"dxAce" wrote in message
...


David wrote:

Make Folded Dipoles and use a CATV balun backwards at the feedpoint.
Then you can use plain old RG-6 and F-Splitters. Not only is this
incredibly cheap, the entire antenna system is at DC ground*.
Caution, do not use Baluns with little capacitor inside.

*Use an F Grounding Block where the coax enters the house. And a
drip loop.

http://members.shaw.ca/weskyscan/ima...ldedDipole.gif

I'd be a bit sceptical of that 300-75 ohm TV type balun. But then again
I'm
sceptical of anything that's 75 ohms.

dxAce
Michigan
USA

Several years back I had a contract to characterize a variety of CATV
splitters for marine use. Port to port isolation was abysmal below 5MHz,
insertion loss and return loss well below rated spec - Their need extended
down to MW, so I could not recommend any of the ones we tested.
If you have a field strength meter, here's a simple test to evaluate a
baluns actual balance.
Connect the 75 Ohm end the the FSM input. Connect a short wire to one lead
of the 300 Ohm end; tune in a loud SW station near the freq of interest and
note its level in dB. Being careful not to move the wire, short both sides
of the 300 Ohm and note the new level. At V/U the change is typically 30dB
indicating acceptable balance and pretty much guaranteeing the outer shield
of the coax will not be a significant part of your antenna. At HF, its
anybody's guess.

I seem to recall that the wider bandwidth of the folded dipole configuration
is attributable to the effective larger diameter conductor- probably easily
offset by using a larger wire diameter in a classic wire dipole.

Dale W4OP