[Antennas] 40m mobile antenna e.r.p. compared

[Sam Morgan]

Hello folks,

I have spoke with my landlord and it seems I will get the ok for an
antenna of a size comparable to a mobile antenna 8' to 10', might sneak
it up to 12'?

The roof is flat and made of rolled shingle. 
The size of the roof is 29'x49'.
The roof height is 19' above ground.

Antenna base will be placed on a metal plate 2'x2' located in the center
of the roof, with four 1/4 wave radials extending from the plate.

For this case lets limit the frequency(s) to 40m only. I know the
bandwidth may be limited, but I'll address that aspect in another post.
My question is, which antenna would have the highest effective radiated
power. (least loss) I will probably be running 25w or less, so this
factor is a big concern to me.

In THIS post I'm looking for comparisons of commercially available
antennas.

(I'll be asking in a seperate post some questions related to
a homebrewed antenna(s)) 

Antennas I am reading about include the following:

http://www.hamstick.com/9106.htm (40m hamstick)

http://www.mfjenterprises.com/products.php?prodid=MFJ-1662 (screwdriver)

something created from parts from these folks:
http://www.dxengineering.com/Sections.asp?ID=47&DeptID=24#Top

----
If I win the lottery perhaps one of these:

http://www.texasbugcatcher.com/index.html

http://www.qth.com/n7lyy/

http://www.hiqantennas.com/HiQ2580.htm

to bad this one is 20' .. it's so..so..<not> cheap ;-\ 
http://www.hiqantennas.com/HiQ-tune-a-vert.htm

http://thescrewdriver.com/


TIA for your replys.
  

Sam Morgan
KA5OAI
mailto:ka5oai at qsl.net