Radiation Pattern

Related discussion about towers, masts, and transmissions lines

Radiation Pattern

Postby VK2CSW » Fri Nov 30, 2018 7:37 pm

Not quite a tower or mast but it is an antenna mounting question :)

I recently came across a FAMPARC Mult-tap whip I had taken of my last ute and that was languishing in the shed, so decided to put it to use.

In the back garden I have a 4800x2400mm raised garden bed that has a treated pine frame of the same dimensions supported, again by treated pine posts, about 1800mm above ground level. Stretched over the frame is a galvanised chicken wire "roof". The garden bed is oriented roughly north-south on the long axis.

In the centre of the southern end I have mounted the whip (the chicken wire roof is the ground plane). The idea of mounting the antenna at one end was to bias the radiation pattern in a northerly direction.

So far, so good. Using FT8 on 15 through 40 metres it far outstrips the HVU-8 and 20 metre dipole mounted above the roof line of the house. In fact, it is surprisingly better.

My question is; if I was to move the antenna to a corner of the frame, with all else being equal, how different would the radiation pattern be? For example, if I moved the antenna to the south west corner would the radiation pattern be altered to a significantly more noticeable north-east alignment? As opposed to the surmised more north-south alignment of the current set up.
______________________________________________________________
Colin
VK2CSW
Where are we going? And exactly why am I in a hand-basket?
VK2CSW
Forum Diehard
 
Posts: 370
Joined: Sat Jan 23, 2010 5:10 pm
Location: QF56NI - Mt Colah NSW

Re: Radiation Pattern

Postby VK2CSW » Sun Dec 09, 2018 4:09 pm

I guess 100 views and no replies means I need to get one of those modelling programs then.
______________________________________________________________
Colin
VK2CSW
Where are we going? And exactly why am I in a hand-basket?
VK2CSW
Forum Diehard
 
Posts: 370
Joined: Sat Jan 23, 2010 5:10 pm
Location: QF56NI - Mt Colah NSW

Re: Radiation Pattern

Postby VK4TI » Sun Dec 09, 2018 5:06 pm

[quote="VK2CSW"]I guess 100 views and no replies means I need to get one of those modelling programs then.""

Or try it ad determine the tilt from results
VK4TI
Forum Diehard
 
Posts: 712
Joined: Wed Dec 19, 2012 6:25 am


Return to Towers, Masts & Transmission Lines

Who is online

Users browsing this forum: No registered users and 2 guests