Home |
Search |
Today's Posts |
|
#1
![]() |
|||
|
|||
![]()
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 ????? |
#2
![]() |
|||
|
|||
![]()
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 |
#3
![]() |
|||
|
|||
![]()
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. |
#4
![]() |
|||
|
|||
![]() "Dave" wrote in message news ![]() 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). |
#5
![]() |
|||
|
|||
![]()
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 |
#6
![]() |
|||
|
|||
![]()
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 |
#7
![]() |
|||
|
|||
![]() 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 |
#8
![]() |
|||
|
|||
![]()
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 |
#9
![]() |
|||
|
|||
![]()
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 |
#10
![]() |
|||
|
|||
![]()
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 |
Reply |
|
Thread Tools | Search this Thread |
Display Modes | |
|
|
![]() |
||||
Thread | Forum | |||
Why Antenna Tuners Aren't Necessarily Useful for Shortwave Listening - Question Shortwave Listening (SWL) Antenna Tuners - Do You Have An Opinion ? | Shortwave | |||
Why Tilt ? - The Terminated Tilted Folded Dipole (TTFD / T2FD) Antenna | Shortwave | |||
On Topic | Shortwave | |||
Questions -?- Considering a 'small' Shortwave Listener's (SWLs) Antenna | Shortwave | |||
Mobile Ant L match ? | Antenna |