I want to transmit FM RF with high
gain antenna like Yagi, help me in
basic way plz:
1. I should have to feed rf in two ends
of dipole rediator only, isn't it?
First off, you have not told us what frequency you want the Yagi for ???
Most (not all) yagi's use a loop dipole feed
here's one for 433MHz that isnt and is pretty easy to construct it could be scaled to use on other frequencies....
2. I am confusing in Main Rod (which
connects reflector, dipole rediator and
directors) component. Does it should
have to be conductor? Are they all
small rods and main rod connected
electrically via Main Rod?
the boom can be metal or other material like wood or plastic
if it is metal as in the example pic above, then consideration needs to be given on how to mount the driven element
3. It is too much directional antenna
with high gain. May I know, in which
direction it can transmitt? And how to
stand this Yagi in the sky to transmit
horizontally?
the higher the gain the sharper the beamwidth (ie. the more directional it is)
it transmits in the direction you point it
you need to mount it on a pole, using U bolts anyone selling TV antennas will supply U bolts or a hardware store
4. Impedance matching Balun (75
ohm - 300 ohm) is necessary for Yagi
too, isn't it?
That depends on the impedance of the coax.... do you plan to use 75 Ohm or 50 Ohm coax ?
whether you need a 4 to 1 BALUN depends on the type of driven element you use
in the example above it is a 1 to 1 BALUN
for a folded dipole driven element in a Yagi, the impedance is usually around 200 Ohms
this makes a 4 to 1 BALUN and 50 Ohm coax ideal
cheers
Dave