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2Meter Slim Jim Antenna
This 2 Meter 300 Ohm Slim Jim antenna is constructed from regular 300 ohm twinlead
post 29 Jan 2024
Antenna for UHF VHF Links →
Stacking with Coax Cables as Transformation Lines
The stacking cables are made of odd multiples of 1/4-coax-cables 3/4-, 5/4- or 7/4
The HB9CV 144 Antennas
The HB9CV is a well known two element antenna of a directional beam type with a forward gain of 4 to 5 dBd
The normal-mode helix antenna
A helix will work in the normal mode when the diameter and pitch of the helix is less than 0.1 Lambda When working in this mode the radiation is from the side of the helix, and when the diameter is considerably less than 0.1? the resultant 'spring' has a radiation pattern similar to a short vertical monopole or whip
Three Element Collinear J Pole
Working from the short end of the 5 sections of the J and looping counter clockwise through the top PVC Section, here are the measurements I used
155
The stacking cables are made of odd multiples of 1/4-coax-cables 3/4-, 5/4- or 7/4
The HB9CV is a well known two element antenna of a directional beam type with a forward gain of 4 to 5 dBd
A helix will work in the normal mode when the diameter and pitch of the helix is less than 0.1 Lambda When working in this mode the radiation is from the side of the helix, and when the diameter is considerably less than 0.1? the resultant 'spring' has a radiation pattern similar to a short vertical monopole or whip
Working from the short end of the 5 sections of the J and looping counter clockwise through the top PVC Section, here are the measurements I used
Take off angle of horizontal antenna For horizontal polarization, the electric field will move sideways on a horizontal plane, while for vertical polarization it will oscillate up and down on a vertical plane
Rx antennas 4Square Rx Vertical Array My frequency design of 1.825 MHz a 90 degrees line would be 33,70 metersinstead of the previously calculated 33,27 m
Calculo da Antena Bazooka A double bazooka antenna is a combination that has a complete coaxial wave multiplied by its velocity factor and a total end-to-end length of 1/4 wave for each side affected by another driver shortening facto