I built an interesting indoor antenna recently.
The antenna is asymmetrical but I use a wide range T-match manual tuner with an integral 1:1 current balun directly at the broken open gap directly feeding the two vertical halves
The antenna is physically vertical about 16ft broken open and fed off center where 10ft downwards toward the earth and 6ft upwards toward the ceiling.
The topmost vertical part consists of two wiresthat are shorted together at the top connecting that have been expanded to form a square 15ft X15ft shape capacity hat then they are twisted together when returning downwards towards the tuner where they terminate and connect I have crimped and soldered ring terminals attaching both ends to the remaining balanced tuner terminal.
There is NO feedline.
The bottom vertical wire ends about 5ft above earth.
The feedpoint height is about 15ft above Earth surface.
The tip of the pair shorted and then connects to the hat is about 21ft. up.
The antenna looks like an off center fed vertical doublet with a twisted pair forming the top vertical that taps a 15ft X 15ft top hat.
The antenna is working from a frequency range of 20m-10m.
A Asymmetrical vertical doublet with no feedline and a capacity hat on the ceiling
Thanks Bob, sounds like an interesting arrangement!
So is this antenna in one room?
Actually you do have a feedline (from what I can gather reading the above) - it goes from the rig to the T match manual tuner. Of course it doesn't have to be very long ... matching (or tuning) the antenna at the feedpoint is one way to reduce feedline loss due to mismatch. One still needs to go from the matching device to the transmitter.
What's the resonant frequency of this antenna? Work any interesting stations?
73, Rich, K3VAT