Cable capacitance: a small demonstration of the effects
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5 سال پیش
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A small video about the
A small video about the so called “cable capacitance”.
Everywhere where copper or metal cables with 2 or more wires inside (be it the “mantle” and the central wire, say: coax cable) are used to transport signals (be it audio or HF) there is “cable capacitance” that presses down e.g. possibilities to transport audio frequencies over (very) long wires, say: 20 KHz-500 KHz, say over kilometers of 2 pole wires.
Or: even a 1 pole wire, when the other signal transport wire is immersed in the “ground”, so “the earth” is used as "wire", shows that property.
Such a solution (1 wire earthed) also has a cable capacitance that influences its performance.
But of course the “cable capacitance problem” was already properly solved in the 1950’s by cable (telephone) companies like General Electric (US) and others, and also by Philips (Netherlands) with their sophisticated systems of “line telephony,” where hundreds of telephone users could use only one telephone line, by the use of “pupin” coils, electronic circuits that “fractioned” (in a circular way=switched in a sequence) the line use via (say) a 50 KHz mode, using line amplifiers etc.
This video only demonstrates the effect of cable capacitance. Everyone can conclude what kind of effects this capacitance can have.
In general: for audio and telephone applications a damping of the high frequencies in the audio band (say: 10 KHz – 20 KHz).
By the way: the issue of coax cables in HF applications (radio transmitters and radio receivers) is an essential other issue, not discussed here.
I don’t know much about the use of coax cables, apart of the things that everyone knows: how to use and apply them and split them with the help of resistors to TV receivers, SAT receivers, in a household etc, keeping their impedance (often) on “75 Ohm”.
This video (thus) is only about (stray) capacitance between 2 electrodes in a wire.
All the videos hat I have published on You Tube can be found via my Channel Trailer: Link is
Radiofun232 on YouTube (updated monthly)
In thematic order you can find these video’s under the “comments” section.
Important: to find all the links to the (+/-700) video’s on my YT Channel, select, in the comments section, “NEWEST FIRST”
My books about electronics are available via the website from “Lulu”, search for author “Ko Tilman” there.
https://www.lulu.com/shop/search.ep?k...
There is an important video via which you can buy a document where I give links to many of my video’s, published between 2010 and 2018.
Link is: Radiofun232: Links to my You Tube vid...
My books are also available via Barnes and Noble and via Amazon.
Regarding all my video’s: I constantly keep them actual, so the original video’s with the most recent information are always on YouTube. That is the source, and search there. When my video’s are reproduced or re-edited on other websites/channels you can not (!) be sure about the original content (=really working electronics) and important adaptations to the circuits.
Be aware of that, I saw on the internet my circuits reproduced in a poor or even not proper way. I can not help that, sorry. Upload 6 July 2019.
Oscillating audio amplifiers on long wiring to loudspeakers?
Buy/read my books about how to avoid that or do a search on my YT videos.
Everywhere where copper or metal cables with 2 or more wires inside (be it the “mantle” and the central wire, say: coax cable) are used to transport signals (be it audio or HF) there is “cable capacitance” that presses down e.g. possibilities to transport audio frequencies over (very) long wires, say: 20 KHz-500 KHz, say over kilometers of 2 pole wires.
Or: even a 1 pole wire, when the other signal transport wire is immersed in the “ground”, so “the earth” is used as "wire", shows that property.
Such a solution (1 wire earthed) also has a cable capacitance that influences its performance.
But of course the “cable capacitance problem” was already properly solved in the 1950’s by cable (telephone) companies like General Electric (US) and others, and also by Philips (Netherlands) with their sophisticated systems of “line telephony,” where hundreds of telephone users could use only one telephone line, by the use of “pupin” coils, electronic circuits that “fractioned” (in a circular way=switched in a sequence) the line use via (say) a 50 KHz mode, using line amplifiers etc.
This video only demonstrates the effect of cable capacitance. Everyone can conclude what kind of effects this capacitance can have.
In general: for audio and telephone applications a damping of the high frequencies in the audio band (say: 10 KHz – 20 KHz).
By the way: the issue of coax cables in HF applications (radio transmitters and radio receivers) is an essential other issue, not discussed here.
I don’t know much about the use of coax cables, apart of the things that everyone knows: how to use and apply them and split them with the help of resistors to TV receivers, SAT receivers, in a household etc, keeping their impedance (often) on “75 Ohm”.
This video (thus) is only about (stray) capacitance between 2 electrodes in a wire.
All the videos hat I have published on You Tube can be found via my Channel Trailer: Link is
Radiofun232 on YouTube (updated monthly)
In thematic order you can find these video’s under the “comments” section.
Important: to find all the links to the (+/-700) video’s on my YT Channel, select, in the comments section, “NEWEST FIRST”
My books about electronics are available via the website from “Lulu”, search for author “Ko Tilman” there.
https://www.lulu.com/shop/search.ep?k...
There is an important video via which you can buy a document where I give links to many of my video’s, published between 2010 and 2018.
Link is: Radiofun232: Links to my You Tube vid...
My books are also available via Barnes and Noble and via Amazon.
Regarding all my video’s: I constantly keep them actual, so the original video’s with the most recent information are always on YouTube. That is the source, and search there. When my video’s are reproduced or re-edited on other websites/channels you can not (!) be sure about the original content (=really working electronics) and important adaptations to the circuits.
Be aware of that, I saw on the internet my circuits reproduced in a poor or even not proper way. I can not help that, sorry. Upload 6 July 2019.
Oscillating audio amplifiers on long wiring to loudspeakers?
Buy/read my books about how to avoid that or do a search on my YT videos.
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