What is the radiation pattern of a long wire antenna?
Long Wire / End Fed Wire Antenna Includes: With antennas of this length, the radiation directional pattern shows lobes that align more with the axis of the antenna as the length in wavelengths increases. Ultimately, the maximum radiation, and reception sensitivity aligns with the axis of the antenna.
What is a 9 to 1 balun used for?
These are sometimes known as a Magnetic Longwire Balun. Its really an impedance transformer (9:1) to feed a high impedance, end fed (unbalanced) random wire which is likely to be a few hundred ohms, and transform it into something closer to a 50Ω (unbalanced) coaxial input, hence UnUn.
What is an UNUN for antennas?
Definition & Usage The UNUN is a “UN balanced to UN balanced” matching transformer. It is used for non-resonant vertical antennas like our 43 foot or 33 foot models.
How long should a long wire antenna be for shortwave?
The length of the antenna needs to agree with the length of the longest radio waves that you want to receive. Shortwave broadcasters use frequencies that are from about 50 to about 400 feet long, and an effective antenna needs to be at least one-fourth of that length — and one-half is much better.
What is a 9 1 Unun transformer?
Magnetic Long Wire UnUn 9:1 These are usually called a Magnetic Longwire Balun. Its really an impedance transformer (9:1) to feed a high impedance long wire (~450 ohm), down to a 50 ohm unbalanced coaxial input. I have heard them called an UnUn which seems more appropriate.
What core for 9 1 Unun antenna?
My friend, Thom, W8TAM, built his 9:1 unun using an FT82-61 core, and it works great. G3TXQ has performed a number of experiments with different core types, and with the antenna he used, found Type 2 powdered iron cores to be preferable.
What is a 9 1 transformer on a long wire?
Magnetic Long Wire UnUn 9:1 These are usually called a Magnetic Longwire Balun. Its really an impedance transformer (9:1) to feed a high impedance long wire (~450 ohm), down to a 50 ohm unbalanced coaxial input.