Re: Measuring Phase Response

In article <g30295$1ibf$1@xxxxxxxxxxxxxxxxx>,
Ian Thompson-Bell <ruffrecords@xxxxxxxxxxx> wrote:

Phil Allison wrote:
"Ian Thompson-Bell"
It is relatively straightforward to measure the amplitude response of an
amplifier, but what about measuring the phase response without expensive
test equipment. I had thought of using Lissajous figures on a 'scope but
are there any more direct but still low cost methods?

** No dual trace scope available ?


Yes I have one, and it has an X-Y mode so Lissajous is a possibility. I
have never used them so I have no idea how accurate they can be and the
resolution that can be achieved - or did you have something else in mind?


** All you do is superimpose the test sine wave and the output sine wave &
synch the time base to the test wave.

By inspecting successive zero crossings, the phase offset is easily
determined at any given frequency.

Doh! Of course! Strange how the obvious eludes me.

A simple instrument can be built with a couple of comparator chips, and
a few logic gates, that will indicate phase on a meter.


Regards,

John Byrns

--
Surf my web pages at, http://fmamradios.com/
.

Relevant Pages

  • Re: Measuring Phase Response
    ... but what about measuring the phase response without expensive ... I had thought of using Lissajous figures on a 'scope but ... ** No dual trace scope available? ... ** All you do is superimpose the test sine wave and the output sine wave & ...
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  • Re: Measuring Phase Response
    ... but what about measuring the phase response without expensive ... I had thought of using Lissajous figures on a 'scope but ... ** No dual trace scope available? ... ** All you do is superimpose the test sine wave and the output sine wave & ...
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  • Re: Measuring Phase Response
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