Call Search
     

New to Ham Radio?
My Profile

Community
Articles
Forums
News
Reviews
Friends Remembered
Strays
Survey Question

Operating
Contesting
DX Cluster Spots
Propagation

Resources
Calendar
Classifieds
Ham Exams
Ham Links
List Archives
News Articles
Product Reviews
QSL Managers

Site Info
eHam Help (FAQ)
Support the site
The eHam Team
Advertising Info
Vision Statement
About eHam.net

   Home   Help Search  
Pages: Prev 1 [2]   Go Down
  Print  
Author Topic: 43' Vertical Radials - More shorter vs. Less longer  (Read 4525 times)
W5DXP
Member

Posts: 3551


WWW

Ignore
« Reply #15 on: September 20, 2012, 12:10:20 PM »

My G5RV is only about 10' up in the air, so I'm expecting the vertical, with better feedline  and proper radials, to outperform the G5RV.

Here's what EZNEC sez about 10m operation:

G5RV at 10': 7 dBi gain at 34 deg TOA (take-off-angle).

G5RV at 10': 3.2 dBi at 15 deg.

43' vertical: 6 dBi gain at 56 deg TOA. 56 deg is fairly useless on 10m.

43' vertical: 0.5 dBi gain at 34 deg. Same as G5RV TOA.

43' vertical: -6.7 dBi gain at 15 deg.

In the G5RV's favored direction, it is 1-2 S-units better than the vertical at the low DX elevation angles. Hope you are not expecting a lot of DX out of a 43' monopole on 10m. However, it should beat the 10' G5RV on some of the lower bands.
Logged

73, Cecil, www.w5dxp.com
The purpose of an antenna tuner is to increase the current through the radiation resistance at the antenna to the maximum available magnitude resulting in a radiated power of I2(RRAD) from the antenna.
W8JI
Member

Posts: 9304


WWW

Ignore
« Reply #16 on: September 20, 2012, 02:32:27 PM »

Cecil,

He can always use the 43ft vertical as a mast to hold up his old G5RV.

:-)


Logged
N4NYY
Member

Posts: 4745




Ignore
« Reply #17 on: September 20, 2012, 04:49:04 PM »

Cecil,

He can always use the 43ft vertical as a mast to hold up his old G5RV.

:-)




That is so wrong! LOL

BTW, that mast that holds up my Imax for 10-15 is 42'. I stuck an I-bolt up there and ran my 20-40-80 trap dipole we discussed. I really wanted to add 160, but did not have the space. I was looking into loading coils for 160, but not sure how efficient and lossy they are. So I just left it at that.
Logged
K0OD
Member

Posts: 2539




Ignore
« Reply #18 on: September 20, 2012, 05:25:32 PM »

Quote
In the G5RV's favored direction, it is 1-2 S-units better than the vertical at the low DX elevation angles. Hope you are not expecting a lot of DX out of a 43' monopole on 10m. However, it should beat the 10' G5RV on some of the lower bands

I've worked plenty of DX on 10 and 15 meters with my 43 footer. Had a 10 meter inverted V up about 40' for awhile to compare it with, and the vertical was actually quieter on receive often (have no idea why). The V was an s-unit or two better broadside into Europe on many, many checks. I've also made a bunch of long haul Qs on six meters with my 43 footer.

I'd expect a 10' high G5RV to be about worthless for any purpose on any band.

43' verticals are just so-so antennas but I did use one to work exactly 100 different countries in the CQWW CW (low power) three years ago. 
Logged
KC4MOP
Member

Posts: 731




Ignore
« Reply #19 on: September 21, 2012, 03:28:17 AM »


My G5RV is only about 10' up in the air (I know it should be higher), so I'm expecting the vertical, with better feedline (LMR-400 as opposed to RG-8X on the G5RV) and proper radials, to outperform the G5RV.


Do not bet the farm on it. The 43 foot vertical will be at a disadvantage on 20m and above with a higher angle of radiation. 
SO TRUE!
Your 10 foot off-the-ground would surprise you when compared to a vertical. A dipole starts to become a great antenna 1/2 wavelength above the ground. My latest thoughts in re-purposing my antennas is: The 65 foot high full length dipole fed by OWL I use for 160-40M. I have a tribander up 65 feet for 20M- 10M.
Do not be discouraged. Your antenna is ok for 'local' work on the lower bands out couple hundred miles. It is making strictly high angle radiation on 80 and 40M. We call it 'a cloud warmer'.
And just a little tweek to W3TO's info. The 43 footer is close to being a 5/8 wave antenna on 20M. That makes it a possible hot DX antenna.
I know that this gets into a lot of static which is the better take off angle, but that's what a 43 footer becomes on 20M.
Only certain bands benefit from the 43 foot vertical. 20M, 30M, 40M.

Fred
Logged
WT3O
Member

Posts: 16




Ignore
« Reply #20 on: September 24, 2012, 10:40:48 AM »

Thank you all for your help!

Hopefully in the next few weeks I'll be adding more radials. My goal is 36 total: 16 that are 15', 8 that are 70' and 8 that are 35'. I'll let you all know how it works out!

73 de WT3O
Logged
KB4QAA
Member

Posts: 2324




Ignore
« Reply #21 on: September 24, 2012, 11:39:48 AM »

Thank you all for your help!

Hopefully in the next few weeks I'll be adding more radials. My goal is 36 total: 16 that are 15', 8 that are 70' and 8 that are 35'. I'll let you all know how it works out!

73 de WT3O
Now here is a case where the rule of thumb can help us.

Nearly all of the lines of flux are within 1/2 wavelength, but are densest within 1/4 wavelength.

You will get much more signal improvement by taking those 70' lengths, cut them in half and install 16 35' sections rather than 8 70' sections.   Again, the N6LF studies make this quite clear.   73, bill
Logged
Pages: Prev 1 [2]   Go Up
  Print  
 
Jump to:  

Powered by MySQL Powered by PHP Powered by SMF 1.1.11 | SMF © 2006-2009, Simple Machines LLC Valid XHTML 1.0! Valid CSS!