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On Mar 3, 2018, at 12:14, David C. Partridge <david.partridge@...> wrote:

Though you can make a levelling head... See:

< >

Cheers
Dave Partridge

-----Original Message-----
From: [email protected] [mailto:[email protected]] On Behalf Of Dave Daniel
Sent: 03 March 2018 18:23
To: [email protected]
Subject: Re: [TekScopes] What calibration items to buy.

If you do buy an SG-540, make sure that it comes with the leveling head. If it doesn’t, you’ll have to buy or build one. The generator is not much use without the head.

DaveD

Sent from a small flat thingy

On Mar 3, 2018, at 11:06, Brian Bloom via Groups.Io <analogaddict013@...> wrote:

As far as I know, the PG506 calibration generator and SG504 leveled
sinewave generator would be the ideal choice. They're compact and serve many of the purposes. The SG504 has a level output up to 1050Mhz while the SG503 only goes to 250Mhz. I'm not sure what else may be out there that is in the $500.00 USD or less range, but those are the units that I also want, but don't actually need.

I'm currently equipped with what is recommended by the 485 manual, but those two plugins can handle the jobs of a shelf worth of the original manual specified calibration gear, so I'd most definitely try to find those plugins instead.

Also, my knowledge of calibration equipment doesn't extend beyond Tektronix made gear, so there's most likely other options out there as well.

-Brian

As far as I know, the PG506 calibration generator and SG504 leveled
sinewave generator would be the ideal choice. They're compact and serve

I'm currently equipped with what is recommended by the 485 manual, but

Also, my knowledge of calibration equipment doesn't extend beyond Tektronix

-Brian

On Mar 3, 2018, at 11:06, Brian Bloom via Groups.Io <analogaddict013@...> wrote:

As far as I know, the PG506 calibration generator and SG504 leveled
sinewave generator would be the ideal choice. They're compact and serve many of the purposes. The SG504 has a level output up to 1050Mhz while the SG503 only goes to 250Mhz. I'm not sure what else may be out there that is in the $500.00 USD or less range, but those are the units that I also want, but don't actually need.

I'm currently equipped with what is recommended by the 485 manual, but those two plugins can handle the jobs of a shelf worth of the original manual specified calibration gear, so I'd most definitely try to find those plugins instead.

Also, my knowledge of calibration equipment doesn't extend beyond Tektronix made gear, so there's most likely other options out there as well.

-Brian

I thought linearity is good in the extremes of the 10x10 useful area of
the 570, achieved by trading off other CRT parameters not required for a
CT equipment (but usually required for a scope).

Of course, I may be wrong; would like to know more about this noticeable
difference between the CT tubes and contemporary scope tubes, with maximum
vertical scan typically being 6 cm.

Yet another discrepancy is the acceleration voltage: 4kV mentioned in
descriptions like Keller's article, and 6kV in this datasheet.
The 570 schematics shows 4kV.
This datasheet also lacks all the phosphor options we see in previously
mentioned websites (including P31, the standard for the '570).

Sebastian.


Chuck Harris wrote:

It could be as simple as the linear viewing area is 8x10cm,
and the outer 1cm are a touch nonlinear, but still can be viewed.

-Chuck Harris

Sebastian Garcia wrote:

In fact I see that VintageTek site is hosting Keller's article "Tek
CRT
History".



There (part 3) it confirms that the type 570 CT uses a T52 CRT, also
coded
as 5CAP.

Still, the available 5CAP1 datasheet is about a CRT with 8 cm useful
vertical scan.

Any comment will be appreciated, as I may be missing something.

Sebastian.

On Mar 3, 2018, at 11:06, Brian Bloom via Groups.Io <analogaddict013@...> wrote:

As far as I know, the PG506 calibration generator and SG504 leveled sinewave generator would be the ideal choice. They're compact and serve many of the purposes. The SG504 has a level output up to 1050Mhz while the SG503 only
goes to 250Mhz. I'm not sure what else may be out there that is in the $500.00 USD or less range, but those are the units that I also want, but don't actually need.

I'm currently equipped with what is recommended by the 485 manual, but those two plugins can handle the jobs of a shelf worth of the original manual specified calibration gear, so I'd most definitely try to find those plugins instead.

Also, my knowledge of calibration equipment doesn't extend beyond Tektronix made gear, so there's most likely other options out there as well.

-Brian

Dave, if you want to roll your own get a copy of 'Electronics and
Wireless World"
DEC 2001 from yr local library. Page 922 has article 'Differential-in
100Mhz scope probe"
by Cyril Bateman. PC boards would not be available from him now, but
his fully specified circuit and construction methods
should help you achieve your aim. and be easily down gradable to your
target of 20MHz bandwidth with lower spec'd IC's
Some Specs are :

CMR : < 10Mhz >80dB>,70dB at 10MHz, 49dB at 120MHz (Ref 1V input and
10:1 attenuation set)

MAX4005 used inside the probes,MAX 4144 and MAX4107 used inside the
direct input to scope
box. Copper pipe used for probe bodies.
Its also easy to calibrate and adjust. Cyril is (was?) a professional
design engineer and a consultant
on capacitor design. He produced quite a few bits of pro spec'd test
instrumentation in E&WW and his Cap esr tester is
likely to have been (and still be ) the most accurate esr meter so far
ever designed for both enthusiast and semi pro work
I considered getting his PC boards at the time, but got myself a TEK
P6046 and amplifier unit which both worked and were in spec
(If you are thinking of buying these be aware that not many are now in
fully specified or even in working condition)

John




.

I'd recommend just using almost any analog scope that has X-Y capability for display. For low frequencies including audio, the response of the V and H should be virtually identical - you can easily check to be sure. Scaling is no big deal, and can be set up with the scope's range, variable, and position controls to whatever is needed. Even if not, a simple interface circuit should do the trick. You can also use a DSO if it has X-Y, to record very slow or single-shot experiments. Or, an analog storage scope.

I've always had a soft spot for analog computers. Years ago, I had planned to build one, with lots of the usual function elements, and also some digital (kind of cheating) enhancements like A/D-EPROM-D/A operators for non-linear and arbitrary functions. The problem was that there were so many possible options that my tendency to overdo things would have made it a mind-boggling, complicated mess of functions and interconnect issues. So I never did it, but it's fun to think about.

Until this discussion came up, I had no idea that analog computers are still so popular in some circles - looking online a little now, I see that they are alive and well to some extent, even though PCs and SW can do all that and more. There's something to be said for the real thing, hands-on experience.

BTW, I stumbled upon a manual for the GP-6, that appears to include all the circuit schematics. If you haven't found this already, here it is:


Good luck,
Ed