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Old 19th Oct 2017, 10:36 pm   #1
Eichberger
Triode
 
Join Date: Apr 2017
Location: Winchester, Hampshire, UK.
Posts: 42
Default EQ circuit testing

Would anyone be able to interpret the following test results for me?

I am suspicious that there is something wrong with the EQ circuit in my Tandberg 12 so I've been doing a bit of testing with an oscilloscope. I input a 2kHz sine to the inputs and traced it through to the recording head.

There is an initial recording pre-amplifier section which looked fine. I then took a trace at the output of the recording EQ (just before the recording current trim pot) and got the trace attached.

The trace shows a pulse shape. Is this normal or does this show a problem with the EQ circuit? Was it wrong to expect to still see a sign wave?

Any input greatly appreciated.
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