On Apr 12, 10:34�am, wrote:
On 12 Apr 2007 11:24:43 -0700, "AF6AY" wrote:
On Apr 11, 3:33?pm, wrote:
On 11 Apr 2007 16:20:45 -0700, "AF6AY" wrote:
From: Dave Heil on Wed, 11 Apr 2007 03:27:14 GMT
AF6AY wrote:
From: on 10 Apr 2007 03:56:54 -0700
On Apr 9, 1:05 pm, Dave Heil wrote:
wrote:
On Apr 9, 2:05 am, Dave Heil wrote:
wrote:
On Apr 7, 5:31 pm, wrote:
On Apr 3, 1:34?pm, "AF6AY" wrote:
On Mar 29, 6:24?pm, Dave Heil wrote a typical


Hey, no sweat, Mark. *I didn't decide until February 17, 2007, seeing
a very local test session available on February 25; I was busy with
other things on Friday the 23rd. *For me it was just "cram time"
just like college days or the impossible-to-do-in-assigned-time-
frame work assignments...download the QPs fromwww.ncvec.org,
do a bunch of on-line practice tests (all of passing grades).

tell me *what could you use the vecctor stuf witht he imagainary
number on in Ham radio I learned some that cstuff in college NEVER
found a use for it at all

The Real + jImaginary numbers are excellent for handling
Impedance and Admittance when there is a requirement in
equating the Imaginary part (Reactance or Susceptance)
to zero as in antenna matching over a narrow frequency
range. It is also excellent for Impedance/Admittance
matching in interstage tuned circuits (both receivers and
transmitters).

The "vector stuff" lets one quickly visualize, for example,
the frequency characteristics of any antenna on a Smith
Chart. A Z or Y Bridge or "Noise Bridge" (low-cost version
of the more classic bridges) tells one the Resistance or
Conductance and the Reactance or Susceptance of an
antenna or the input to either a transmitter stage or the
input to a receiver. Usually a Noise Bridge yields Y and
the value of the resistive component (G) and the
Susceptive componet (B); that is the equivalent of a
paralleled resistance and capacitance/inductance at one
frequency. Knowing complex number handling allows
easy conversion to Z (the series impedance form) and
the equivalent value of R (resistance) and X (reactance).

In one case a few decades ago, I was able to "rotate" the
characteristics of 8 different SAW filters around a Smith
Chart to equal a near-all-resistive correct value with the
capacitive part cancelled to near-zero for best power
transfer into the SAW filter...using the determined length
of small coaxial cable. Saved a lot of space as opposed
to an elaborate matching network.

(indeed might make passing the exam easier if I had never seen it
before studing it for an ham exam)

Well, yes, but you (and I and everyone else) cannot know
future requirements, can we? :-) Handling complex
quantities is very basic and can come in very handy.

The usual ham who doesn't build or bother to check antennas
more than "open" or "closed' connections won't bother with
it, An antenna tuner, manual or automatic, can do all that
stuff of matching. But, is it better to remain ignorant of
certain operating characteristics of one's station or try to
know it in more specific detail? :-)

73, Len AF6AY