[Test-Equipment] Fw: Tektronix 465 question

[W1GOR]

Bill,

Are you SURE that the calibrator signal is correct..?  It would be prudent 
to confirm the accuracy of the calibrator before changing the gain of either 
vertical channel.  Also, confirm the proper operation of each probe. 
Connect a direct cable, in place of a probe, between channel A and the 
calibrator, after confirming it's accuracy.   Then connect channel B to the 
calibrator.

You can also use a common AAA, AA, C, or D cell to check the calibration of 
each channel, you should see a deflection of approximately 1.5 volts, which 
should 'get-you-in-the-ballpark'...   Try this with each channel directly 
and with each probe.  The difference between direct and through-the-probe 
will be the attenuation factor of the probe, typically 1:1, 10:1, or 50:1. 
Look at the information specified on each probe to determine the attenuation 
factor.  Lastly, do not forget to 'compensate' each probe with a 
fast-risetime squarewave to minimize undershoot and overshoot.  Properly 
adjusted, the waveform should be a very clean risetime, flat topped, pulse 
or squarewave.  Compensation cannot be properly adjusted with a sine wave... 
You will need a sharp, clean square wave to properly compensate the probes.

73, Larry - W1GOR




----- Original Message ----- 
From: "Bill Smith" <hbcs at sonic.net>
To: <test-equipment at mailman.qth.net>
Sent: Sunday, August 21, 2005 12:50 AM
Subject: [Test-Equipment] Fw: Tektronix 465 question


> Have just acquired a 465 oscilloscope in beautiful condition.  However, 
> both
> channels are out of calibration and read about 150% high when connected to
> the calibration bar.  Have the book but have not opened the cabinet, yet.
> Wonder if anyone has run across this problem and can give me a hint where 
> to
> start looking.
>
> 73 de Bill, AB6MT
> ab6mt at sonic.net
>
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