On 11/13/2014 6:12 PM, wrote:
FBMboomer wrote:
On 11/12/2014 1:50 PM, gareth wrote:
It is a truism that short antennae are poor inefficient radiators, and no
amount of infantile bluster by Americanoramuses will change that.

The truth does not need the violence of abuse to force its way down
people's throats.



A perfect example is a G5RV on 75 meters. They suck. When someone joins
our group rag chew on 75, and they have a poor signal, The first thing I
ask is "Are you using a G5RV". We all have a chuckle when they answer
yes and then ask how we knew. :-)


False logic. You don't know how many people with good signals are using
G5RV's, because you only ask those with poor signals.

Trying to prove with math that short antennae work as well as say a 1/2
wave dipole may give someone great sport. However, in the real world,
short antennae suck big time. I have been an American for most of my
life. Please do not paint us all with the same brush.

Yes and no. Depending on their design, short antennas can be very
efficient. See
http://www.futurity.org/radio-wave-c...phones-801322/ for an
example.

But others are correct. The antenna itself is an efficient radiator;
it's the matching network that lowers *antenna system* efficiency.


Any dipole type antenna will suck on 75M if mounted less than about
100 feet, or about .4 wavelengths. Below that you are warming clouds.


So now it's 100 feet? It used to be 60 feet. But I have proof that is
not the case. So do a lot of other hams I know.

Your "facts" are for an idealized installation. Reality is much
different, and will never get the ideal specifications you claim.

snip

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Rob wrote:
wrote:
FBMboomer wrote:
On 11/12/2014 1:50 PM, gareth wrote:
It is a truism that short antennae are poor inefficient radiators, and no
amount of infantile bluster by Americanoramuses will change that.

The truth does not need the violence of abuse to force its way down
people's throats.



A perfect example is a G5RV on 75 meters. They suck. When someone joins
our group rag chew on 75, and they have a poor signal, The first thing I
ask is "Are you using a G5RV". We all have a chuckle when they answer
yes and then ask how we knew. :-)

Trying to prove with math that short antennae work as well as say a 1/2
wave dipole may give someone great sport. However, in the real world,
short antennae suck big time. I have been an American for most of my
life. Please do not paint us all with the same brush.

Any dipole type antenna will suck on 75M if mounted less than about
100 feet, or about .4 wavelengths. Below that you are warming clouds.

But that is actually very useful on the low bands!

Not for working "DX", but when you want to run a roudtable in an area
it works very well, especially when not in full summer daylight.

There are several of these groups active here, and it provides a
convenient coverage area for our language area, much larger than what
you achieve on e.g. 2 meters with typical vertical omni antennas mounted
on rooftops.

Yes, if what you want to achieve is local area coverage on HF, then
NVIS antennas work well for that.

The real problem is people throw around terms like "crappy", "sucks",
and "poor performer" without defining what it is they are trying to
achieve.



--
Jim Pennino

Jerry Stuckle wrote:
On 11/13/2014 6:12 PM, wrote:
FBMboomer wrote:
On 11/12/2014 1:50 PM, gareth wrote:
It is a truism that short antennae are poor inefficient radiators, and no
amount of infantile bluster by Americanoramuses will change that.

The truth does not need the violence of abuse to force its way down
people's throats.



A perfect example is a G5RV on 75 meters. They suck. When someone joins
our group rag chew on 75, and they have a poor signal, The first thing I
ask is "Are you using a G5RV". We all have a chuckle when they answer
yes and then ask how we knew. :-)


False logic. You don't know how many people with good signals are using
G5RV's, because you only ask those with poor signals.

Trying to prove with math that short antennae work as well as say a 1/2
wave dipole may give someone great sport. However, in the real world,
short antennae suck big time. I have been an American for most of my
life. Please do not paint us all with the same brush.

Yes and no. Depending on their design, short antennas can be very
efficient. See
http://www.futurity.org/radio-wave-c...phones-801322/ for an
example.

But others are correct. The antenna itself is an efficient radiator;
it's the matching network that lowers *antenna system* efficiency.


Any dipole type antenna will suck on 75M if mounted less than about
100 feet, or about .4 wavelengths. Below that you are warming clouds.


So now it's 100 feet? It used to be 60 feet. But I have proof that is
not the case. So do a lot of other hams I know.

Your "facts" are for an idealized installation. Reality is much
different, and will never get the ideal specifications you claim.

For a dipole over average ground:

Height Gain @ Elevation
lambda

0.1 3.89 90
0.15 5.55 90
0.2 5.95 90
0.25 5.81 62
0.3 5.80 48
0.35 6.00 40
0.4 6.38 35
0.45 6.86 31
0.5 7.41 28
0.55 7.76 25
0.6 7.87 23
0.65 7.76 21
0.7 7.54 20
0.75 7.30 18
0.8 7.16 17
0.85 7.15 16
0.9 7.26 15
0.95 7.47 15
1 7.71 14

At 75M .4 lambda is about 100 feet.

Generally for DX a takeoff angle of 30 degrees or less is the rule of
thumb for best general performance.

Of course the antenna still "works" at other heights, but if DX is what
you want to achieve, then best results, on the average over average
ground, the antenna will work best for that at a height of .5 lambda
or better.

Now is you happen to be in a salt water marsh surrounded by 100 foot
tall steel blimp hangers, your results may vary.


--
Jim Pennino

wrote in message
...
But others are correct. The antenna itself is an efficient radiator;
it's the matching network that lowers *antenna system* efficiency.


Any dipole type antenna will suck on 75M if mounted less than about
100 feet, or about .4 wavelengths. Below that you are warming clouds.


So now it's 100 feet? It used to be 60 feet. But I have proof that is
not the case. So do a lot of other hams I know.

Your "facts" are for an idealized installation. Reality is much
different, and will never get the ideal specifications you claim.

For a dipole over average ground:

Height Gain @ Elevation
lambda

0.1 3.89 90
0.15 5.55 90
0.2 5.95 90
0.25 5.81 62
0.3 5.80 48
0.35 6.00 40
0.4 6.38 35
0.45 6.86 31
0.5 7.41 28
0.55 7.76 25
0.6 7.87 23
0.65 7.76 21
0.7 7.54 20
0.75 7.30 18
0.8 7.16 17
0.85 7.15 16
0.9 7.26 15
0.95 7.47 15
1 7.71 14

At 75M .4 lambda is about 100 feet.

Generally for DX a takeoff angle of 30 degrees or less is the rule of
thumb for best general performance.

Of course the antenna still "works" at other heights, but if DX is what
you want to achieve, then best results, on the average over average
ground, the antenna will work best for that at a height of .5 lambda
or better.

Now is you happen to be in a salt water marsh surrounded by 100 foot
tall steel blimp hangers, your results may vary.

At a given height wouldn't all simple horizontal antennas (halfwave dipole,
g5rv) have the same take off angle and be equal in that respect ? Say you
had a halfwave horizontal and replaced it with the g5rv at the same height
there shold not be any differance it the takeoff angle. If there is any big
differance in the signal , it would probably be the loss in the feedline
going to the 102 foot long antenna.

I have been tempted to put up a g5rv just to see what it would do. I have
an 80 meter dipole and also an OCF Carolina Windom at about the same heigth.
They are around 60 feet on the ends. There is usually not too much
differance in them except certain directions and distances. Then there can
be several S units at some directions. This is probably because they are at
right angles to each other.




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Ralph Mowery wrote:

wrote in message
...
But others are correct. The antenna itself is an efficient radiator;
it's the matching network that lowers *antenna system* efficiency.


Any dipole type antenna will suck on 75M if mounted less than about
100 feet, or about .4 wavelengths. Below that you are warming clouds.


So now it's 100 feet? It used to be 60 feet. But I have proof that is
not the case. So do a lot of other hams I know.

Your "facts" are for an idealized installation. Reality is much
different, and will never get the ideal specifications you claim.

For a dipole over average ground:

Height Gain @ Elevation
lambda

0.1 3.89 90
0.15 5.55 90
0.2 5.95 90
0.25 5.81 62
0.3 5.80 48
0.35 6.00 40
0.4 6.38 35
0.45 6.86 31
0.5 7.41 28
0.55 7.76 25
0.6 7.87 23
0.65 7.76 21
0.7 7.54 20
0.75 7.30 18
0.8 7.16 17
0.85 7.15 16
0.9 7.26 15
0.95 7.47 15
1 7.71 14

At 75M .4 lambda is about 100 feet.

Generally for DX a takeoff angle of 30 degrees or less is the rule of
thumb for best general performance.

Of course the antenna still "works" at other heights, but if DX is what
you want to achieve, then best results, on the average over average
ground, the antenna will work best for that at a height of .5 lambda
or better.

Now is you happen to be in a salt water marsh surrounded by 100 foot
tall steel blimp hangers, your results may vary.

At a given height wouldn't all simple horizontal antennas (halfwave dipole,
g5rv) have the same take off angle and be equal in that respect ? Say you
had a halfwave horizontal and replaced it with the g5rv at the same height
there shold not be any differance it the takeoff angle. If there is any big
differance in the signal , it would probably be the loss in the feedline
going to the 102 foot long antenna.

Yes.

It also, in general, applies to yagi antennas, though the numbers are
a bit different.

I have been tempted to put up a g5rv just to see what it would do. I have
an 80 meter dipole and also an OCF Carolina Windom at about the same heigth.
They are around 60 feet on the ends. There is usually not too much
differance in them except certain directions and distances. Then there can
be several S units at some directions. This is probably because they are at
right angles to each other.

Probably true.


--
Jim Pennino

On 11/14/2014 12:34 PM, wrote:
Jerry Stuckle wrote:
On 11/13/2014 6:12 PM, wrote:
FBMboomer wrote:
On 11/12/2014 1:50 PM, gareth wrote:
It is a truism that short antennae are poor inefficient radiators, and no
amount of infantile bluster by Americanoramuses will change that.

The truth does not need the violence of abuse to force its way down
people's throats.



A perfect example is a G5RV on 75 meters. They suck. When someone joins
our group rag chew on 75, and they have a poor signal, The first thing I
ask is "Are you using a G5RV". We all have a chuckle when they answer
yes and then ask how we knew. :-)


False logic. You don't know how many people with good signals are using
G5RV's, because you only ask those with poor signals.

Trying to prove with math that short antennae work as well as say a 1/2
wave dipole may give someone great sport. However, in the real world,
short antennae suck big time. I have been an American for most of my
life. Please do not paint us all with the same brush.

Yes and no. Depending on their design, short antennas can be very
efficient. See
http://www.futurity.org/radio-wave-c...phones-801322/ for an
example.

But others are correct. The antenna itself is an efficient radiator;
it's the matching network that lowers *antenna system* efficiency.


Any dipole type antenna will suck on 75M if mounted less than about
100 feet, or about .4 wavelengths. Below that you are warming clouds.


So now it's 100 feet? It used to be 60 feet. But I have proof that is
not the case. So do a lot of other hams I know.

Your "facts" are for an idealized installation. Reality is much
different, and will never get the ideal specifications you claim.

For a dipole over average ground:

Height Gain @ Elevation
lambda

0.1 3.89 90
0.15 5.55 90
0.2 5.95 90
0.25 5.81 62
0.3 5.80 48
0.35 6.00 40
0.4 6.38 35
0.45 6.86 31
0.5 7.41 28
0.55 7.76 25
0.6 7.87 23
0.65 7.76 21
0.7 7.54 20
0.75 7.30 18
0.8 7.16 17
0.85 7.15 16
0.9 7.26 15
0.95 7.47 15
1 7.71 14

At 75M .4 lambda is about 100 feet.

Generally for DX a takeoff angle of 30 degrees or less is the rule of
thumb for best general performance.

Of course the antenna still "works" at other heights, but if DX is what
you want to achieve, then best results, on the average over average
ground, the antenna will work best for that at a height of .5 lambda
or better.

Now is you happen to be in a salt water marsh surrounded by 100 foot
tall steel blimp hangers, your results may vary.



You ignore the fact this is an idealized environment. That is NEVER the
case in a real installation.

I have WAS on 75 SSB (from Iowa) with an inverted Vee. The top was only
50' in the air. And late at night in the wintertime I had pretty solid
communications over much of the continental U.S. (back in the late 70's
and early 80's).

Antennas NEVER work "as predicted" - and anyone who claims they do does
not understand antenna operation.

--
==================
Remove the "x" from my email address
Jerry, AI0K

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

"Jerry Stuckle" wrote in message
...
On 11/14/2014 12:34 PM, wrote:

You ignore the fact this is an idealized environment. That is NEVER the
case in a real installation.

I have WAS on 75 SSB (from Iowa) with an inverted Vee. The top was only
50' in the air. And late at night in the wintertime I had pretty solid
communications over much of the continental U.S. (back in the late 70's
and early 80's).

Antennas NEVER work "as predicted" - and anyone who claims they do does
not understand antenna operation.


Antennas 'always' work as predicted. People just don't always factor in
everything in the prediction. Just as I worked a station on 432 MHz with 25
watts to a 1/4 wave ground plane that was about 1000 miles away. Nice bit
of tropo that day.

I bet I could put up a g5rv at 30 feet on some rare country and get loads of
5/9 signals no mater how many times the calls had to be repeatd.



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El 14-11-14 19:12, Ralph Mowery escribió:
wrote in message
...
But others are correct. The antenna itself is an efficient radiator;
it's the matching network that lowers *antenna system* efficiency.


Any dipole type antenna will suck on 75M if mounted less than about
100 feet, or about .4 wavelengths. Below that you are warming clouds.


So now it's 100 feet? It used to be 60 feet. But I have proof that is
not the case. So do a lot of other hams I know.

Your "facts" are for an idealized installation. Reality is much
different, and will never get the ideal specifications you claim.

For a dipole over average ground:

Height Gain @ Elevation
lambda

0.1 3.89 90
0.15 5.55 90
0.2 5.95 90
0.25 5.81 62
0.3 5.80 48
0.35 6.00 40
0.4 6.38 35
0.45 6.86 31
0.5 7.41 28
0.55 7.76 25
0.6 7.87 23
0.65 7.76 21
0.7 7.54 20
0.75 7.30 18
0.8 7.16 17
0.85 7.15 16
0.9 7.26 15
0.95 7.47 15
1 7.71 14

At 75M .4 lambda is about 100 feet.

Generally for DX a takeoff angle of 30 degrees or less is the rule of
thumb for best general performance.

Of course the antenna still "works" at other heights, but if DX is what
you want to achieve, then best results, on the average over average
ground, the antenna will work best for that at a height of .5 lambda
or better.

Now is you happen to be in a salt water marsh surrounded by 100 foot
tall steel blimp hangers, your results may vary.

At a given height wouldn't all simple horizontal antennas (halfwave dipole,
g5rv) have the same take off angle and be equal in that respect ? Say you
had a halfwave horizontal and replaced it with the g5rv at the same height
there shold not be any differance it the takeoff angle. If there is any big
differance in the signal , it would probably be the loss in the feedline
going to the 102 foot long antenna.

You are right, if you use a G5RV that has no feedline radiation (both
ladder line and coaxial part), the shape of the H-plane elevation
pattern is the same, and practically the same for the E-field plane.


I have been tempted to put up a g5rv just to see what it would do. I have
an 80 meter dipole and also an OCF Carolina Windom at about the same heigth.
They are around 60 feet on the ends. There is usually not too much
differance in them except certain directions and distances. Then there can
be several S units at some directions. This is probably because they are at
right angles to each other.

The shape of the radiation pattern for an OCF (no feed line radiation)
at greater then twice the half wave frequency is different from that
of a originally center-fed half wave dipole. The current distribution
is different (you get phase reversals in the OCF antenna).

Just an example: When using an OCF at twice the half wave frequency,
it has no radiation in the H-plane (that is the plane perpendicular to
the wires, you get a 4-leaf pattern). A center-fed antenne has good
radiation in the H-plane at twice the half wave frequency. Of course
it has high input impedance, so one has to take care of the matching.

That means that if you have an OCF with its half wave frequency at
75m, it will not act as a good NVIS antenna at 40m.


--
Wim
PA3DJS
Please remove abc first in case of PM

Jerry Stuckle wrote:
On 11/14/2014 12:34 PM, wrote:
Jerry Stuckle wrote:
On 11/13/2014 6:12 PM, wrote:
FBMboomer wrote:
On 11/12/2014 1:50 PM, gareth wrote:
It is a truism that short antennae are poor inefficient radiators, and no
amount of infantile bluster by Americanoramuses will change that.

The truth does not need the violence of abuse to force its way down
people's throats.



A perfect example is a G5RV on 75 meters. They suck. When someone joins
our group rag chew on 75, and they have a poor signal, The first thing I
ask is "Are you using a G5RV". We all have a chuckle when they answer
yes and then ask how we knew. :-)


False logic. You don't know how many people with good signals are using
G5RV's, because you only ask those with poor signals.

Trying to prove with math that short antennae work as well as say a 1/2
wave dipole may give someone great sport. However, in the real world,
short antennae suck big time. I have been an American for most of my
life. Please do not paint us all with the same brush.

Yes and no. Depending on their design, short antennas can be very
efficient. See
http://www.futurity.org/radio-wave-c...phones-801322/ for an
example.

But others are correct. The antenna itself is an efficient radiator;
it's the matching network that lowers *antenna system* efficiency.


Any dipole type antenna will suck on 75M if mounted less than about
100 feet, or about .4 wavelengths. Below that you are warming clouds.


So now it's 100 feet? It used to be 60 feet. But I have proof that is
not the case. So do a lot of other hams I know.

Your "facts" are for an idealized installation. Reality is much
different, and will never get the ideal specifications you claim.

For a dipole over average ground:

Height Gain @ Elevation
lambda

0.1 3.89 90
0.15 5.55 90
0.2 5.95 90
0.25 5.81 62
0.3 5.80 48
0.35 6.00 40
0.4 6.38 35
0.45 6.86 31
0.5 7.41 28
0.55 7.76 25
0.6 7.87 23
0.65 7.76 21
0.7 7.54 20
0.75 7.30 18
0.8 7.16 17
0.85 7.15 16
0.9 7.26 15
0.95 7.47 15
1 7.71 14

At 75M .4 lambda is about 100 feet.

Generally for DX a takeoff angle of 30 degrees or less is the rule of
thumb for best general performance.

Of course the antenna still "works" at other heights, but if DX is what
you want to achieve, then best results, on the average over average
ground, the antenna will work best for that at a height of .5 lambda
or better.

Now is you happen to be in a salt water marsh surrounded by 100 foot
tall steel blimp hangers, your results may vary.



You ignore the fact this is an idealized environment. That is NEVER the
case in a real installation.

You ignore the fact this is modeled on an AVERAGE environment.

I have WAS on 75 SSB (from Iowa) with an inverted Vee. The top was only
50' in the air. And late at night in the wintertime I had pretty solid
communications over much of the continental U.S. (back in the late 70's
and early 80's).

Big whoop.

The post wasn't about how many QSL cards have been collected, it was
about antenna patterns.

Antennas NEVER work "as predicted" - and anyone who claims they do does
not understand antenna operation.

Any prediction is as good as the model used to make the prediction.

If one can not build a model that is accurate to about two digit accuracy,
then they shouldn't be trying to build models.


--
Jim Pennino

On 11/14/2014 3:49 PM, Ralph Mowery wrote:
"Jerry Stuckle" wrote in message
...
On 11/14/2014 12:34 PM, wrote:

You ignore the fact this is an idealized environment. That is NEVER the
case in a real installation.

I have WAS on 75 SSB (from Iowa) with an inverted Vee. The top was only
50' in the air. And late at night in the wintertime I had pretty solid
communications over much of the continental U.S. (back in the late 70's
and early 80's).

Antennas NEVER work "as predicted" - and anyone who claims they do does
not understand antenna operation.


Antennas 'always' work as predicted. People just don't always factor in
everything in the prediction. Just as I worked a station on 432 MHz with 25
watts to a 1/4 wave ground plane that was about 1000 miles away. Nice bit
of tropo that day.


The problem is - taking into consideration EVERYTHING which could affect
it. Well nigh impossible - even the neighbor's chain link fence could
have an effect, for instance. That's why AM commercial radio stations
plan their antenna phasing for the desired pattern - but then have to
measure it almost always tweak the delay lines to get the exact shape
they want.

For instance - I remember one I worked at back in the 70's. It's
pattern was directly affected by moisture in the air and, to a certain
effect, ground. You could see the difference in tuning for the
transmitters between a very foggy night and a clear one. This also
caused a change in the radiated pattern. Fortunately it was still with
the limits set by the FCC, or we'd have to rephase the towers with every
change to the weather. BTW - the main cause was the ground plane
(circles of wires around each tower with radials from the tower out -
and silver soldered where ever the wires crossed) was pretty old, and
subject to changing weather conditions.


I bet I could put up a g5rv at 30 feet on some rare country and get loads of
5/9 signals no mater how many times the calls had to be repeatd.


I highly suspect you could!



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==================
Remove the "x" from my email address
Jerry, AI0K

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