Folded Dipole Antenna

I have a 300w transmitter, and four folded dipoles with an erp of around 1200w,How far should i space the dipoles on the mast between each other, And what lenght should the boom arms be,, I have a 16metre mast...! Please help...
Thanks.....

in order to get that much gain from just 4 dipoles, each bay is spaced 1 lamda vertically. lamda is 300/freq in MHz. So for FM at 100 MHz, the spacing is 3 meters. However the bigger problem will be to get the power splitters to equalize the power exactly in phase at each bay. Any phase delay will cause the main lobe to shift from the horizontal and/or generate power cancellation nulls.

2008-03-13 15:05:55 by rex2e

This is my 27Mhz CB antenna, its a double folded dipole made of Belden 9913 coax cable fed by rg58cu coax, I made this around 15 Years ago amp ...

I bought a 75-300 ohms transformer (coaxial to twin-lead) at RadioShack for my folded dipole antenna. Is this thing also a balun, or is it just a converter and I need to add a balun before connecting my antenna to this converter?

I am talking about this: http://www.summitsource.com/images/produ cts/CO105T.jpg

>Is a 300 to 75 ohms converter also a balun?

Yes.

These come in two different configurations. Usually you would use this type:
http://www.summitsource.com/philips-75-3 00-ohm-pushon-quick-connect-matching-tra nsformer-balun-75300-ohm-offair-tv-anten na-balum-coax-cable-female-signal-adapte r-part-pvba10-p-4896.html

You can use the one you bought but you will need to find a way to attach it as the connectors are reversed. For example nuts & screws or soldering the spad ends. You would also need an additional coax cable to connect the balun to the converter's antenna input.

The one you bought would typically be used to connect a coax antenna lead to a real old TV that used 300 ohm screw terminals for the antenna input.

2009-05-10 08:42:20 by core2extreme

Price: $119.99