>2 wrote:
>>
>>
>>>2 wrote:
>>>>An IR thermometer, a manometer, and some horse sense are more
>>>>trustworthy than computer modeling -- i. e., if the thermometer says
>>>>it's too damn hot, and the computer app says it's not, it is.
>>>>
>>>
>>>They used to say that about antennas too, until MININEC and NEC became
>>>available free to anyone who wants them. Certainly there are big
>>>pitfalls in computer modeling, but antenna modeling has also shown that
>>>"horse sense" isn't always reliable either. In the end, you need both,
>>>in order to check each against the other.
>>
>>So if horse sense yagi-uda design -- i.e., tuning for max fwd gain on an
>>antenna test range - with element length/spacing experimentation produces
>>more gain than the computer modeling antenna, one should assume that the
>>fault is with the test range ?
>
>In all areas of engineering, professionals routinely do both modeling
>and measurement, and use each to check the other.
>
>Setting up modeling "versus" measurement, and turning it into an
>argument, is strictly an amateur thing. It's time we grew out of it.
>
When a omputer modeling program produces better results on the antenna
test range, there is no argument. When it does not, it becomes a
laughing stock.
>>>
>>>
>>>Exactly the same would apply to thermal/flow modeling if we had the
>>>tools to try it.
>>>
>>>
>>>Unfortunately IR thermometers are notoriously UNtrustworthy, unless they
>>>are calibrated for emissivity and - for this application - also have a
>>>very small spot measurement size.
>>>
>>The better ones have a light-beam guide spot.
>>
>The guide spot is a laser beam. The *sensing* spot can be an inch
>across, or larger.
The guide spot assures alignment.
>
>
>[...]
> >Black shoe polish is not costly.
>[...]
>>Drill a hole, make the measurement, and tape the hole with aluminum tape.
>
>I'd rather find better ways...
>
Some build amplifiers to look good. I build amplifiers primarily to
deliver the goods.
- R. L. Measures, a.k.a. Rich..., 805.386.3734,AG6K,
www.vcnet.com/measures.
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