Reg wrote:
"If you can`t be heard at 1000 miles or more using a dipole, you are
more likely to be heard using a vertical regardless of what the other
fellow is using to receive."

That must not always be the case. Otherwise all the shortwave broadcast
stations I`ve worked in, and seen for that matter, would not use
horizontal antennas. They have no way of knowing what their audience
will use for antennas, and it does not make much difference as following
ionospheric reflection, all wave polarizations are available and may be
received.

At the equator, a time zone is about 1000 miles wide. at the poles (a
bad place for shortwave propagation) the width of a time zone is
insignificant. All the stations I refer to are in the temperate zone and
their targets are likely 1000 miles or so away, though some targets of
some stations are only a few hundred miles away.

Antennas at these shortwave broadcast stations are a product of studying
successful antennas and carefully designing new antennas anf testing
their performance in and around their intended targets. They are proved
to be effective.

Why would a vrtical antenna be better?

From Arnold B. Bailey`s giant antenna catalog in his "TV and Other
Receiving Antennas", the free-space gain is the same for a ground plane
as it is for a center-fed 1/2-wave dipole. An antenna`s proximity to the
earth may change the balance between horizontal and vertical antennas.

Terman writes on page 886 of his 1955 edition:
"Consider an antenna that is far enough from ground so that the total
power radiated by a given set of antenna currents is independent of the
presence of the ground. Then a ground reflection that reinforces the
main lobe will double the field strength of the main lobe, and so will
increase directive gain of the antenna system by a factor of 4. This
condition corresponds to an antenna height great enough to make the
mutual impedance between the antenna and its image small (see page
894).With horizontally polarized systems this will be the case if the
center of the antenna is at least one wavelength above ground; with
vertically polarized systems it is true even at lower heights.

However. when the antenna is sufficiently close to the ground the effect
of the ground reflection is to cause the directive gain to differ from
4. Thus , for a vertical doublet close to the ground, the directive gain
is twice the free-space value, since the presence of the ground does not
alter the directional pattern and there is no energy radiated in the
direction of the hemisphere occupied by the ground. In contrast, the
directive gain of a horizontal antenna very close to the ground can be
more than 4 as compared with the same antenna in free space, as
discussed below in connection with Fig. 23-36."

Seems horizontal antenna users are not fools after all.

Best wishes, Richard Harrison, KB5WZI

wrote:
This is an early stage of the experiment, but
I believe that there is a lot to say with the lower noise on the
horizontal antenna station


Probably has a lot to do with the particular sites
though. It's quite possible to be near a noise source
that is mainly vertical polarized. In a case like that, it's
possible it could be a problem.

Agreed.



But I never saw the difference
in noise levels you are seeing. At the worst, I might see
appx 2 S units, but sometimes it might only be one, or
even other times , nearly no difference at all. Most of
the noise I would see at this location is power line noise.

Tonight it is about 2 S units different. Also remember that I don't
have the two S-meters calibrated against each other


It seems to effect both horizontal and vertical nearly equally.
Probably cuz much is radiated by horizontal power lines.
I've never tested it, but I think if you are in a noiseless location,
the difference would be fairly small as far as meter readings
just measuring the average atmospheric noise.

I suspect so also. Maybe some day I'll test that out. The Butternut can
be removed and remounted pretty easily. There is a low noise area where
we have FD. Maybe I'll haul the vertical out there some weekend.

The reason I
say this is because sometimes I would see little difference in
noise between the two. But other times I might see more.
But you could see small differences just from the increase in
strength of dx signals. IE: if you had T-storms 1500 miles away,
it's quite likely the vertical will receive them stronger than the
horizontal due to the normal operation of the antennas.
Anyway, I don't totally consider what you see as the norm. "4 s units"
You probably have a local vertical noise source nearby. If it's power
line, etc, you might be able to track it down and get it fixed.
I'd be curious to see if you see the same 4 S unit noise difference
over a period of time. Like I say, mine would vary. But noise
never was much of a concern on mine. Never gave it much thought
at all. Kinda weird too being I'm in a big city, in a residential area.

Being mine was elevated at 36 ft at the base, I also had a pretty
good line of sight to any potential noise sources.
The tip of the radiator was at about 68 ft. As far as the VE being
better on the wire, that's probably fairly normal, being he wasn't dx.

Also, as a final note, while your butternut with 20 radials is ok, it
still
isn't quite up to the performance I saw with mine at 36 ft, using a
full size antenna. So I saw a larger signal increase on the dx than you

I bet. Mine was appx equal to a full length monopole with 60 radials,
if ground mounted. I'd have to look, but my ground may be a bit better
too. I'm right on the edge of being in a "30" zone. Of course, raising
efficiency raises s/n equally, but I noticed that I never saw the same
performance I had with the ground plane, when I ran the same full size
vertical on the ground with 32 radials. That antenna was about equal
to my dipoles at 1500 miles. Maybe a small bit better, but not any
2 S units worth like the GP was. So regardless of some saying the
number of radials is not too important, it must be, if you want the
best
performance. Sure made a difference here...

I'll be putting out more as time allows. The old back just doesn't
allow me to run more than about 5 at a time - too much Ice Hockey taking
it's toll! 8^)



Either that, or elevating it above the surroundings makes the
difference.
Myself, I think it's about 75% the first, and 25% the second...
Elevating
the antenna for sure increased my local ground wave. I could work 50
miles away ground wave easy. I'd have cases in the daytime where I'd
lose locals due to the band stretching out. But I could still nail them
at
S 9 using the GP, where the dipole would be hard to read backscatter.
Of course, if the band was open short, I'd be 10-20-30 over 9 on the
dipole
to the same location.

One thing that I am seeing is that different signals originating from
different locations are coming in at different strengths on the two
radios with the different antennas. This is fascinating. I've been
listening tonight to a VE, a Pennsylvania ham, and another from South
America.

I suppose that a lot of hams may be used to this, but I find it very
cool - I suppose that the different signals coming in at different
angles are "caught" by the different antennas differently. I gotta get
these two meters calibrated against each other.

Anyway, I guess you gotta use what works, but I don't think it's
totally
normal to see a huge difference in noise between vertical and
horizontal
unless something local is the culprit.

Could be a local problem - that one is harder for me to troubleshoot. I
would say that the noise is probably not power line source. It is a sort
of crashing noise. Almost like lightning noise, but occurring more
often, and less powerful. Could be southern hemisphere lightning storms?

- 73 de Mike KB3EIA -

On Thu, 02 Feb 2006 21:57:47 -0500, Mike Coslo
wrote:


But here is the interesting thing. On the horizontal antenna, the
listening is a whole heckava lot more pleasant. Another item of interest

Mike, you will be aware that a lot of commercial HF amateur
transceivers have two HF antenna sockets which can be selected from
the front panel. I have always wondered why they do not support a mode
of tx on Ant-1, rx on Ant-2 to conveniently support the very
configuration you are using.

Owen
--

Mike Coslo wrote:
. . .
I gotta get
these two meters calibrated against each other.
. . .

If you don't have a signal generator with variable output, connect the
two feedlines through a DPDT switch so it swaps the antenna to each
receiver when you switch it back and forth. Write down the meter reading
on each receiver for the same signal from the same antenna. It probably
won't take long to accumulate a decent cross reference.

Of course, you still won't have a clue as to how many dB each meter unit
represents. That'll take an investment of a few dollars and an evening
to make a step attenuator.

Roy Lewallen, W7EL

Owen Duffy wrote:
On Thu, 02 Feb 2006 21:57:47 -0500, Mike Coslo
wrote:



But here is the interesting thing. On the horizontal antenna, the
listening is a whole heckava lot more pleasant. Another item of interest


Mike, you will be aware that a lot of commercial HF amateur
transceivers have two HF antenna sockets which can be selected from
the front panel. I have always wondered why they do not support a mode
of tx on Ant-1, rx on Ant-2 to conveniently support the very
configuration you are using.

I'm inclined to agree. I guess I'll have to build a switching box.
Shades of olde time separate transmit/receive rigs!

- 73 de Mike KB3EIA -

On Sat, 04 Feb 2006 03:26:46 -0800, Roy Lewallen
wrote:


represents. That'll take an investment of a few dollars and an evening
to make a step attenuator.

A greatly overlooked item of test equipment.

I recall advising a ham to buy a HP355 step attenuator so that he
could quantify the level of interference from nearby power leaks and
build a prime facie case for non compliance with emission standards.

Although he had just winged at length about his $20,000 plus
investment in a tower and VHF/UHF antennas, more on radios, etc... he
baulked at spending a $100 on something as unexciting as a step
attenuator. This was an opportunity to learn a little more about
predicting path loss than a $100 burden.

As part of my FSM project for measuring BPL emissions, I went
searching the net for kits for RF step attenuators, and all that I
found were kits that had gone obsolete, no longer available. Today it
should be a piece of cake to do a low cost kit with miniature
switches, precision surface mount resistors etc... but we as a
community are apparently not sufficiently interested in quantifying
things these days.

Owen
--

Owen Duffy wrote:
. . .
As part of my FSM project for measuring BPL emissions, I went
searching the net for kits for RF step attenuators, and all that I
found were kits that had gone obsolete, no longer available. Today it
should be a piece of cake to do a low cost kit with miniature
switches, precision surface mount resistors etc... but we as a
community are apparently not sufficiently interested in quantifying
things these days.

A step attenuator which is completely adequate for HF and can easily
resolve 1 dB can be made from a few cheap slide switches, some PC board
material, and a handful of ordinary 5% quarter watt resistors. Detailed
instructions can be found in numerous sources, including the Web -- a
Google search brought a large number of hits, the first of which was
http://www.arrl.org/tis/info/pdf/9506033.pdf. But I'm afraid that this
level of homebrewing is beyond the interest if not the ability of the
majority of today's amateurs.

Roy Lewallen, W7EL

"Owen Duffy" wrote

but we as a community are apparently not sufficiently interested
in quantifying things these days.
==========================================

"When you can measure what you are speaking about and express it in
numbers you know something about it. But when you cannot measure it,
when you cannot express it in numbers, your knowledge is of a meagre
and unsatisfactory kind. It may be the beginning of knowledge but you
have scarcely in your thoughts advanced to the state of science."

: William Thomson, Lord Kelvin, 1824-1907.
==========================================

Arithmetic is not taught in Western schools and universities any more.
Even teachers are innumerate!
----
Reg.

Tnxs for that Reg

What is the generally accepted "number" in either S points or dB of
employing horizontal instead of vertical for noise reasons? Obviously it
would vary greatly but any idea you have would be helpful. I would also
like to get an idea how "critical" it is to make sure ones antenna truly
is horizontal (eg not an inverted V or quad loop) if noise is the
greatest concern.

One would assume you also get a similar affect of "less horizontal
noise" from the actual noise source for the same reason. eg power lines
radiate well upwards but not so well in groundwave.

Cheers Bob W5/VK2YQA

Reg Edwards wrote:

Local noise is stronger in terms of milli-volts per meter than distant
noise for obvious reasons. It is nearer and man-made.

"Bob Bob" wrote -
Tnxs for that Reg

What is the generally accepted "number" in either S points or dB of
employing horizontal instead of vertical for noise reasons?

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

Bob,

First of all we must entirely disregard the opinions of individuals
who may be located in high or low noise districts, areas or regions. I
myself live in an industrial, densely populated, area near to a
factory with a dozen electrical arc welding machines. Others live out
in the wilderness, isolated from modern, electrical noise generating
civilisation.

There exist statistics of AVERAGE field strength noise levels
experienced in cities, small towns and in the open countryside. I have
forgotten where to find such statistics but Google may help.

The statistics depend very much on frequency. They vary greatly
between ELF and HF. Noise levels decrease by crudely 10 dB or 20 dB
per octave or decade increase in frequency.

Furthermore, at ELF and VLF, noise propagates to far greater distances
than at HF. There are always continuous world-wide electrical storms
somewhere on the Earth's surface.

At 10 KHz noise levels may be several hundred milli-volts per meter.
At 7 MHz they may be microvolts per meter. At 30 MHz they are of the
order of the internal receiver noise.

The noise level indicated by your S-meter is a function of the size of
the antenna relative to wavelength and antenna efficiency. It can be
crudely calibrated in terms of micro-volts per metre using a little
arithmetic. Learn how to estimate.

In my own experience (which as I say should be disregarded) the
difference in noise level between a horizontal dipole and a vertical
is about one or two S-points on the 160 metre band. (Or a difference
of 6 or 12 dB.)

On the other hand, distant stations come in stronger using a 150-feet,
vertical (inverted-L) than they do on a dipole. Not that I have ever
used the two types of antenna simultaneously. It's just my opinion.
So I prefer the inverted-L. In general, the signal to noise ratio is
better and there is less fading. One hop instead of two, via the
F2-layer, at night, using a dipole?
----
Reg, G4FGQ