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: [1]   Go Down
  Print  
Author Topic: Vertical vs Dipole on fence  (Read 919 times)
KJ6TSX
Member

Posts: 116




Ignore
« on: April 08, 2012, 09:25:57 AM »

I have a dipole antenna less the poles ( wire stapled to the top of my fence approximately 7 feet off the ground) center fed with a 1:1 bauln, would I be better off to install a vertical multi-band antenna on the peak of my roof? My roof is approximately 20 feet high and I bet I could put a 30 foot antenna on top of that, currently I have a 10 meter antenna that is approximately 20 above the roof and the neighbors have not complained... Yet

Any insight would be greatly appreciated
Thanks
George
Logged
KB4QAA
Member

Posts: 2265




Ignore
« Reply #1 on: April 08, 2012, 11:44:47 AM »

You haven't given us complete info on anything that is comparable.

unknown dipole at 7ft

10m antenna on roof @20ft, vertical?

proposed multiband antenna on roof, vertical?


*What bands do you want to operate?

*Any additional height you can get on your current dipole will improve it.
Logged
W8JX
Member

Posts: 5447




Ignore
« Reply #2 on: April 08, 2012, 11:54:33 AM »

I have a dipole antenna less the poles ( wire stapled to the top of my fence approximately 7 feet off the ground) center fed with a 1:1 bauln, would I be better off to install a vertical multi-band antenna on the peak of my roof? My roof is approximately 20 feet high and I bet I could put a 30 foot antenna on top of that, currently I have a 10 meter antenna that is approximately 20 above the roof and the neighbors have not complained... Yet

Any insight would be greatly appreciated
Thanks
George

Generally a dipole will not offer any gain or directivity unless it is close to at least 1/2 wave above ground.  In the case of your 80 m dipole stapled to a fence, I think a decent ground mounted vertical would out perform it especially on long hauls. When a vertical is ground mounted, radials do not need to be resonant  even when antenna is. When it is elevated they need to be resonant.
Logged

--------------------------------------
Entered using a  WiFi Win 8.1 RT tablet or a Android tablet using 4G/LTE or WiFi.
KJ6TSX
Member

Posts: 116




Ignore
« Reply #3 on: April 08, 2012, 07:28:30 PM »

Quote
You haven't given us complete info on anything that is comparable.

unknown dipole at 7ft

10m antenna on roof @20ft, vertical?

proposed multiband antenna on roof, vertical?


*What bands do you want to operate?

*Any additional height you can get on your current dipole will improve it.

Your Right I didn't tell the whole story, most of my time is spent on 80 & 40 meters, I don't get home in till after dark so the higher frequencies are pretty dead.
 I am considering a Butternut HF-2v (vertical) or something similar and would replace the existing antron-99 with it. Currently I have a "Cobra Ultralite Kid" (Alternative Dipole) antenna on the roof which works better than the fence antenna on 40 meters and is useless on 80 meters. The house is only 40 feet long.

My fence antenna is a center fed dipole approximately 7 feet off the ground (stapled to the fence) each leg is approximately 60 feet and is in a horseshoe shape. the antenna is resonate at 3.900 Mhz the reason I cannot go higher is the Telephone and Cable wires run directly above the fence approximately 6 feet.
Thanks for the help
George
Logged
WX7G
Member

Posts: 5918




Ignore
« Reply #4 on: April 08, 2012, 07:36:04 PM »

The issue with a roof installation is the length of the radials. I think you will obtain the performance you want with the Butternut HF-2V ground mounted. A couple dozen radials, even if they are just 12' long, will provide good performance. 
Logged
WB6BYU
Member

Posts: 13020




Ignore
« Reply #5 on: April 08, 2012, 08:56:54 PM »

How far do you want to talk on 80m and 40m?  The dipole may be better than a vertical
for local contacts, while a vertical likely is better for DX.  (Adding a 40m element to the
fence would improve performance on that band, otherwise you can have high losses
in the coax feed.)

A vertical mounted on the roof would require radials tuned for each band - about 60' long
for 80m.  You'll have to run them to the corners of the roof, then bend them around
under the eaves or wherever to make them fit.
Logged
Pages: [1]   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!