Reg, when I penned the thread beginnings I was trying to evoke
fresh thinking about the subject so as to challenge ideas that are spread by
plagurism in a similar way that the ballon is shown to demonstrate how
directivity /gain occurs.
Ham radio operators are lead to believe that the height above ground of
a beam's feed point determines the take off angle. It is true that it does
have an effect on the TOA, say 75 percent, when other actions are taken
to change the angle and 95 percent or so if no other actions are taken.
Thus if actions are taken to lower the TOA one can take advantage of
physical hops that were not available for a similar feed point height.
This is why I returned to the thread to dispute the statement that you
made regarding no amount of antenna waving can change the facts.
Regards from another indentured apporentice from the school of
Engineering and Navigation along side of the East India Docks
which was attended by many from the cable company further
down the river
Art







Edwards" wrote in message
...

"Reg Edwards" wrote
The elevation angle of a radio wave is not related to antenna
construction.


snip

BUT NO AMOUNT OF WAVING THE ANTENNA ABOUT WILL AFFECT THE ELEVATION ANGLE
OF
THE RADIO PATH.

snip.
----
.................................................. .........
Regards from Reg, G4FGQ
For Free Radio Design Software go to
http://www.btinternet.com/~g4fgq.regp
.................................................. .........

=========================================

Why should my answer to the question be altogether different to everybody
else's? Especially as I'm right.
\
Possibly because you were addressing a different question




---
Reg.

John wrote:
Can someone tell me please an easy way to calculate the optimum angle of
radiation from a transmitting antenna over a given path on the HF bands
(160m - 10m)?

OK, I guess its all to do with the height of the reflective layer in play
and the distance of the QSO but I'd really appreciate some clues as to how
to work this out.

Try the propagation chapter in the ARRL Antenna Book.
--
73, Cecil http://www.qsl.net/w5dxp


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Cecil Moore wrote:
John wrote:
Can someone tell me please an easy way to calculate the optimum angle
of radiation from a transmitting antenna over a given path on the HF
bands (160m - 10m)?
OK, I guess its all to do with the height of the reflective layer in
play and the distance of the QSO but I'd really appreciate some clues
to how to work this out.

Try the propagation chapter in the ARRL Antenna Book.

That would be a very good introduction to modern software like W6ELPROP.
What it teaches you is that angles of arrival vary considerably, even
for one given path, for reasons ranging from time of day to time in the
11/22-year sunspot cycle.

Remember that the F-layer is constantly changing height, especially if
it's around around dawn and dusk at one of the reflection points. This
means that at certain times the propagation has to 'flip' from say
3-hop-F to 4-hop-F, so the angle will flip too. And don't forget the
E-layer, if that's there too.

W6ELPROP will actually tell you what propagation modes are the most
likely at various times of day... and the reality is *much* more
complicated than the simple pictures shown in older books.

The ARRL Antenna Book does rather assume that you can put up any antenna
you can dream of; in which case, it will help you design the optimum
system. Ideally, the antenna needs to be able to adapt to the needs of
the moment.

But for most of us, it's much simpler than that. We can never achieve
the low angles that are sometimes needed for some of the most important
paths, so it simply comes down to doing the best we can. "Adaptability"
comes down to possibly having a second-choice antenna... which at
certain times may turn out to be better.

But even if we can't actually *do* anything about it, it's better at
least to understand that arrival angles (or conversely, optimum launch
angles) are actually very variable.



--
73 from Ian G3SEK 'In Practice' columnist for RadCom (RSGB)
http://www.ifwtech.co.uk/g3sek

Looking at the ARRL Antenna book it seems that the angle of radiation is
pretty well fixed on the type of antenna.
"Ian White G3SEK" wrote in message
...
Cecil Moore wrote:
John wrote:
Can someone tell me please an easy way to calculate the optimum angle of
radiation from a transmitting antenna over a given path on the HF bands
(160m - 10m)?
OK, I guess its all to do with the height of the reflective layer in
play and the distance of the QSO but I'd really appreciate some clues to
how to work this out.

Try the propagation chapter in the ARRL Antenna Book.

That would be a very good introduction to modern software like W6ELPROP.
What it teaches you is that angles of arrival vary considerably, even for
one given path, for reasons ranging from time of day to time in the
11/22-year sunspot cycle.

Remember that the F-layer is constantly changing height, especially if
it's around around dawn and dusk at one of the reflection points. This
means that at certain times the propagation has to 'flip' from say 3-hop-F
to 4-hop-F, so the angle will flip too. And don't forget the E-layer, if
that's there too.

W6ELPROP will actually tell you what propagation modes are the most likely
at various times of day... and the reality is *much* more complicated than
the simple pictures shown in older books.

The ARRL Antenna Book does rather assume that you can put up any antenna
you can dream of; in which case, it will help you design the optimum
system. Ideally, the antenna needs to be able to adapt to the needs of the
moment.

But for most of us, it's much simpler than that. We can never achieve the
low angles that are sometimes needed for some of the most important paths,
so it simply comes down to doing the best we can. "Adaptability" comes
down to possibly having a second-choice antenna... which at certain times
may turn out to be better.

But even if we can't actually *do* anything about it, it's better at least
to understand that arrival angles (or conversely, optimum launch angles)
are actually very variable.



--
73 from Ian G3SEK 'In Practice' columnist for RadCom (RSGB)
http://www.ifwtech.co.uk/g3sek

Mike Coombes wrote:
Looking at the ARRL Antenna book it seems that the angle of radiation
is pretty well fixed on the type of antenna.

Talking about "the" angle (as if there was only one) is misleading
ourselves.

Every antenna has a *range* of angles over which it radiates (or
receives) the best. The aim is to make that coincide with the *range* of
angles over which signals are likely to arrive.

This is made very clear in the 18th edition of the Antenna Handbook
onwards. It presents arrival angles as a statistical range of
probabilities, over a spread of possible propagation conditions.

If you have only one antenna, then obviously you try to make its very
best radiation angle coincide with the most *likely* angle of arrival.
But it's a game of chance. Occasionally the angle may be very different
from the most likely value, so you have to accept that you're going to
be some dB down... or dead in the water. And that is where having a
choice of different antennas really scores.


--
73 from Ian G3SEK 'In Practice' columnist for RadCom (RSGB)
http://www.ifwtech.co.uk/g3sek

"John" wrote in message ...
Can someone tell me please an easy way to calculate the optimum angle of
radiation from a transmitting antenna over a given path on the HF bands
(160m - 10m)?

OK, I guess its all to do with the height of the reflective layer in play
and the distance of the QSO but I'd really appreciate some clues as to how
to work this out.

John, to get some more insight in this, I could suggest to take a look
at
http://elbert.its.bldrdoc.gov/pc_hf/hfwin32.html.

I must admit however that it will require some learning-effort.

If you found the angle of interest, you could then use any antenna
modelling package to determine the antenna height needed for the
frequency used. Or use HFTA for none-flat/sloping surfaces.

Arie.

hello Reg I've downloaded some of your programs.
very helpful, thank you very much.
Were you a maths teacher or something like in a past life?

Excellent programs, from Reg for free...

http://www.btinternet.com/~g4fgq.regp

hello Reg I've downloaded some of your programs.
very helpful, thank you very much.
Were you a maths teacher or something like in a past life?

Excellent programs, from Reg for free...

http://www.btinternet.com/~g4fgq.regp

=================================

Not having an Eastern religion I have no recollection of a past life. But
the nearest I ever got to being a teacher in my present life was to teach
myself after the age of 14. It all happened purely by chance.

Although in the last few years of my career I did present, by invitation,
some one-day lectures to international audiences on the subject of how to
locate faults on oceanic submarine cables. And even in those far-off days,
when the repair ship captain chose to go 1/4-speed ahead and grapple for the
cable, depended on what he had had for breakfast. I understand cables now
contain optical-fibers but still contain a few copper wires for fault
location purposes.

But submarine telephone cables were a small part of my career. However they
did introduce me to transmission lines and communications in general. My
first connection with radio began, indirectly, a few years earlier, during
WW2, when I was a mechanical engineering apprentice in the tool-room and
machine shop of a well-known electric-motor manufacturer.
British-Thompson-Houston.

At the age of 16, while high explosives and incendiary bombs were falling on
the industrial City of Birmingam*, I set-up and operated precision lathes
and millers and broaches and shapers to manufacture what appeared to me to
be very small electric motors. (As distinct from anything up to 1000
horse-power motors and generators which was normal production.)

Having joined the RAF in 1943 as a radar technician, in 1944, by chance, I
came across these small electric motors once again. Actually, the articles
I had helped to manufacture were top-secret selsyns to be used to
synchronise airborne Radar plan-position indicating screens with their
respective airborne, rotating parabolic antennas.

The radar equipment was installed in Lancaster bombers, the most efficient
of the RAF's killing machines. The fire storms on German cities, almost as
good as the gas chambers, were more efficient than the Hiroshima and
Nagasaki weapons of mass-destruction. It just took a few hours longer.

The results of the latter weapons, in 1945, I witnessed and spoke to the few
survivors while wearing my blue RAF uniform. There were no signs of
animosity. The Japanese, an ancient educated and civilised people, were as
polite to me as a sort of tourist, thousands of miles from my home in
Birmingham (which they immediately recognised from a map sketched on the
back of a cigarette packet) as they were to each other.

My programs and Mathematics. There's very little advanced mathematics in my
programs. My arithmetic is entirely self-taught. But there's no two ways
about it - maths is either all right or all wrong. And either way it can
eventually be proved. That's the beauty of it.

University professors write books on it, plagiarise each other, and make a
living under false pretences - but they add nothing except something
illogical and misunderstood (usually a language problem) to haggle about in
newsgroups. Same applies to radio. KISS.

The key to my programs is a logical understanding of distributed electrical
circuits. It's just elementary electrical engineering. If YOU can understand
them then you are well away. If you can't understand them then its because I
have been deficient in my introductory notes.

Your comment on the 'excellence' of my programs is appreciated. But bear in
mind, regarding quality, I have never claimed them to be numerically more
accurate than needed for the purpose intended - whatever that may be.

==============================

*On the same night as the infamous air raid on Coventry, a greater weight of
bombs fell on the City of Birmingham and the industrial Black Country. Three
days later fires were still burning in the adjacent town of West Bromwich.
(These days West Bromwich is better noted for its football team.)

But Coventry, the City of Three Spires, three cathedrals, and Lady Godiva,
was the greatest concentration of war factories in the UK. Tanks, guns,
aircraft engines, fire pumps, motor vehicles, communications equipment were
all being made in the city, all intermingled with inflammable medieval
buildings to be ravaged by fire in the raid. Most of the human casualties
were due to a single bomb - a direct hit on an air-raid shelter.

Incidentally, the 3000 MHz, 50 KW, Cavity Magnetron had just been invented
by Randall and Boot in the Birmingham University laboratories which were
themselves surrounded by large factories, under air attack, such as the well
known Austin motor vehicle and the Aerial motorcycle works.

The magnetron was used to guide Lancaster bomber crews to their unfortunate
targets where 10's of thousands of the inhabitants were burned alive, their
husbands and brothers dying on the Eastern Front against Russian rockets and
T54 tanks.

The magnetron was also used in the 5-year long Battle of the North Atlantic.

On the average a 10,000-ton food and munitions ship was sunk every day. More
than 100,000 merchant seamen, civilians, without military pensions for their
families, lost their lives in Davy Jones locker.

Towards the end of the war German submarine crews were on suicide missions.
U-boat commanders, once detected by radar, had little option but to stay on
the surface, uncover the guns, and fight it out. To submerge they were dead
by depth charges. Their precise locations being located and remembered by
airborne radar.

These days we have other forms of suicide. There are people who are living
such enforced miserable lives and in such oppressed conditions they prefer
to sacrifice their own lives in the hope of improving the future lives of
their families and their decendents.

Citizens of the United States, and others, ask yourselves WHY?

Tonight I'm on a Bordeaux Claret. Vive L'entente Cordiale.
----
Reg, Amateur Radio, G4FGQ

Reg, G4FGQ wrote:
"The fire storms on German cities, almost as good as gas chambers, were
more efficient than Hiroshima and Nagasaki weapons of mass-destruction."

Just to quibble a bit, the atomic bomb was efficient for an explosive of
its weight, equal to megatons of conventional explosives. My ship
carried some of the first occupation forces into the Nagasaki area which
I got to see. Our ship`s company armed ourselves and marched through
town to see if it were safe to disgorge our soldiers there. Our captain
outranked the army commander. The Japs were meek. They had suffered real
stun and awe. Near ground zero about all that was left were fire-proof
safes.

News here this week included a story on a German memorial celebration of
the 60th anniversary of the destruction of Dresden by a single
American/British airaid which produced one of those firestorms with
massive conventional explosives and incendiary devices. The Germans
don`t want to forget it.

The raid was of course OK as it was retribution for such destruction of
English and other European cities.

Best regards, Richard Harrison, KB5WZI

"Richard Harrison" wrote in message
...
Just to quibble a bit, the atomic bomb was efficient for an explosive of
its weight, equal to megatons of conventional explosives.

To quibble a bit more, the "Little Boy" uranium atomic bomb dropped on
Hiroshima weighed about four to five tons and was the equivalent of about
10 to 15 kilotons of conventional (TNT) explosives. The "Fat Man"
plutonium bomb dropped on Nagasaki had the equivalent of about 20 to 22
kilotons of conventional explosives. The variance in numbers is based on
quotes from different sources.