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535 calibration

j case
 

Greetings Everyone!

I've been reading the calibration procedure for the 535. One of the
first pieces of equipment mentioned in the procedure is a "ep53a gain
set adapter" for setting the vertical gain. What does the adapter
consist of? Can it be duplicated?

The next piece of special equipment mentioned is a square wave
generator, producing square waves with "whose risetime is faster than
the response time of the type 531 which is about .035 microseconds
with thw type 53/54a preamp in place". The type 104 and 105 generators
are mentioned. Could a simple circuit with a 555 timer chip (or
something similar) produce square waves this fast? Or maybe should I
be looking at the type 105's on Ebay more seriously?

Any advice would be appreciated.

Thanks,

John

Craig Sawyers
 

AKA 013-0005-00

Take a plug and a socket. Wire from pin to pin except:

Pin 3 to pin 3 - a 220k resistor
Pin 3 of plug to banana socket - two 0.1uF 400V caps in parallel

It enables you to inject a calibrator signal into one half of the vertical
amp of the mainframe, to normalize the gain.

I made one up, and promptly found a fault in my 545A (R1017 open). I then
bought one on eBay for not very much at all.

Craig

-----Original Message-----
From: TekScopes@... [mailto:TekScopes@...]On
Behalf Of casej451
Sent: 20 September 2005 05:00
To: TekScopes@...
Subject: [TekScopes] 535 calibration


Greetings Everyone!

I've been reading the calibration procedure for the 535. One of the
first pieces of equipment mentioned in the procedure is a "ep53a gain
set adapter" for setting the vertical gain. What does the adapter
consist of? Can it be duplicated?

The next piece of special equipment mentioned is a square wave
generator, producing square waves with "whose risetime is faster than
the response time of the type 531 which is about .035 microseconds
with thw type 53/54a preamp in place". The type 104 and 105 generators
are mentioned. Could a simple circuit with a 555 timer chip (or
something similar) produce square waves this fast? Or maybe should I
be looking at the type 105's on Ebay more seriously?

Any advice would be appreciated.

Thanks,

John






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Craig Sawyers
 

The next piece of special equipment mentioned is a square wave
generator, producing square waves with "whose risetime is faster than
the response time of the type 531 which is about .035 microseconds
with thw type 53/54a preamp in place". The type 104 and 105 generators
are mentioned. Could a simple circuit with a 555 timer chip (or
something similar) produce square waves this fast? Or maybe should I
be looking at the type 105's on Ebay more seriously?
If you're looking for something like this, go for the 106. It is a whole
lot lighter and smaller than the 105, essentially replaced it, and is of
better general utility.

It was also specified for setting 7xxx series scopes and plug-ins too until
it was replaced by the PG506. This is much more expensive, and isn't at all
necessary for setting up a 5xx.

Craig

Larry Christopher
 

Hi John,

You can do this if you have a male and female amphenol connectors
from salvaged equipment or purchased new. The part numbers you need
are 26-190-16 (female) and 26-159-16 (male). As Craig says, you wire
all pins one-for-one except pin 3. In place of a straight wire, you
wire a 220K resistor from pin 3 male to pin 3 female.

Now, from the MALE end to the bananna jack, Tektronix uses two .1 mfd
capacitors in parallel. They do this so the caps will fit in the
housing, so you could use other values. They wire the two caps in
parallel, and they go from pin 3 of the MALE to the bananna jack.

In order to use this, you feed 400mv from the calibrator to the
bananna jack, which is then injected into pin 3 of the scope via the
caps. This allows you to set the gain of the vertical amplifier to
the correct value, 100mv/cm. You would then calibrate your preamps.

The main reason you would do this is if you have more than one
mainframe, and you want to interchange your plugins among scopes
without recalibrating them. If you only have one scope, you can set
the gain on the plugin itself, and they will all work ok.

Larry Christopher

--- In TekScopes@..., "casej451" <casej451@y...> wrote:
Greetings Everyone!

I've been reading the calibration procedure for the 535. One of the
first pieces of equipment mentioned in the procedure is a "ep53a gain
set adapter" for setting the vertical gain. What does the adapter
consist of? Can it be duplicated?

The next piece of special equipment mentioned is a square wave
generator, producing square waves with "whose risetime is faster than
the response time of the type 531 which is about .035 microseconds
with thw type 53/54a preamp in place". The type 104 and 105 generators
are mentioned. Could a simple circuit with a 555 timer chip (or
something similar) produce square waves this fast? Or maybe should I
be looking at the type 105's on Ebay more seriously?

Any advice would be appreciated.

Thanks,

John

Larry Christopher
 

I forgot to mention, you could certainly jury rig this if you don't
want to make up an adapter or if you have no connectors. Just unsolder
the wire on pin 3 in a plugin. Insert it into the scope, then remove
the laft side panel. Turn the scope on its right side (plugin up) and
remove the bottom panel. Solder a 220K resistor from the wire you
removed to pin 3. Also solder the capacitor to pin 3 on the plugin
connector.

Now you can feed the calibrator to the free end of the capacitor and
calibrate. Don't let anything short, pin 3 has 67 volts on it so be a
bit careful. After you are done setting the gain, put everything back
the way it was.

Larry Christopher

--- In TekScopes@..., "Larry Christopher" <tektronix@t...>
wrote:
Hi John,

You can do this if you have a male and female amphenol connectors
from salvaged equipment or purchased new. The part numbers you need
are 26-190-16 (female) and 26-159-16 (male). As Craig says, you wire