HF Mobile - Grounding Antenna when stationary
 

As an avid 4WD SUV owner I do a lot of outback travelling (Austrlian
Deserts, Cape York, Kimberly Coast) and as such have a Barrett 950 HFradio
&Barrett 910 Autotune antenna installed for comms.

Would it be preferable when camped / stationary to earth the vehile to a
"ground" ground = what I am looking for is a better receive signal ?????

HF Mobile - Grounding Antenna when stationary
 

ORIGINAL MESSAGE:

On Sun, 7 May 2006 10:33:51 +0930, "OZUser"
wrote:

As an avid 4WD SUV owner I do a lot of outback travelling (Austrlian
Deserts, Cape York, Kimberly Coast) and as such have a Barrett 950 HFradio
&Barrett 910 Autotune antenna installed for comms.

Would it be preferable when camped / stationary to earth the vehile to a
"ground" ground = what I am looking for is a better receive signal ?????



*********** REPLY SEPARATOR ***********

Improving the ground will increase the received signal strength but
will also increase the background noise as well, so the signal to
noise ratio won't change much if any. In other words, no real
improvement.

However, an improved ground will improve your transmitted signal,
especially on the lower frequencies - 7MHz and down.

Best of all though, would be to string up a temporary dipole or
inverted vee.

Bill, W6WRT

HF Mobile - Grounding Antenna when stationary
 

OZUser wrote:

As an avid 4WD SUV owner I do a lot of outback travelling (Austrlian
Deserts, Cape York, Kimberly Coast) and as such have a Barrett 950 HFradio
&Barrett 910 Autotune antenna installed for comms.

Would it be preferable when camped / stationary to earth the vehile to a
"ground" ground = what I am looking for is a better receive signal ?????




NOPE!!

But changing to a larger antenna will certainly help.

HF Mobile - Grounding Antenna when stationary
 

On Sun, 07 May 2006 10:33:51 +0930, OZUser wrote:

As an avid 4WD SUV owner I do a lot of outback travelling (Austrlian
Deserts, Cape York, Kimberly Coast) and as such have a Barrett 950 HFradio
&Barrett 910 Autotune antenna installed for comms.

Would it be preferable when camped / stationary to earth the vehile to a
"ground" ground = what I am looking for is a better receive signal ?????

Switching to a Dipole antenna suspended from the trees would be a Major
step upward in performance.

Mobile antennas have very low efficiency, grounding them will not improve
that significantly relative to the dipole.

KD

HF Mobile - Grounding Antenna when stationary
 

OZUser wrote:
As an avid 4WD SUV owner I do a lot of outback travelling (Austrlian
Deserts, Cape York, Kimberly Coast) and as such have a Barrett 950 HFradio
&Barrett 910 Autotune antenna installed for comms.

Would it be preferable when camped / stationary to earth the vehile to a
"ground" ground = what I am looking for is a better receive signal ?????



What are the typical distances you want to cover?

Below 7 MHz and at distances in the hundreds of miles, relatively low,
horizontal antennas may perform better than a vertical whip, even if
only the same length as the whip.


Chuck

HF Mobile - Grounding Antenna when stationary
 

In article 1146965914.944527@teuthos, "OZUser"
wrote:

As an avid 4WD SUV owner I do a lot of outback travelling (Austrlian
Deserts, Cape York, Kimberly Coast) and as such have a Barrett 950 HFradio
&Barrett 910 Autotune antenna installed for comms.

Would it be preferable when camped / stationary to earth the vehile to a
"ground" ground = what I am looking for is a better receive signal ?????




Ever thought about using a Ballon or Kite Antenna? Very Good for open
areas, and excellent for MF and HF Portable operations.

Me

HF Mobile - Grounding Antenna when stationary
 

OZUser wrote:
As an avid 4WD SUV owner I do a lot of outback travelling (Austrlian
Deserts, Cape York, Kimberly Coast) and as such have a Barrett 950 HFradio
&Barrett 910 Autotune antenna installed for comms.

Would it be preferable when camped / stationary to earth the vehile to a
"ground" ground = what I am looking for is a better receive signal ?????



I do not believe anything will improve the receive on the antenna you
are using, what ever it may be. If you are going to be parked, put up
"stick dipole" just as high as you can. That will help recieve and
transmit.

Butch Magee KF5DE

HF Mobile - Grounding Antenna when stationary
 

"Dave" wrote in message
...
OZUser wrote:

As an avid 4WD SUV owner I do a lot of outback travelling (Austrlian
Deserts, Cape York, Kimberly Coast) and as such have a Barrett 950
HFradio
&Barrett 910 Autotune antenna installed for comms.

Would it be preferable when camped / stationary to earth the vehile to a
"ground" ground = what I am looking for is a better receive signal ?????


NOPE!!
But changing to a larger antenna will certainly help.


Even if you went to the trouble of pounding in a 3 meter (8 ft) ground rod,
or laid out somewhere between five and 40 radials, the answer would still be
NOPE. As stated in other posts, the loaded mobile antenna is in-efficient
to begin with.

73, Steve, K9DCI

Well, knowing RF, it 'might' make a measurable difference (small amount),
but probably not a practical difference (many dB).

HF Mobile - Grounding Antenna when stationary
 

Some interesting responses you have received. I think however something
important has been missed.

On HF frequencies the received signal level is unimportant. What is
important is the "largest difference" possible between the signal level
and the noise level. In many cases improving an antenna tends to
increase both noise and signal received by equal amounts amounts. (I
should point out that this improvement does help transmitting though as
at the other end you become a stronger signal relative to noise) A
ground improvement in your case may reduce some losses but wont affect
the S/N.

So ask yourself what you would do to increase the S/N ratio. A directive
antenna may help, reducing local noise (like from generators etc) will
too. I would guess that given you are mobile your options are limited.
There have also been suggestions already about other antenna systems to
try. If however RX S/N is the most important to you I would try a
magloop for receive and a dipole or 1/4 wave GP for transmit!

Cheers Bob VK2YQA

OZUser wrote:
As an avid 4WD SUV owner I do a lot of outback travelling (Austrlian
Deserts, Cape York, Kimberly Coast) and as such have a Barrett 950 HFradio
&Barrett 910 Autotune antenna installed for comms.

Would it be preferable when camped / stationary to earth the vehile to a
"ground" ground = what I am looking for is a better receive signal ?????

HF Mobile - Grounding Antenna when stationary
 

On Tue, 09 May 2006 12:41:59 -0500, Bob Bob wrote:
OZUser wrote:
As an avid 4WD SUV owner I do a lot of outback travelling (Austrlian
Deserts, Cape York, Kimberly Coast) and as such have a Barrett 950 HFradio
&Barrett 910 Autotune antenna installed for comms.

Would it be preferable when camped / stationary to earth the vehile to a
"ground" ground = what I am looking for is a better receive signal ?????

Some interesting responses you have received. I think however something
important has been missed.

Yes, indeed. Some good fashioned old amateur radio experimenting.

[Top Posting corrected]
Jonesy W3DHJ

HF Mobile - Grounding Antenna when stationary
 

Korbin,
I have just done a heap of experimenting on 80m using a Terlin Outbacker
"Outreach" mobile whip.
I found that it made none or little difference when using 4 x 1/4 wavelength
radials.
I then used a 33 ft fibreglass extendable pole with a dipole attached,
certainly and naturally it outperformed the mobile whip.
I made up a full wave loop on 80m, slung it vertically between 2 large
trees, and found it out performed the dipole, mainly because of the noise
level was lower than either the mobile whip or the dipole.
On receive the full wave loop was the best, followed by the inverted vee and
lagging way behind was the mobile whip.
my 2 cents worth.
John

"Korbin Dallas" wrote in message
news:Uem7g.54594$Eh4.50096@trnddc01...
: On Sun, 07 May 2006 10:33:51 +0930, OZUser wrote:
:
: As an avid 4WD SUV owner I do a lot of outback travelling (Austrlian
: Deserts, Cape York, Kimberly Coast) and as such have a Barrett 950
HFradio
: &Barrett 910 Autotune antenna installed for comms.
:
: Would it be preferable when camped / stationary to earth the vehile to a
: "ground" ground = what I am looking for is a better receive signal ?????
:
: Switching to a Dipole antenna suspended from the trees would be a Major
: step upward in performance.
:
: Mobile antennas have very low efficiency, grounding them will not improve
: that significantly relative to the dipole.
:
: KD

HF Mobile - Grounding Antenna when stationary
 

VK2KCE wrote:

:
: Would it be preferable when camped / stationary to earth the vehile to a
: "ground" ground = what I am looking for is a better receive signal ?????
:
: Switching to a Dipole antenna suspended from the trees would be a Major
: step upward in performance.
:
: Mobile antennas have very low efficiency, grounding them will not improve
: that significantly relative to the dipole.
:
: KD

Efficiency doesn't even come into play in his case, being he is only
worried about receiving. As far as voltage to his radio, he already
has
more than enough with the mobile whip as is. As one mentioned, the
s/n ratio is what matters. And going to a larger vertical is likely not
to
help at all. Even switching to a dipole would not be an improvement
unless the signals are coming from higher angles, etc. IE: 75m NVIS..
There are cases where my mobile antenna outperforms my home dipoles.
But these will be cases where the distance, etc favors using a
vertical.
So anyway, the short of it is adding radials to the mobile will not
help receiving at all. And switching to a larger antenna is not likely
to
help either unless there is a reason such as a horizontal dipole
favoring
NVIS. All but the puniest mistuned receiving antennas have enough
voltage
to get an acceptable s/n ratio from any decent radio. It's like adding
a tuner,
etc to a random wire. Unless there is a specific reason for it, it's a
waste
of time in most all cases.
MK

HF Mobile - Grounding Antenna when stationary
 

VK2KCE wrote:
Korbin,
I have just done a heap of experimenting on 80m using a Terlin Outbacker
"Outreach" mobile whip.
I found that it made none or little difference when using 4 x 1/4 wavelength
radials.
I then used a 33 ft fibreglass extendable pole with a dipole attached,
certainly and naturally it outperformed the mobile whip.
I made up a full wave loop on 80m, slung it vertically between 2 large
trees, and found it out performed the dipole, mainly because of the noise
level was lower than either the mobile whip or the dipole.
On receive the full wave loop was the best, followed by the inverted vee and
lagging way behind was the mobile whip.
my 2 cents worth.
John

"Korbin Dallas" wrote in message
news:Uem7g.54594$Eh4.50096@trnddc01...
: On Sun, 07 May 2006 10:33:51 +0930, OZUser wrote:
:
: As an avid 4WD SUV owner I do a lot of outback travelling (Austrlian
: Deserts, Cape York, Kimberly Coast) and as such have a Barrett 950
HFradio
: &Barrett 910 Autotune antenna installed for comms.
:
: Would it be preferable when camped / stationary to earth the vehile to a
: "ground" ground = what I am looking for is a better receive signal ?????
:
: Switching to a Dipole antenna suspended from the trees would be a Major
: step upward in performance.
:
: Mobile antennas have very low efficiency, grounding them will not improve
: that significantly relative to the dipole.
:
: KD


Throw the terlin away and you will gain 6db by using a decent mobile
antenna, no joke. The thing is dummy load for dx.

You would not say that about vertical mobile antennas if you screwed a
1/4 wave whip on your vehicle using the same ground

Considering that people claim terlins to work when they tuner them to a
1:1 vswr is laughable really, with something like 40 ohms ground loss
resistance!


You could try a inverted L with a autotuner at the base if you wanted
better efficiency. A 6 meter fishing pole with 6 meters of wire
horizontal is a cracker antenna.

Worst mobile antennas are those base loaded auto tuning antennas from
codan and barret, they have a honest 12 db loss compared to a good
monoband 20 meter centre loaded whip.


When you antenna is short you better off using multiple very small
radials than a few long ones.

Just forget all the nonses and make a good centre fed doublet with open
wire feedline and use it on all bands. No Better or cheaper antenna around.

Yeah and forget those joke Dummy Load Antennas sold by Barret Codan and
Bushcomm. They a heap of crap.


Greg