Reply by Clifford Heath●October 11, 20212021-10-11
On 11/10/21 4:35 am, Jeroen Belleman wrote:
> On 2021-10-10 17:58, jlarkin@highlandsniptechnology.com wrote:
>> On Sun, 10 Oct 2021 02:20:32 -0500, John S <Sophi.2@invalid.org>
>> wrote:
>>
>>> On 10/8/2021 8:48 PM, jlarkin@highlandsniptechnology.com wrote:
>>>> On Fri, 08 Oct 2021 22:10:47 +0200, Jeroen Belleman
>>>> <jeroen@nospam.please> wrote:
>>>>
>>>>> On 2021-10-08 21:07, John Larkin wrote:
>>>>>> On Fri, 8 Oct 2021 12:02:25 -0500, amdx <amdx@knology.net> wrote:
>>>>>>
>>>>>>> On 10/8/2021 11:18 AM, jlarkin@highlandsniptechnology.com wrote:
>>>>>>>> On Fri, 8 Oct 2021 10:05:15 -0500, amdx <amdx@knology.net> wrote:
>>>>>>>>
>>>>>>>>> Here's a AT&T Labs archive video, showing an interesting
>>>>>>>>> machine used to
>>>>>>>>> demonstrate wave behavior.
>>>>>>>>>
>>>>>>>>> Shows� open and shorted end, mismatched termination, matching
>>>>>>>>> line,
>>>>>>>>> wideband matching line etc.
>>>>>>>>>
>>>>>>>>> ���� Very cool.
>>>>>>>>>
>>>>>>>>>> https://www.youtube.com/watch?v=DovunOxlY1k&t=297s
>>>>>>>>> ������������������������������� Mikek
>>>>>>>> Hilariously wrong.
>>>>>>>>
>>>>>>> ��� Hi John, if you are smart enough to call an AT&T Labs video,
>>>>>>> "Hilariously wrong"
>>>>>>> It seems like you could convey the information about where they
>>>>>>> are wrong.
>>>>>>> I doubt everything said in the video is wrong.
>>>>>>> ������������������������������� Mikek
>>>>>>
>>>>>> An open transmission line does not invert the reflection. That's as
>>>>>> far as I watched it, so other stuff may be funny too.
>>>>>>
>>>>>
>>>>> He's talking of current, not voltage. He says so a few times.
>>>>>
>>>>> Jeroen Belleman
>>>>
>>>> Ok, let's change hilariously wrong to hilariously weird.
>>>>
>>>
>>> What's weird about it? You don't understand it?
>>
>> I test transmission lines with oscilloscopes, not ammeters.
>
> I've been having thoughts about inserting a directional
> coupler between the pulse generator and the scope, so that
> it will show /only/ the reflection, not its superposition with
> the incident signal. I think I can make a coupler with the
> necessary bandwidth, a few tens of kHz up to 10 GHz or so.
Reply by Jeroen Belleman●October 11, 20212021-10-11
On 2021-10-10 22:00, jlarkin@highlandsniptechnology.com wrote:
> On Sun, 10 Oct 2021 19:35:03 +0200, Jeroen Belleman
> <jeroen@nospam.please> wrote:
>
>> On 2021-10-10 17:58, jlarkin@highlandsniptechnology.com wrote:
>>> On Sun, 10 Oct 2021 02:20:32 -0500, John S <Sophi.2@invalid.org>
>>> wrote:
>>>
>>>> On 10/8/2021 8:48 PM, jlarkin@highlandsniptechnology.com wrote:
>>>>> On Fri, 08 Oct 2021 22:10:47 +0200, Jeroen Belleman
>>>>> <jeroen@nospam.please> wrote:
>>>>>
>>>>>> On 2021-10-08 21:07, John Larkin wrote:
>>>>>>> On Fri, 8 Oct 2021 12:02:25 -0500, amdx <amdx@knology.net> wrote:
>>>>>>>
>>>>>>>> On 10/8/2021 11:18 AM, jlarkin@highlandsniptechnology.com wrote:
>>>>>>>>> On Fri, 8 Oct 2021 10:05:15 -0500, amdx <amdx@knology.net> wrote:
>>>>>>>>>
>>>>>>>>>> Here's a AT&T Labs archive video, showing an interesting machine used to
>>>>>>>>>> demonstrate wave behavior.
>>>>>>>>>>
>>>>>>>>>> Shows open and shorted end, mismatched termination, matching line,
>>>>>>>>>> wideband matching line etc.
>>>>>>>>>>
>>>>>>>>>> Very cool.
>>>>>>>>>>
>>>>>>>>>>> https://www.youtube.com/watch?v=DovunOxlY1k&t=297s
>>>>>>>>>> Mikek
>>>>>>>>> Hilariously wrong.
>>>>>>>>>
>>>>>>>> Hi John, if you are smart enough to call an AT&T Labs video, "Hilariously wrong"
>>>>>>>> It seems like you could convey the information about where they are wrong.
>>>>>>>> I doubt everything said in the video is wrong.
>>>>>>>> Mikek
>>>>>>>
>>>>>>> An open transmission line does not invert the reflection. That's as
>>>>>>> far as I watched it, so other stuff may be funny too.
>>>>>>>
>>>>>>
>>>>>> He's talking of current, not voltage. He says so a few times.
>>>>>>
>>>>>> Jeroen Belleman
>>>>>
>>>>> Ok, let's change hilariously wrong to hilariously weird.
>>>>>
>>>>
>>>> What's weird about it? You don't understand it?
>>>
>>> I test transmission lines with oscilloscopes, not ammeters.
>>
>> I've been having thoughts about inserting a directional
>> coupler between the pulse generator and the scope, so that
>> it will show /only/ the reflection, not its superposition with
>> the incident signal. I think I can make a coupler with the
>> necessary bandwidth, a few tens of kHz up to 10 GHz or so.
>>
>> Would it be worth the trouble?
>>
>> Jeroen Belleman
>
> Couldn't you capture the pulse into a 50 ohm load, and then into your
> DUT, and subtract?
>
>
>
I suppose so. After all, that's sort-of what a directional coupler does.
I'll give it a shot when I get to the lab tomorrow. (I've been slowing
down lately. My retirement is not far off.)
Jeroen Belleman
Reply by John S●October 10, 20212021-10-10
On 10/10/2021 10:58 AM, jlarkin@highlandsniptechnology.com wrote:
> On Sun, 10 Oct 2021 02:20:32 -0500, John S <Sophi.2@invalid.org>
> wrote:
>
>> On 10/8/2021 8:48 PM, jlarkin@highlandsniptechnology.com wrote:
>>> On Fri, 08 Oct 2021 22:10:47 +0200, Jeroen Belleman
>>> <jeroen@nospam.please> wrote:
>>>
>>>> On 2021-10-08 21:07, John Larkin wrote:
>>>>> On Fri, 8 Oct 2021 12:02:25 -0500, amdx <amdx@knology.net> wrote:
>>>>>
>>>>>> On 10/8/2021 11:18 AM, jlarkin@highlandsniptechnology.com wrote:
>>>>>>> On Fri, 8 Oct 2021 10:05:15 -0500, amdx <amdx@knology.net> wrote:
>>>>>>>
>>>>>>>> Here's a AT&T Labs archive video, showing an interesting machine used to
>>>>>>>> demonstrate wave behavior.
>>>>>>>>
>>>>>>>> Shows open and shorted end, mismatched termination, matching line,
>>>>>>>> wideband matching line etc.
>>>>>>>>
>>>>>>>> Very cool.
>>>>>>>>
>>>>>>>>> https://www.youtube.com/watch?v=DovunOxlY1k&t=297s
>>>>>>>> Mikek
>>>>>>> Hilariously wrong.
>>>>>>>
>>>>>> Hi John, if you are smart enough to call an AT&T Labs video, "Hilariously wrong"
>>>>>> It seems like you could convey the information about where they are wrong.
>>>>>> I doubt everything said in the video is wrong.
>>>>>> Mikek
>>>>>
>>>>> An open transmission line does not invert the reflection. That's as
>>>>> far as I watched it, so other stuff may be funny too.
>>>>>
>>>>
>>>> He's talking of current, not voltage. He says so a few times.
>>>>
>>>> Jeroen Belleman
>>>
>>> Ok, let's change hilariously wrong to hilariously weird.
>>>
>>
>> What's weird about it? You don't understand it?
>
> I test transmission lines with oscilloscopes, not ammeters.
>
That's weird.
Reply by boB●October 10, 20212021-10-10
On Sun, 10 Oct 2021 02:22:42 -0500, John S <Sophi.2@invalid.org>
wrote:
>On 10/8/2021 10:05 AM, amdx wrote:
>> Here's a AT&T Labs archive video, showing an interesting machine used to
>> demonstrate wave behavior.
>>
>> Shows� open and shorted end, mismatched termination, matching line,
>> wideband matching line etc.
>>
>> �Very cool.
>>
>>> https://www.youtube.com/watch?v=DovunOxlY1k&t=297s
>>
>> ��������������������������� Mikek
>
>
>Great video, Mikek. Thanks for the link.
On Sat, 9 Oct 2021 21:53:34 -0700 (PDT), Rick C
<gnuarm.deletethisbit@gmail.com> wrote:
>On Saturday, October 9, 2021 at 2:49:01 PM UTC-4, jla...@highlandsniptechnology.com wrote:
>> On Fri, 8 Oct 2021 21:15:00 +0100, "Kevin Aylward"
>> <kevinRemoveandReplaceATkevinaylward.co.uk> wrote:
>>
>> >wrote in message news:spr0mg1lu7qpq13as...@4ax.com...
>> >
>> >On Fri, 8 Oct 2021 10:05:15 -0500, amdx <am...@knology.net> wrote:
>> >
>> >>>Here's a AT&T Labs archive video, showing an interesting machine used to
>> >>>demonstrate wave behavior.
>> >>
>> >>>Shows open and shorted end, mismatched termination, matching line,
>> >>>wideband matching line etc.
>> >>
>> >> >Very cool.
>> >>
>> >>>> https://www.youtube.com/watch?v=DovunOxlY1k&t=297s
>> >>
>> >> Mikek
>> >
>> >>Hilariously wrong.
>> >
>> >
>> >I agree he got it backwards with regard to the electrical line, he got the
>> >analogy wrong...however...it was still a nice video....
>> >
>> >
I would believe a Bell Labs video over most anybody on this newsgroup
Might be a difference of presentation that isn't clear to some
>> >
>> >-- Kevin Aylward
>> >
>> >http://www.anasoft.co.uk/ SuperSpice
>> >http://www.kevinaylward.co.uk/ee/index.html
>> He's right if the txline graph is current. Maybe the Bell system did
>> all their telecom measurements in amps?
>
>If you actually pay attention to what he says, he states that he is talking about current.
>
>https://youtu.be/DovunOxlY1k?t=330
>
>You just have to pay attention in class.
Bell Labs was good at all kinds of units of measurement.
The Bel was useful too.
In Munich at the museum of science, I saw George Ohm's original Fluke
meter !
boB
Reply by Jeroen Belleman●October 10, 20212021-10-10
On 2021-10-10 17:58, jlarkin@highlandsniptechnology.com wrote:
> On Sun, 10 Oct 2021 02:20:32 -0500, John S <Sophi.2@invalid.org>
> wrote:
>
>> On 10/8/2021 8:48 PM, jlarkin@highlandsniptechnology.com wrote:
>>> On Fri, 08 Oct 2021 22:10:47 +0200, Jeroen Belleman
>>> <jeroen@nospam.please> wrote:
>>>
>>>> On 2021-10-08 21:07, John Larkin wrote:
>>>>> On Fri, 8 Oct 2021 12:02:25 -0500, amdx <amdx@knology.net> wrote:
>>>>>
>>>>>> On 10/8/2021 11:18 AM, jlarkin@highlandsniptechnology.com wrote:
>>>>>>> On Fri, 8 Oct 2021 10:05:15 -0500, amdx <amdx@knology.net> wrote:
>>>>>>>
>>>>>>>> Here's a AT&T Labs archive video, showing an interesting machine used to
>>>>>>>> demonstrate wave behavior.
>>>>>>>>
>>>>>>>> Shows open and shorted end, mismatched termination, matching line,
>>>>>>>> wideband matching line etc.
>>>>>>>>
>>>>>>>> Very cool.
>>>>>>>>
>>>>>>>>> https://www.youtube.com/watch?v=DovunOxlY1k&t=297s
>>>>>>>> Mikek
>>>>>>> Hilariously wrong.
>>>>>>>
>>>>>> Hi John, if you are smart enough to call an AT&T Labs video, "Hilariously wrong"
>>>>>> It seems like you could convey the information about where they are wrong.
>>>>>> I doubt everything said in the video is wrong.
>>>>>> Mikek
>>>>>
>>>>> An open transmission line does not invert the reflection. That's as
>>>>> far as I watched it, so other stuff may be funny too.
>>>>>
>>>>
>>>> He's talking of current, not voltage. He says so a few times.
>>>>
>>>> Jeroen Belleman
>>>
>>> Ok, let's change hilariously wrong to hilariously weird.
>>>
>>
>> What's weird about it? You don't understand it?
>
> I test transmission lines with oscilloscopes, not ammeters.
I've been having thoughts about inserting a directional
coupler between the pulse generator and the scope, so that
it will show /only/ the reflection, not its superposition with
the incident signal. I think I can make a coupler with the
necessary bandwidth, a few tens of kHz up to 10 GHz or so.
Would it be worth the trouble?
Jeroen Belleman
Reply by ●October 10, 20212021-10-10
On Sun, 10 Oct 2021 02:20:32 -0500, John S <Sophi.2@invalid.org>
wrote:
>On 10/8/2021 8:48 PM, jlarkin@highlandsniptechnology.com wrote:
>> On Fri, 08 Oct 2021 22:10:47 +0200, Jeroen Belleman
>> <jeroen@nospam.please> wrote:
>>
>>> On 2021-10-08 21:07, John Larkin wrote:
>>>> On Fri, 8 Oct 2021 12:02:25 -0500, amdx <amdx@knology.net> wrote:
>>>>
>>>>> On 10/8/2021 11:18 AM, jlarkin@highlandsniptechnology.com wrote:
>>>>>> On Fri, 8 Oct 2021 10:05:15 -0500, amdx <amdx@knology.net> wrote:
>>>>>>
>>>>>>> Here's a AT&T Labs archive video, showing an interesting machine used to
>>>>>>> demonstrate wave behavior.
>>>>>>>
>>>>>>> Shows open and shorted end, mismatched termination, matching line,
>>>>>>> wideband matching line etc.
>>>>>>>
>>>>>>> Very cool.
>>>>>>>
>>>>>>>> https://www.youtube.com/watch?v=DovunOxlY1k&t=297s
>>>>>>> Mikek
>>>>>> Hilariously wrong.
>>>>>>
>>>>> Hi John, if you are smart enough to call an AT&T Labs video, "Hilariously wrong"
>>>>> It seems like you could convey the information about where they are wrong.
>>>>> I doubt everything said in the video is wrong.
>>>>> Mikek
>>>>
>>>> An open transmission line does not invert the reflection. That's as
>>>> far as I watched it, so other stuff may be funny too.
>>>>
>>>
>>> He's talking of current, not voltage. He says so a few times.
>>>
>>> Jeroen Belleman
>>
>> Ok, let's change hilariously wrong to hilariously weird.
>>
>
>What's weird about it? You don't understand it?
I test transmission lines with oscilloscopes, not ammeters.
--
Father Brown's figure remained quite dark and still;
but in that instant he had lost his head. His head was
always most valuable when he had lost it.
Reply by John S●October 10, 20212021-10-10
On 10/8/2021 10:05 AM, amdx wrote:
> Here's a AT&T Labs archive video, showing an interesting machine used to
> demonstrate wave behavior.
>
> Shows open and shorted end, mismatched termination, matching line,
> wideband matching line etc.
>
> Very cool.
>
>> https://www.youtube.com/watch?v=DovunOxlY1k&t=297s
>
> Mikek
Great video, Mikek. Thanks for the link.
Reply by John S●October 10, 20212021-10-10
On 10/8/2021 8:48 PM, jlarkin@highlandsniptechnology.com wrote:
> On Fri, 08 Oct 2021 22:10:47 +0200, Jeroen Belleman
> <jeroen@nospam.please> wrote:
>
>> On 2021-10-08 21:07, John Larkin wrote:
>>> On Fri, 8 Oct 2021 12:02:25 -0500, amdx <amdx@knology.net> wrote:
>>>
>>>> On 10/8/2021 11:18 AM, jlarkin@highlandsniptechnology.com wrote:
>>>>> On Fri, 8 Oct 2021 10:05:15 -0500, amdx <amdx@knology.net> wrote:
>>>>>
>>>>>> Here's a AT&T Labs archive video, showing an interesting machine used to
>>>>>> demonstrate wave behavior.
>>>>>>
>>>>>> Shows open and shorted end, mismatched termination, matching line,
>>>>>> wideband matching line etc.
>>>>>>
>>>>>> Very cool.
>>>>>>
>>>>>>> https://www.youtube.com/watch?v=DovunOxlY1k&t=297s
>>>>>> Mikek
>>>>> Hilariously wrong.
>>>>>
>>>> Hi John, if you are smart enough to call an AT&T Labs video, "Hilariously wrong"
>>>> It seems like you could convey the information about where they are wrong.
>>>> I doubt everything said in the video is wrong.
>>>> Mikek
>>>
>>> An open transmission line does not invert the reflection. That's as
>>> far as I watched it, so other stuff may be funny too.
>>>
>>
>> He's talking of current, not voltage. He says so a few times.
>>
>> Jeroen Belleman
>
> Ok, let's change hilariously wrong to hilariously weird.
>
What's weird about it? You don't understand it?
Reply by John S●October 10, 20212021-10-10
On 10/8/2021 7:38 PM, amdx wrote:
> On 10/8/2021 3:10 PM, Jeroen Belleman wrote:
>> On 2021-10-08 21:07, John Larkin wrote:
>>> On Fri, 8 Oct 2021 12:02:25 -0500, amdx <amdx@knology.net> wrote:
>>>
>>>> On 10/8/2021 11:18 AM, jlarkin@highlandsniptechnology.com wrote:
>>>>> On Fri, 8 Oct 2021 10:05:15 -0500, amdx <amdx@knology.net> wrote:
>>>>>
>>>>>> Here's a AT&T Labs archive video, showing an interesting machine
>>>>>> used to
>>>>>> demonstrate wave behavior.
>>>>>>
>>>>>> Shows� open and shorted end, mismatched termination, matching line,
>>>>>> wideband matching line etc.
>>>>>>
>>>>>> �� Very cool.
>>>>>>
>>>>>>> https://www.youtube.com/watch?v=DovunOxlY1k&t=297s
>>>>>> ����������������������������� Mikek
>>>>> Hilariously wrong.
>>>>>
>>>> � Hi John, if you are smart enough to call an AT&T Labs video,
>>>> "Hilariously wrong"
>>>> It seems like you could convey the information about where they are
>>>> wrong.
>>>> I doubt everything said in the video is wrong.
>>>> ����������������������������� Mikek
>>>
>>> An open transmission line does not invert the reflection. That's as
>>> far as I watched it, so other stuff may be funny too.
>>>
>>
>> He's talking of current, not voltage. He says so a few times.
>>
>> Jeroen Belleman
>
> �So, it looks like John watched part of the video, saw one point that
> he got wrong,
>
> then he goes on the label the whole video, "Hilariously wrong".
>
> � John, do you care to watch it and pick anything else apart.
>
> Or could you say, "I got it wrong, the demo device is pretty neat, and
> the video was
>
> well planned before filming was started"?
>
> ������������������������������������������ Mikek
Also, he mentioned inversion near the beginning when he was drawing and
explaning the operation of the line. It was clear to me and appeared
correct.
Perhaps John can give us a time in the video to examine?