Why did CATV standarize in 75 ohms and everyone else in 50? The Next CEO of Stack OverflowHow is transmission line impedance selected?Industry standard Cat5e cablingWhy Characteristic Impedance must be 50 ohms?Why Inductor reactance 180 ohms?Why do cables have multiple grounds?Where did Bootstrapping get its name?What does S stand for in 75 S ohms?How did wireless telegraphy reach so far?What frequency did wireless telegraphs operate at?Problem understanding CDMA and W-CDMAStandard 2.54/1.27mm pinheader impedance
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Why did CATV standarize in 75 ohms and everyone else in 50?
The Next CEO of Stack OverflowHow is transmission line impedance selected?Industry standard Cat5e cablingWhy Characteristic Impedance must be 50 ohms?Why Inductor reactance 180 ohms?Why do cables have multiple grounds?Where did Bootstrapping get its name?What does S stand for in 75 S ohms?How did wireless telegraphy reach so far?What frequency did wireless telegraphs operate at?Problem understanding CDMA and W-CDMAStandard 2.54/1.27mm pinheader impedance
$begingroup$
All of the CATV industry runs on 75 ohm systems, while most of the rest of the radio world uses 50 ohms.
Why was this standard chosen?
I was wondering this because good quality RG6 cable can be obtained everywhere for very little, compared to decent quality 50 ohm cabling.
impedance cables telecommunications coaxial
asked 7 hours ago
hjfhjf
4942823
$endgroup$
add a comment |
$begingroup$
All of the CATV industry runs on 75 ohm systems, while most of the rest of the radio world uses 50 ohms.
Why was this standard chosen?
I was wondering this because good quality RG6 cable can be obtained everywhere for very little, compared to decent quality 50 ohm cabling.
impedance cables telecommunications coaxial
asked 7 hours ago
hjfhjf
4942823
$endgroup$
$begingroup$
Some insight is in Andy's answer:electronics.stackexchange.com/questions/350451/…
$endgroup$
– glen_geek
7 hours ago
1
$begingroup$
I'm not sure if I should say "a substantial minority" or "enough so that it's known" -- but there are radio amateurs who use 75 ohm transmission line for this reason. If you're going to run an antenna tuner anyway, and if you're going to build your own antennas anyway, then it's not a bad way to get a bit more bang for the buck.
$endgroup$
– TimWescott
7 hours ago
$begingroup$
@TimWescott specifically, this: qsl.net/g4hbt/dipole.htm antenna specifies a 75 ohm line. I finally understand why.
$endgroup$
– hjf
7 hours ago
$begingroup$
It was 75 ohms for RF signals before cable TV was a "thing". I've always figured it was the cable manufacturers, so they could force you to buy two spools of cable instead of just one. And the connector manufacturers, so they could sell you two different sizes of connectors.
$endgroup$
– Hot Licks
6 hours ago
add a comment |
$begingroup$
All of the CATV industry runs on 75 ohm systems, while most of the rest of the radio world uses 50 ohms.
Why was this standard chosen?
I was wondering this because good quality RG6 cable can be obtained everywhere for very little, compared to decent quality 50 ohm cabling.
impedance cables telecommunications coaxial
asked 7 hours ago
hjfhjf
4942823
$endgroup$
All of the CATV industry runs on 75 ohm systems, while most of the rest of the radio world uses 50 ohms.
Why was this standard chosen?
I was wondering this because good quality RG6 cable can be obtained everywhere for very little, compared to decent quality 50 ohm cabling.
impedance cables telecommunications coaxial
impedance cables telecommunications coaxial
asked 7 hours ago
hjfhjf
4942823
asked 7 hours ago
hjfhjf
4942823
asked 7 hours ago
hjfhjf
4942823
asked 7 hours ago
hjfhjf
4942823
asked 7 hours ago
hjfhjf
4942823
4942823
$begingroup$
Some insight is in Andy's answer:electronics.stackexchange.com/questions/350451/…
$endgroup$
– glen_geek
7 hours ago
1
$begingroup$
I'm not sure if I should say "a substantial minority" or "enough so that it's known" -- but there are radio amateurs who use 75 ohm transmission line for this reason. If you're going to run an antenna tuner anyway, and if you're going to build your own antennas anyway, then it's not a bad way to get a bit more bang for the buck.
$endgroup$
– TimWescott
7 hours ago
$begingroup$
@TimWescott specifically, this: qsl.net/g4hbt/dipole.htm antenna specifies a 75 ohm line. I finally understand why.
$endgroup$
– hjf
7 hours ago
$begingroup$
It was 75 ohms for RF signals before cable TV was a "thing". I've always figured it was the cable manufacturers, so they could force you to buy two spools of cable instead of just one. And the connector manufacturers, so they could sell you two different sizes of connectors.
$endgroup$
– Hot Licks
6 hours ago
add a comment |
$begingroup$
Some insight is in Andy's answer:electronics.stackexchange.com/questions/350451/…
$endgroup$
– glen_geek
7 hours ago
1
$begingroup$
I'm not sure if I should say "a substantial minority" or "enough so that it's known" -- but there are radio amateurs who use 75 ohm transmission line for this reason. If you're going to run an antenna tuner anyway, and if you're going to build your own antennas anyway, then it's not a bad way to get a bit more bang for the buck.
$endgroup$
– TimWescott
7 hours ago
$begingroup$
@TimWescott specifically, this: qsl.net/g4hbt/dipole.htm antenna specifies a 75 ohm line. I finally understand why.
$endgroup$
– hjf
7 hours ago
$begingroup$
It was 75 ohms for RF signals before cable TV was a "thing". I've always figured it was the cable manufacturers, so they could force you to buy two spools of cable instead of just one. And the connector manufacturers, so they could sell you two different sizes of connectors.
$endgroup$
– Hot Licks
6 hours ago
$begingroup$
Some insight is in Andy's answer:electronics.stackexchange.com/questions/350451/…
$endgroup$
– glen_geek
7 hours ago
$begingroup$
Some insight is in Andy's answer:electronics.stackexchange.com/questions/350451/…
$endgroup$
– glen_geek
7 hours ago
1
1
$begingroup$
I'm not sure if I should say "a substantial minority" or "enough so that it's known" -- but there are radio amateurs who use 75 ohm transmission line for this reason. If you're going to run an antenna tuner anyway, and if you're going to build your own antennas anyway, then it's not a bad way to get a bit more bang for the buck.
$endgroup$
– TimWescott
7 hours ago
$begingroup$
I'm not sure if I should say "a substantial minority" or "enough so that it's known" -- but there are radio amateurs who use 75 ohm transmission line for this reason. If you're going to run an antenna tuner anyway, and if you're going to build your own antennas anyway, then it's not a bad way to get a bit more bang for the buck.
$endgroup$
– TimWescott
7 hours ago
$begingroup$
@TimWescott specifically, this: qsl.net/g4hbt/dipole.htm antenna specifies a 75 ohm line. I finally understand why.
$endgroup$
– hjf
7 hours ago
$begingroup$
@TimWescott specifically, this: qsl.net/g4hbt/dipole.htm antenna specifies a 75 ohm line. I finally understand why.
$endgroup$
– hjf
7 hours ago
$begingroup$
It was 75 ohms for RF signals before cable TV was a "thing". I've always figured it was the cable manufacturers, so they could force you to buy two spools of cable instead of just one. And the connector manufacturers, so they could sell you two different sizes of connectors.
$endgroup$
– Hot Licks
6 hours ago
$begingroup$
It was 75 ohms for RF signals before cable TV was a "thing". I've always figured it was the cable manufacturers, so they could force you to buy two spools of cable instead of just one. And the connector manufacturers, so they could sell you two different sizes of connectors.
$endgroup$
– Hot Licks
6 hours ago
add a comment |
2 Answers
2
active
oldest
votes
$begingroup$
How is transmission line impedance selected? explains why transmission line impedance matters.
The CATV industry deals with low-level signals, so it cares ONLY about loss and not at all about power-handling. That's why they chose 75Ω transmission lines.
answered 7 hours ago
Dave Tweed♦Dave Tweed
123k9152265
$endgroup$
$begingroup$
Awesome! I didn't know that thing about power, and now I also understand why NOAA reception turnstile antennas specify 75 ohms too!
$endgroup$
– hjf
7 hours ago
add a comment |
$begingroup$
catv was created when copper prices started a runout then the standard of 75h was to adapting wire lenth estimation and the influence of cheaper copper regarding its thermal and resistance drift in outdoors conditions to sun heat and cold. it coulld have been 100 or 50 but it's not...
answered 51 mins ago
banterbanter
1
New contributor
banter is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
$endgroup$
add a comment |
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2 Answers
2
active
oldest
votes
2 Answers
2
active
oldest
votes
active
oldest
votes
active
oldest
votes
$begingroup$
How is transmission line impedance selected? explains why transmission line impedance matters.
The CATV industry deals with low-level signals, so it cares ONLY about loss and not at all about power-handling. That's why they chose 75Ω transmission lines.
answered 7 hours ago
Dave Tweed♦Dave Tweed
123k9152265
$endgroup$
$begingroup$
Awesome! I didn't know that thing about power, and now I also understand why NOAA reception turnstile antennas specify 75 ohms too!
$endgroup$
– hjf
7 hours ago
add a comment |
$begingroup$
How is transmission line impedance selected? explains why transmission line impedance matters.
The CATV industry deals with low-level signals, so it cares ONLY about loss and not at all about power-handling. That's why they chose 75Ω transmission lines.
answered 7 hours ago
Dave Tweed♦Dave Tweed
123k9152265
$endgroup$
$begingroup$
Awesome! I didn't know that thing about power, and now I also understand why NOAA reception turnstile antennas specify 75 ohms too!
$endgroup$
– hjf
7 hours ago
add a comment |
$begingroup$
How is transmission line impedance selected? explains why transmission line impedance matters.
The CATV industry deals with low-level signals, so it cares ONLY about loss and not at all about power-handling. That's why they chose 75Ω transmission lines.
answered 7 hours ago
Dave Tweed♦Dave Tweed
123k9152265
$endgroup$
How is transmission line impedance selected? explains why transmission line impedance matters.
The CATV industry deals with low-level signals, so it cares ONLY about loss and not at all about power-handling. That's why they chose 75Ω transmission lines.
answered 7 hours ago
Dave Tweed♦Dave Tweed
123k9152265
answered 7 hours ago
Dave Tweed♦Dave Tweed
123k9152265
answered 7 hours ago
Dave Tweed♦Dave Tweed
123k9152265
answered 7 hours ago
Dave Tweed♦Dave Tweed
123k9152265
123k9152265
$begingroup$
Awesome! I didn't know that thing about power, and now I also understand why NOAA reception turnstile antennas specify 75 ohms too!
$endgroup$
– hjf
7 hours ago
add a comment |
$begingroup$
Awesome! I didn't know that thing about power, and now I also understand why NOAA reception turnstile antennas specify 75 ohms too!
$endgroup$
– hjf
7 hours ago
$begingroup$
Awesome! I didn't know that thing about power, and now I also understand why NOAA reception turnstile antennas specify 75 ohms too!
$endgroup$
– hjf
7 hours ago
$begingroup$
Awesome! I didn't know that thing about power, and now I also understand why NOAA reception turnstile antennas specify 75 ohms too!
$endgroup$
– hjf
7 hours ago
add a comment |
$begingroup$
catv was created when copper prices started a runout then the standard of 75h was to adapting wire lenth estimation and the influence of cheaper copper regarding its thermal and resistance drift in outdoors conditions to sun heat and cold. it coulld have been 100 or 50 but it's not...
answered 51 mins ago
banterbanter
1
New contributor
banter is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
$endgroup$
add a comment |
$begingroup$
catv was created when copper prices started a runout then the standard of 75h was to adapting wire lenth estimation and the influence of cheaper copper regarding its thermal and resistance drift in outdoors conditions to sun heat and cold. it coulld have been 100 or 50 but it's not...
answered 51 mins ago
banterbanter
1
New contributor
banter is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
$endgroup$
add a comment |
$begingroup$
catv was created when copper prices started a runout then the standard of 75h was to adapting wire lenth estimation and the influence of cheaper copper regarding its thermal and resistance drift in outdoors conditions to sun heat and cold. it coulld have been 100 or 50 but it's not...
answered 51 mins ago
banterbanter
1
New contributor
banter is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
$endgroup$
catv was created when copper prices started a runout then the standard of 75h was to adapting wire lenth estimation and the influence of cheaper copper regarding its thermal and resistance drift in outdoors conditions to sun heat and cold. it coulld have been 100 or 50 but it's not...
answered 51 mins ago
banterbanter
1
New contributor
banter is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
answered 51 mins ago
banterbanter
1
New contributor
banter is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
answered 51 mins ago
banterbanter
1
answered 51 mins ago
banterbanter
1
1
New contributor
banter is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
New contributor
banter is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
banter is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
add a comment |
add a comment |
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$begingroup$
Some insight is in Andy's answer:electronics.stackexchange.com/questions/350451/…
$endgroup$
– glen_geek
7 hours ago
1
$begingroup$
I'm not sure if I should say "a substantial minority" or "enough so that it's known" -- but there are radio amateurs who use 75 ohm transmission line for this reason. If you're going to run an antenna tuner anyway, and if you're going to build your own antennas anyway, then it's not a bad way to get a bit more bang for the buck.
$endgroup$
– TimWescott
7 hours ago
$begingroup$
@TimWescott specifically, this: qsl.net/g4hbt/dipole.htm antenna specifies a 75 ohm line. I finally understand why.
$endgroup$
– hjf
7 hours ago
$begingroup$
It was 75 ohms for RF signals before cable TV was a "thing". I've always figured it was the cable manufacturers, so they could force you to buy two spools of cable instead of just one. And the connector manufacturers, so they could sell you two different sizes of connectors.
$endgroup$
– Hot Licks
6 hours ago