"art" wrote in message
ups.com...
On 8 Apr, 17:52, "Jimmie D" wrote:
"art" wrote in message

oups.com...





On 6 Apr, 08:48, (Richard Harrison) wrote:
Art wrote:

"Frankly a lot of people on this net need to get up to speed with
respect to radiation such as tipped antennas ---."

Yesterday`s response seems to have been gobbled in cyber space.

Not all my reference books are over 50 years old. One of my best was
published in 2003 although its principal author was born in 1910. He
is
J.D. Kraus, but he had numerous and likely younger collaborators, 6 of
whom are listed as co-authors. The title: "Antennas For All
Applications. 3rd edition".

On page 297 is found an item which illustrates what happens when you
tip
an antenna. It is titled: "Antenna Rotation Experiments":
"Consider the radio circuit shown in Fig. 8-74a in which one antenna
is
circularly polarized (a turnstile?) and the other is linearly
polarized.
If one of the antennas is rotated about its axis a frequency f (r/s),
the received signal is shifted to F + or - f, where F is the
transmitter
frequency."

Fig. 8-74 notes:
"Antenna rotation produces amplitude modulation."

Of course it does. When the linear antenna is aligned parallel to one
axis of the CP antenna, the signal is maximum. When the linear antenna
is most misaligned with either axis of the CP antenna, signal is a
minimum. The example demonstrates why polarization alignment, not
tipping or tilt, is usually important.

Best regards, Richard Harrison, KB5WZI

Richard, I couldn't find my Kraus book so I will have to let your
comment go.
I did look in the Jasik book on parasitic elements.
It said"A parrasitic element properly tuned will operate in phase-and-
field relationships
approximating those computed.In multi element arrays, independent
control and phase and amplitude is required and parasitics should be
avoided. However, they may be employed in antennas
designed primarily for power gain" To me this describes a yagi with
parasitic elements designed for power gain regardless of the mix of
polarisation. The Gauss system which does not use parasitics and
therefore pursues the independent control AND PHASE AND AMPLITUDE.
A yagi in a 90 degree multiple of earth does operate in a field
relationship because of its multi phase radiation where as the
gaussion tilts to remove unwanted phase and keeps only the required
phase. This is extremely important in cell transmittions since
channels are only of use when the polarisation is correct and any area
that does not comprise of the correct polarisation results in a
dropped call.
In my last post I mentioned the slope between scanning lines on a T.V.
as a reference line for true polarity. Any comment with respect to the
veracity of that statement since I see a direct corrorally between
that and radiation tilt angles?
Best regards
Art

Perhaps you should actually make an effort to explain why you see the
relationships you see. I can think of no reason why anyone should be
expected to go into great detail to explain your fallacies while you use
almost no effort to explain why you think you are right.

Jimmie- Hide quoted text -

- Show quoted text -

Jimmie
As I said earlier the crt picture was in a Terman book. The picture
showed a series of scan lines across the screen at a slight angle.
Drawn at right angles to the sloping lines was a square i.e. bisected
by the scan line. It was stated that the square represented aperture.
Thus both the scan line and the aperture was tilted away from 90
degrees to the earth.
As I said earlier for purity of polarization a vertical dipole would
have to be tilted approx 3 degrees. All this is a repeat of my last
post which I consider an effort to rebutt what you call a "fallacy".
I see similarities with what I stated earlier with respect to
antennas. I never said I was correct to compare these analogies, I
just put them forward for thought knowing that when the sets are
assembled they are positioned to the north with the crt in a fixed
position and the yoke is then manipulated to its best angle tho it has
been known for T.V. pictures to be skewed by 3 degrees or so. Yup, I
did make some effort don't you think?
Art


Not much, just leaps from one thought to another without explanaion.

Jimmie