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<p>Hi Paul,</p>
<p>I doubt you will be able to measure this directly, especially over a meter or two of cable. And 1m cables don't act as transmission lines until the signals are well in the MHz range.</p>
<p>Assuming a 300 ohm source impedence, and 100pF cable capacitance, the -3db frequency is around 5 MHz.</p>
<p>(Rough numbers from <a href="https://www.diyaudio.com/forums/parts/285128-measuring-capacitance-rca-cables.html">https://www.diyaudio.com/forums/parts/285128-measuring-capacitance-rca-cables.html</a> )</p>
<p>However, I can either lend or you can come around and use my Analogue Discovery 2. It has a Vector Network Analyzer function. that injects a test signal and lets you measure gain and phase of the thing under test. https://reference.digilentinc.com/learn/instrumentation/tutorials/waveforms-network-analyzer/start</p>
<p>If you want, I can get something like <a href="https://www.jaycar.co.nz/2-way-phenolic-rca-socket/p/PS0263">https://www.jaycar.co.nz/2-way-phenolic-rca-socket/p/PS0263</a> to make up a test jig ( 300 ohm source resistor, 10kOhm load resistor, test points).</p>
<p>I just worry that getting a "no result" is very uninspiring, and we all expect that pretty much all RCA cables are much like each other.</p>
<p>Mike.</p>
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<p>On 08.09.2020 09:38, Paul Willmott-Dalton wrote:</p>
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<div dir="auto">Hello all
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<div dir="auto">I am trying to support my 14yo boy with his homework but am a bit out of my depth. He is aiming to demonstrate understanding of the scientific method. To do this he wants to make a comparison of the electrical properties of different brands of audio cables. His hypothesis is that there is no difference between 'audiophile' cables vs cheapies.</div>
<div dir="auto"> </div>
<div dir="auto">I under that folks talk about capacitance being a variable. I'm told that this will be very small in any cable and potentially difficult to read (in the tens of pF range).</div>
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<div dir="auto">Does anyone out there have the equipment necessary to do this? If so, could we bring some cables to you for testing?</div>
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<div dir="auto">Kind regards</div>
<div dir="auto">Paul Willmott Dalton</div>
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