -- what to do with it? "I know, we'll make ceramic CRTs!!!"
>> > ------------------------------
>> >
>> > Message: 3
>> > Date: Wed, 17 Nov 2010 15:59:59 -0500
>> > From: Chuck Harris <cfharris at erols.com>
>> > Subject: Re: [volt-nuts] Keithley - and Tek gear
>> > To: Discussion of precise voltage measurement <volt-nuts at febo.com>
>> > Message-ID: <4CE4424F.40006 at erols.com>
>> > Content-Type: text/plain; charset=UTF-8; format=flowed
>> >
>> > Dick Moore wrote:
>> >
>> >> It was a little more complicated -- When I started at Tek in 1961,
>> I was told that in the 50's, during the Korean
>> >> conflict, Tek had military contracts that stipulated that Tek had
>> to allow other firms to build the mil-spec gear as
>> >> a matter of national security. Lavoie Labs and Dumont built Tek
>> scopes under these contracts, and then continued to
>> >> build Tek scope clones for years afterward, on into the 60's, most
>> notably, clones of the 530 and 540 series, which
>> >> had mil contract provisions on them. Tek of course had the ceramic
>> terminal strips and the others didn't -- Tek made
>> >> those ceramic strips themselves.
>> >
>> > To quote Stan Griffiths:
>> >
>> > " Counterfeit Instruments
>> > ------------------------
>> >
>> > During the late 50's, and early 60's, at least three different
>> > companies produced copies of popular Tektronix oscilloscopes.
>> > These instruments were sold to the U.S. Military under large
>> > contracts and show up occasionally in the surplus market today.
>> > If you are not aware of this situation, you could easily buy
>> > one of these bogus instruments thinking it was manufactured by
>> > Tektronix because their appearance is so similar to the real
>> > thing. These copies provoked a 20-year-long lawsuit for patent
>> > infringement against the Federal Government that Tektronix
>> > eventually won."
>> >
>> > - Oscilloscopes Selecting and Restoring a Classic,
>> > by Stan Griffiths - ISBN: 0-9633071-5-0, p37.
>> > (Apparently self published)
>> >
>> > He goes on to say the companies are Hickok, Jetronics, and Lavoie.
>> >
>> > As an additional point, my dad, a life time DOD engineer, once told me
>> > that Tektronix refused to make milspec scopes, in the 50's and 60's,
>> > because they didn't want to get tied into the government contracting
>> > requirements, second sources being among them. All tek scopes, during
>> > that time frame, were bought off the shelf.
>> >
>> > The Hickok, Jetronics, and Lavoie scopes were entirely made at the
>> > government's request to fulfill their need for control. They basically
>> > told the companies not to worry about the patents, the US would take
>> > care of it.
>> >
>> > -Chuck Harris
>> Thanks Chuck for the note. It's true that Tek didn't build to
>> mil-spec, and that their government sales were off-the-shelf product,
>> although, the 647 was supposedly a "ruggedized" scope which was, so I
>> was told, aimed at military sales, though not as a mil-spec unit.
>> I only actually touched one clone, which was, as I remember, a 535 (or
>> maybe a 531) from Lavoie. It was a pretty good copy, but the word was
>> that they had reliability problems. I was also told that the clone
>> makers all had problems making and tuning the distributed delay lines,
>> which resulted in crappy risetime, overshoot/undershoot, and generally
>> poor pulse fidelity. Tuning those lines was a real art, and only a few
>> guys in Final Test could do it well.
>> I heard that Hickok made some clones, but I only heard that as a
>> rumor, same way I heard that Dumont was making them. I never heard
>> about Jetronics at all. But I was a grunt in those days -- very low
>> level employee, just starting my working life.
>> Dick Moore
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> Sincerely,
> Marv Gozum
> Philadelphia, PA
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