[Heathkit] Fwd: My Earlier Post

[Doug Renwick]

What the hell is wrong with Don?  Normal folks do not behave this way.

Doug

I'll run the race and I will never be the same again. 

>-----Original Message-----
>
>OK, I wasn't going to say anything but since others are talking about
>it, I'd like the chance to set the record straight - I am the engineer
>in question and I certainly didn't try or mean to chastise Don and
>have apologized to him. I tried to make a joke about being a
>"professional engineer" because he made a joke about probably being
>wrong because "we're all amateurs".
>
>I sent what was intended and what I thought was a helpful,
>light-hearted private message trying to explain cable capacitance
>which his mail indicated he was confused about. But sometimes things
>just don't come across as intended.
>No good deed goes unpunished as they say.
>End of topic I hope.
>73 to everyone,
>Nick K4NYW
>
>======= What I sent Don ========
>Hi Don  --
>Well, I'm a radio amateur but a professional electronics engineer -
>the capacitance of cable is indeed from conductor to conductor (center
>to shield on co-ax) so it is definitely a shunt on the signal, not a
>series capacitance. Just think about how a capacitor is made - a
>sandwich of a conductor, a dielectric insulator, and another conductor
>- make the area of the sandwich bigger and the capacitance goes up,
>make the dielectric thicker and the capacitance goes down. Co-ax is
>just a funny shaped sandwich.
>
>For the purposes of this discussion I'm assuming a short piece of
>co-ax compared to a wavelength. because cable acts like a transmission
>line as it gets longer and that's a whole 'nother kettle of fish. The
>transmission line can be viewed as a endless array of series inductors
>and parallel capacitors (and the L/C ratio determines the
>characteristic impedance Z=sqrt(L/C))
>
>--L---L---L---L---L---L---L---L---L---L.......
>   |    |    |    |    |    |    |    |    |  ......
>   C  C   C  C  C  C   C   C   C
>   |    |    |    |    |    |    |    |    |  ......
>------------------------------------------------.......
>
>cheers,
>Nick K4NYW
>====== What Don posted ========
>>My apologies to the group for trying to be helpful earlier.  I was
>>sufficiently chastised off list, by a "professional engineer".  I'll just
>>stick to helping with parts, etc when I can and re-enter my cave.
>>73,
>>Don, WB5HAK
>====== My reply to that ===========
>Oh come on, Don. You ended your mail with "but we're all amateurs" so I was
>just trying to make a joke. I do apologize for offending you. That
certainly
>was not my intention and was just trying to help you better understand a
>complex subject.
>
>Please accept my sincere apologies from a fellow who cheerfully
acknowledges
>he is downright ignorant about many many things.
>73
>Nick K4NYW
>==================================