What is a 4 1 UNUN used for?
What is a 4 1 UNUN used for?
In order to bring the impedance within the range of a good external or built-in asymmetric antenna tuner, a 4/1 UNUN (Unbalanced to Unbalanced) impedance transformer is used, as a pre-match unit. The UNUN assures reasonable low VSWR values on the coaxial feedline, avoiding excessive losses.
How long does it take to counterpoise?
20-30 feet
Length of counterpoise should be a minimum of 20-30 feet but longer is better. If possible run the counterpoise above ground away from or perpendicular to the antenna wire and do not ground the counterpoise at the unun. You can also use the unun with no counterpoise or ground if your feedline is at least 25+ feet long.
Does end fed antenna need counterpoise?
No, it is not needed, but it can improve the antenna system. An EFHW is simply a half-wave length of wire and a matching device, and that’s it. Counterpoises are commonly added to shunt common mode reflections when operating outside of the wire’s resonant frequency to avoid RFI issues (“RF in the shack”).
Can I use a tuner with more than 100 watts?
Do not use this tuner or any unshielded tuner with more than 100 watts. Do not touch any of the conductors while transmitting. To use this tuner, connect to your radio and tune to the desired frequency.
What is an antenna tuner?
An antenna tuner is an impedance matching network that connects the transmitter and the antenna. Antenna tuner plays a very important role in short-wave radio communications. Due to different antennas and operating frequencies, the impedance presented by the antennas can vary greatly.
How do you use a capacitor as a radio tuner?
To use this tuner, connect to your radio and tune to the desired frequency. Set the capacitor to the middle of its range and select the tap point on the coil that gives the greatest received signal when connected with the clip lead. Then transmit at low power while tuning the capacitor for a dip in SWR.
Do I need a tuner with a BNC antenna?
A BNC will handle this fine. IF YOU USE A TUNER, THE ONLY COAX YOU SHOULD USE IS BETWEEN IT AND THE RADIO OR AMPLIFIER. A tuner is only suitable to two types of antenna viz. 1) a single long wire using ground as the counterpoise and 2) a balanced antenna of some kind.
