I'm proposing to build a new multi-band HF antenna. Previously I used simple
relatively low (8mtr) dipole (28mtr total length) feed with ladder line and
matched with a Z-Match tuner. Worked ok, but was useless for DX.
My proposed antenna is to be vertical (7mtr radiator) to be used on bands
from 10mtr to 30mtr.
I have heard that vertical antennas are more susceptible to noise!

I'm keen to hear this groups view on the noise issue and generally how
verticals are regarded as a DX antenna. Also keen to hear of personal
experiences with vertical antennas on HF.

Regards

Peter

http://members.optushome.com.au/vk6ysf/vk6ysf/main.htm

In . au "Peter"
wrote:

I'm keen to hear this groups view on the noise issue and generally how
verticals are regarded as a DX antenna. Also keen to hear of personal
experiences with vertical antennas on HF.

I've had a Cushcraft R5 vertical up on the roof since 1991 and have
worked 214 countries with 196 confirmed, mostly on CW, never running
more than 100 watts, with a very, very low-effort operation.

Things have been very tough the past several years with the lack of
sunspots though; watching the traffic on the DX clusters, it's obvious
that folks with better antennas are working people I can't even hear. On
the other hand, if I can hear them, I can usually work them.

As far as noise is concerned, I don't have anything other than a (very)
low 40m dipole to compare with, and the dipole is a lot noisier. I'm in
the city, on a very small lot, surrounded by other homes and the power
lines are about 60' away from the vertical and at about the same
height. The far end of the dipole is probably not more than 10' from
the power lines, both horizontally and vertically.

--
Bert Hyman St. Paul, MN

Peter wrote:
I'm proposing to build a new multi-band HF antenna. Previously I used simple
relatively low (8mtr) dipole (28mtr total length) feed with ladder line and
matched with a Z-Match tuner. Worked ok, but was useless for DX.
My proposed antenna is to be vertical (7mtr radiator) to be used on bands
from 10mtr to 30mtr.
I have heard that vertical antennas are more susceptible to noise!

I'm keen to hear this groups view on the noise issue and generally how
verticals are regarded as a DX antenna. Also keen to hear of personal
experiences with vertical antennas on HF.

Regards

Peter

http://members.optushome.com.au/vk6ysf/vk6ysf/main.htm



I'm thinking of getting one of these for the roof:

http://www.eham.net/reviews/detail/315

On Jan 12, 6:20*am, "Peter" wrote:
I'm proposing to build a new multi-band HF antenna. Previously I used simple
relatively low (8mtr) dipole (28mtr total length) feed with ladder line and
matched with a Z-Match tuner. Worked ok, but was useless for DX.

Shouldn't have been. Maybe not as good as a higher dipole, but
you should have been able to work some DX. I once used a 40m
dipole camping which was about 8 ft off the ground.
I tried it on 15m, and was working JA's left and right.
And 24 ft up is a good bit better than 8 ft.

My proposed antenna is to be vertical (7mtr radiator) to be used on bands
from 10mtr to 30mtr.
I have heard that vertical antennas are more susceptible to noise!

No. There is no difference as far as the antenna. It depends on the
polarity of the noise source. If it's vertical, then yes, the vertical
would pick up more noise.
If the noise source was horizontal, which is often is these days,
then the dipole would receive more noise.
Many man made noise sources are vertical, but that's
no different than having a desired signal being vertical.
Noise is RF the same as any other signal, and follows the
same rules.
Being crossed polarized will generally give you about a
20 db loss in signal. That will apply the same no matter
if it's a desired signal, or noise.
This only applies to a local space wave, which is how
most noise arrives . It gets a lot more complicated for
sky wave, and usually means a good bit less difference
overall.
So don't worry about noise until it possibly becomes an
issue. It's also quite possible for the increase in signals
to be greater than the increase in noise when working
long paths where the vertical has an advantage over the
lower dipole.
They work real well for DX and also local space wave
coverage, which is fairly popular on 10m.
But I recommend an elevated antenna when using the
higher bands. I would not use a ground mount unless
I had no other choice.
The R5 mentioned is a good one for that application.
I'm wondering how you will feed a 21 ft radiator for
all bands using a home brew design. It's not as simple
as it might seem for proper operation if elevated.
The R5 is a "1/2 wave" type design that does not require
radials. It's pretty convenient.
But if you use a trapped 1/4 wave ground plane type of
scheme for all bands, you will need at least one ground
radial for band, and preferably at least two spaced 180
degrees apart. And that's just a minimum.
Most ground planes I use have at least four radials.

Peter,

I have heard that vertical antennas are more susceptible to noise!
I live in a residential area with a moderate amount of man-made QRN. My
antenna "farm" (which is more of a small garden ;-) includes horizontal
dipoles for 80 and 160 meters, and verticals on 40, 80 and 160. Using a
remote antenna switch, I can quickly select antenna orientation and easily
compare signal strength and QRN levels.

For signal strength, the horizontals are superior under 500 miles, but after
that the verticals kick in and are almost-always better at DX distances. In
fact, even IF the signal strength of DX stations were equal on both, the
fact that the verticals attenuate the local stations by over 20db is enough
of a selling point.

For QRN, I think the answer is like real estate: location, location,
location. My verticals are at the rear of the property and farthest away
from power lines and AC service to the house. The dipoles extend into the
front yard and are more susceptible to AC line noise. Although I also
expected the verticals to be "noisier", due to locations the dipoles are a
little - but barely - noisier than the verticals.

Hope this explanation helps,
--
-larry
K8UT
"Peter" wrote in message
. au...
I'm proposing to build a new multi-band HF antenna. Previously I used
simple relatively low (8mtr) dipole (28mtr total length) feed with ladder
line and matched with a Z-Match tuner. Worked ok, but was useless for DX.
My proposed antenna is to be vertical (7mtr radiator) to be used on bands
from 10mtr to 30mtr.
I have heard that vertical antennas are more susceptible to noise!

I'm keen to hear this groups view on the noise issue and generally how
verticals are regarded as a DX antenna. Also keen to hear of personal
experiences with vertical antennas on HF.

Regards

Peter

http://members.optushome.com.au/vk6ysf/vk6ysf/main.htm

Larry Gauthier (K8UT) wrote:
My verticals are at the rear of the property and farthest away
from power lines and AC service to the house. The dipoles extend into the
front yard and are more susceptible to AC line noise. Although I also
expected the verticals to be "noisier", due to locations the dipoles are a
little - but barely - noisier than the verticals.

It certainly depends upon location. At my previous QTH,
the horizontal dipole was, on the average, 2 S-units
quieter than the 40m vertical. I tracked the noise to
a 30 foot ground wire running down a power pole.
--
73, Cecil http://www.w5dxp.com

"Cecil Moore" wrote in message
...
Larry Gauthier (K8UT) wrote:
My verticals are at the rear of the property and farthest away from power
lines and AC service to the house. The dipoles extend into the front yard
and are more susceptible to AC line noise. Although I also expected the
verticals to be "noisier", due to locations the dipoles are a little -
but barely - noisier than the verticals.

It certainly depends upon location. At my previous QTH,
the horizontal dipole was, on the average, 2 S-units
quieter than the 40m vertical. I tracked the noise to
a 30 foot ground wire running down a power pole.
--
73, Cecil http://www.w5dxp.com

Thanks for the comments, which confirms most of what beleive was the case.

The QTH is Northam in Western Australia, about 80km east from Perth. All
other major population centres are DX.

The nearest distribution transformer is about 250metre away as is the 22kV
HV feeder with only 240/415V low voltage in my street, therefore noise
should be low from this source.

The only thing to do is build it see!

Cheers
--
Peter VK6YSF

Cecil,

Please tell me any more information you may have about the ground wire
running down the power pole. I did the exact same thing here. I found
most of my noise was being generated by this ground wire 3 blocks from
my house. Were you able to do anything about it?

Michael

Cecil Moore wrote:
Larry Gauthier (K8UT) wrote:
My verticals are at the rear of the property and farthest away from
power lines and AC service to the house. The dipoles extend into the
front yard and are more susceptible to AC line noise. Although I also
expected the verticals to be "noisier", due to locations the dipoles
are a little - but barely - noisier than the verticals.

It certainly depends upon location. At my previous QTH,
the horizontal dipole was, on the average, 2 S-units
quieter than the 40m vertical. I tracked the noise to
a 30 foot ground wire running down a power pole.

On Jan 13, 11:12*am, Michael wrote:


It certainly depends upon location. At my previous QTH,
the horizontal dipole was, on the average, 2 S-units
quieter than the 40m vertical. I tracked the noise to
a 30 foot ground wire running down a power pole.

I would think that means a bad connection somewhere near
that point. Could be the wire connection to ground itself,
or a bad part somewhere near that area, and the ground
wire was just acting as an antenna extension to the bad
part. Many parts can develop bad or leaky connections and
start to cause noise. It was a bad end connector once when
I had to call the power co.
Make sure the ground wire is actually connected to ground
well, and if it still makes noise, try banging the power pole with a
sledgehammer while listening on a portable radio.
If the noise changes, it's fairly close in that area.
Or if you use a radio with a directional antenna, you might be
able to get fairly close.
Once you get that close, nothing to do except bug the power
company.

I'm thinking of getting one of these for the roof:

http://www.eham.net/reviews/detail/315

That's my plan as the garage has a large surface area galvanized steel roof.


Peter VK6YSF

http://members.optushome.com.au/vk6ysf/vk6ysf/main.htm