debtsilikon.blogg.se - Antenne 2 jt

Why not use more than one radiating element like a fan dipole ? Elevated the radials with 1 meter so that the angle with the radiator was 90 degrees solved the problem. The antenna itself was mounted on a sat mount, 1m AGL. After hours of examening, testing, unscrewing, other bolts I found the “problem”.

Initial tests were good, nice flat swr response, good copy on dx stations, …īut when finishing the antenna a few weeks later I noticed that I couldn’t find the resonance point back.

Removed the coil at the bottom, added 4 radials of a 1/4 wave at 20m and there it was. I was already playing with an old CB-antenna. This works, but the weight of the balun and the span of the whole thing decided me to go for something else. The test setup was a bit changed to a 4 band dipole with 1 inverted V for 10m, turned 90 degrees from the fan dipole. But also here not enough bandwidth on 10m. I figured out that I needed at least 15 cm between each element, the more the better. But the interaction between each element made it also difficult to tune. 5 Wires parallel for each band, fed by a balun at the common center. The next antenna built was a so called Fan Dipole antenna. That, the mechanical instability and difficulties in triming each band was enough to stop this project. But 15m also lacked the necessary bandwidth. Added in total 4 dipoles when I wanted to test it. Finally the first dipole was attached to the big cross. Bought speakerwire and started cutting and soldering.

He says = “Some people use them to make antennas…”. The funny thing was when I asked the sales person if the rods contain carbon fibers he mentioned that I’m not the first asking. I used cheap fishing rods, costing 4 to 5 euro each, from a known sports hardware shop. It is a small antenna and rather easy to build. The ZS6BKW Multiband HF Antenna Revisited.First I tried to build a Cobwebb antenna. Truth about the G5RV Antenna and two other improved alternatives to this basic design". : CS1 maint: archived copy as title ( link) What I learned from building my own G5RV / ZS6BKW Antenna "Archived copy". Reflections III: Transmission Lines & Antennas Practical Wire Antennas - Effective HF Designs for the Radio Amateur Varney, G5RV in The ARRL Antenna Compendium Vol.

^ a b G5RV multi-band antenna (Louis Varney, G5RV).

^ a b HF Antennas for all locations (L.

Two variations of the G5RV design, called ZS6BKW and W0BTU, can match several more amateur bands between 3.5–28 MHz without a transmatch. There are many variants of the G5RV antenna. All other frequencies require a transmatch. Ī transmatch (antenna tuner) is not required to use this antenna near its nominal design frequency of 14 MHz, and judicious length adjustments can sometimes include one other frequency band. Including a balun not only prevents RF interference but reduces receive noise and increases performance A length of at least 20 metres (66 ft) of 50 Ω cable is recommended for operation without a balun. A 1:1 current balun should be used between coax and ladder line. The ends of the symmetric feedline can be soldered directly onto a 50 Ω coax cable to the transceiver, however this is not good practice and should be avoided: It can result in high current flow on the outer surface of the coax braid, causing RF interference and degrading the polarization and gain of the antenna. As is in general the case for all electric antennas, the height of the G5RV above the ground should be at least half of the longest wavelength to be used. The dipole elements are 15.55 metres (51.0 ft) and the impedance-matching symmetric feedline (ladder-line or twin-lead) can be either 300 Ω (8.84 metres or 29.0 feet) or 450 Ω (10.36 metres or 34.0 feet). With a transmatch, it can operate on all HF amateur radio bands (3.5–30 MHz). The antenna can be erected as horizontal dipole, as sloper, or an inverted-V antenna. Louis Varney (G5RV) invented this antenna in 1946. The G5RV antenna is a dipole with a symmetric resonant feeder line, which serves as impedance matcher for a 50 Ω coax cable to the transceiver.