Author Topic: philips pm3230 oscilloscope test  (Read 1725 times)

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Offline davy pelemanTopic starter

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philips pm3230 oscilloscope test
« on: January 10, 2018, 02:49:19 pm »
i just purchased an old scope and i wanted to test it. so i took a little oscillator circuit i had laying around. it runs at 30 hz  and is powered with a small transformer (fully rectified and a 4700uf cap). now the signal has a lot of hum (60 cycle from the line). when i touch the positive probe and the transformer the hum is gone and i see an nice clean square wave. can someboby explain what is happening. should i ground the transformer? the scope could also use some new electrolitics, but still waiting on the order.

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