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Calibration units for telequipment D75 or D83 (Tek D755)

D

David C. Partridge

The calibration instructions call for two "calibration units" Tektronix part
numbers 067-672-00(vertical) and 067-673-00(horizontal), which for sure are
highly unlikely to be available anywhere 30 years after the fact.

From the instructions, it is my GUESS that the horizontal unit routes the
input from its front panel to direct to the main X amp input, and MAY also
generate an unblanking signal (based maybe on its input).

Similarly my guess for the vertical cal unit suggests that when the "BAL"
function is selected then the inputs to the Y amp are referenced to ground
via a resistor network or possibly just connected together (possibly via a
lowish value resistor) and when "CAL" is selected the front panel input is
fed directly to the Y amp input (pins 5 and 13 on the output pcb connector).

That's all on the assumption that these units are pretty much passive - all
bets are off if they are active things.

Does anyone actually know what they do? Or even have these plug-ins or the
schematics for them?
 
N

N Cook

David C. Partridge said:
The calibration instructions call for two "calibration units" Tektronix part
numbers 067-672-00(vertical) and 067-673-00(horizontal), which for sure are
highly unlikely to be available anywhere 30 years after the fact.

From the instructions, it is my GUESS that the horizontal unit routes the
input from its front panel to direct to the main X amp input, and MAY also
generate an unblanking signal (based maybe on its input).

Similarly my guess for the vertical cal unit suggests that when the "BAL"
function is selected then the inputs to the Y amp are referenced to ground
via a resistor network or possibly just connected together (possibly via a
lowish value resistor) and when "CAL" is selected the front panel input is
fed directly to the Y amp input (pins 5 and 13 on the output pcb connector).

That's all on the assumption that these units are pretty much passive - all
bets are off if they are active things.

Does anyone actually know what they do? Or even have these plug-ins or the
schematics for them?

Are they aren't just board extenders for working outside of chassis ?
 
D

David C. Partridge

No those are different parts - I could cobble those up readily if I needed
them - in fact you don't need them if your fingers are reasonably agile.

David
 
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