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Oscilloscope for ham radio work

Discussion in 'General Technical Questions and Answers' started by KB3PXR, Jan 2, 2008.

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  1. VK6ZGO

    VK6ZGO Ham Member QRZ Page

    Get the best Oscilloscope (CRO) you can get,but any Oscilloscope is better than nothing.
    Most of the time you don't need to have absolute amplitude accuracy,so a 10MHz device will usually still give a usable display at up to 30MHz.

    A 10MHz CRO will show you 2nd harmonic distortion on a 80m signal OK.
    Most times you will just be looking at the signal to see if it's there.
    Also a lot of your work will be looking at DC signals.After you get used to a CRO,you will be amazed at how versatile they are.

    In most of my fault finding I hardly touch my DMM,as the CRO allows me to simultaneusly get a fair check on the DC levels & also see if there are any extraneous signals on the test point.

    At the moment I have a "cheapie" Chinese 10MHz CRO,& a 40MHz BWD (the BWD has triggering problems).One day I'll get around to having a look at the faulty one using the good one.

    More important than wide bandwidth in the better units are such things as multiple channels,delayed timebase & (very seldom mentioned),access to the vertical amplifier  output.(Not the deflection plate signal,but a  50 or 75 ohm output).This can be used as an adjustable preamp to lift signals to a usable level for various test & experimental setups)

    Be very afraid of older DSO's,as they change their sample rate depending on their timebase setting. For instance,if you try to look at a NTSC or PAL analog video signal at field rate,the sample rate is not high enough to reproduce the line information,& the display is unusable.

    They are usually reasonable if displaying a single line of video,although the colour burst is displayed with a lot fewer cycles than it really has.

    The same applies to looking at AM modulation envelopes, as the sample rate is appropriate for the AF modulating signal.

    73 VK6ZGO
     
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