[LAU] hardware - Intel CPUs

[Simon Wise]

On 17/04/14 12:11, Gene Heskett wrote:
> On Wednesday 16 April 2014 21:57:21 Simon Wise did opine:
>
>> On 16/04/14 23:20, Gene Heskett wrote:
>>> On Wednesday 16 April 2014 09:09:06 Simon Wise did opine:
>>>> I was shown a rather nice artwork that used high resolution radar
>>>> (resolutions around 1 centimetre I think) to get positions (it was
>>>> made in a university robotics department that had such things!). The
>>>> way those work is very interesting ... the frequencies are way to
>>>> high to digitise, so the electronics has to be all analogue ... the
>>>> 'circuitry' is basically plumbing ... gold lined tubes and chambers
>>>> using resonances and such to measure delays and phase differences.
>>>> At those frequencies the speed of light becomes a dominant
>>>> consideration.
>>>
>>> We have a gismo thats basically much simpler than all that plumbing,
>>> to use when checking a cable for damage, called a Time Domain
>>> Reflectometer.  The pro versions using a tunnel diode switch as a
>>> pulse generator, can tell you theres a bullethole in the line 883.6'
>>> out from where you are hooked up. I've made homemade versions using a
>>> pulse generator and a fast oscilloscope to measure the echo delay,
>>> punched some buttons on a good calculator and then told the tower
>>> crew where to open it up and replace a burned up connector bullet
>>> and/or the teflon disk holding it centered in the line. It got the
>>> job done so I figured it was good enough for the girls I go with. :)
>>
>> not at all convinced that a fast oscilloscope, a good calculator and the
>> wet-ware connecting them are simpler than a bit of machined metal with
>> gold plating, but certainly re-using existing gadgets beats making new
>> ones.
>>
> Either method requires that the operator have intimate knowledge of the
> characteristics of the transmission line being measured.  That is
> considerably more important then the cost of the tool, particularly when
> the results are adequate for the job at hand.

indeed, it is often so


Simon