will an antenna work upside down?

For all your radio modifications, manuals, tips, reviews and guides

will an antenna work upside down?

Postby Warbo » Mon Oct 23, 2017 1:32 pm

so i built a j pole and its great, i then saw an article to build a "ladder cable j pole" on ham universe and
figured if i cut it to airband like the copper pipe one i should get a similar result...but ideally it needs
to hang out my upstairs window when in use and it will be upside down. does this matter? or is it a
total no no.
Warbo
 
Posts: 15
Joined: Tue Oct 10, 2017 9:32 pm

Re: will an antenna work upside down?

Postby G4RMT » Mon Oct 23, 2017 1:40 pm

The design put the main lobe between horizontal, or a smudge below, going upwards. So reversing it will limit the performance as it hangs vertically. As the house block the signal from 180 degrees of the circle, you could try angling it back a bit to raise the angle in the best direction?
G4RMT
 
Posts: 1426
Joined: Sat Feb 07, 2015 5:45 pm

Re: will an antenna work upside down?

Postby sinclairuser » Sat May 25, 2019 2:53 am

hi, you could always build the antenna upside down, so when its hung out of the window its orientation will be normal.
User avatar
sinclairuser
 
Posts: 13
Joined: Mon Mar 13, 2017 4:13 am
Location: castleford west yorks

Re: will an antenna work upside down?

Postby Chris P » Sat May 25, 2019 8:32 am

sinclairuser wrote:hi, you could always build the antenna upside down, so when its hung out of the window its orientation will be normal.





so long as the feeder coax is kept well away from the upper part of the antenna if it isn't the polar diagram will be deformed and the antenna will be detuned ( not that the close proximity to the building doesn't do that anyway :wink: ).

J poles and slim jims will only work at their best when in the clear with their feeder below the antenna
Regards Chris aka G8FFF nipper or tazmin88
Chris P
 
Posts: 473
Joined: Sun Nov 02, 2014 12:20 pm
Location: 6.5nM west of 06 threshold marham


Return to Radio & Scanner Mods, Manuals and Tips

Who is online

Users browsing this forum: No registered users and 1 guest