Electronics and Technical resources from vu3dxr
Amateur Radio – End fed Halfwave antenna – Web resources and links An end-fed half-wave (EFHW) antenna is a type of radio antenna that is a half-wavelength long and has its feed point at one end. This makes it a very simple and compact antenna, and it is often used for portable or temporary applications. …
A short linear loaded ham radio band HF antenna is a type of antenna that uses linear loading to reduce its physical length. Linear loading is a technique that involves adding parallel conductors to the antenna elements. This increases the antenna’s effective length, allowing it to operate at a shorter physical length. Short linear loaded …
This 80M Trapped dipole antenna is the work of Nadisha 4S7NR, modified by YC0HLE which results are matched at a frequency of 3,845 MHz. This design will be resonant at a frequency of around 3,250MHz to 3,850MHz. Coil inductance = 67.83 µH, made of email wire diameter = 1 mm, diameter of the cocker = …
Modified simple horizontal V antenna This antenna is little modified version of antenna designed by Adam 9A4QV for noaa/METEOR Weather sat reception. Adams antenna is based on a very simple linearly polarized dipole, which makes construction almost trivial. I tried his antenna and found that practical difficulties in finding choc block terminals. Chock block terminals are not strong enough …
Multiband Half wave end fed antenna The end fed half wave antenna is an attractive option for many radio amateurs as it is able to provide multiband operation without the use of traps or stubs whilst occupying a minimum amount of space. A broad-band matching network is typically used to transform the high impedance of …
Rothammels Antenna Book For many years, radio amateurs have been using this reference book, which has acquired a firm place in amateur-radio literature as an “antenna cookbook.” Dating back to the fifties, it has developed into a comprehensive reference book for practical use, which has been published in numerous German-language editions. In the interest of …
1:49 UNUN using two stacked FT240-43 cores for end fed halfwave antenna In order to match the end fed half wave antenna to the coaxial feeder, it is necessary to have a matching network or transmission line transformer. The coaxial feeder is likely to be 50Ω and the antenna impedance is possibly around 4000 or …
VK4FUQ’s optimised sloper antenna for 3.5MHz. Radiator and counterpoise radial are both one-quarter-wave in length (length in metres = 71.37/(frequency in MHz) or in feet 234/MHz). The radial should be at least 5ft (preferably about 8ft) above ground and immediately underneath the radiator. Good quality insulators are need at the top of the preferably non-conductive …
Half Rhombic antenna with counterpoise was published in RSGB Radio Communication magazine December 1996 page 62. Refer for more info about broadband terminated end fed antenna here.
Terminated End Fed Vee Antenna (TEFV) Author : D.Prabakaran VU3DXR Figure1 – Terminated End Fed Vee antenna It is a travelling wave antenna, which has a constant current distribution along its length. Antennas usually used by radio amateurs are resonant standing wave types like dipoles. It is built to a specific tuned length so that …