Please Name My Blog » vhf

Simple L antenna (2 meter antenna)

mypapit — Mon, 21 Sep 2009 10:49:39 +0000

Here’s the simplest antenna that you can build to transmit with your HT or mobile rig when you have nothing else to rely to. The configuration gives you a 3.5dBi gain and it is simple to construct when you’re at outdoor.

I built this antenna, specially for hitting repeaters during lightning storm, as my usual high mounted antenna might attract lightning.

This antenna can be built using any conductive wire. Though, for my configuration, I use thick copper wires with the length A = 0.525m and B=0.4815m. The A-B angle is about 100-110 degree. It gives SWR 1.0 between 145.5MHz – 145.8MHz and SWR 1.3 at 148.0MHz, the edge of 2 meter amateur radio band.

Kota Setar Local Repeater Frequency (Gunung Keriang Kedah)

mypapit — Thu, 29 May 2008 17:48:10 +0000

Here’s the detail of Kota Setar Amateur Radio Repeater Information :

Frequency : 145.525 MHz
Shift : – 0.600 MHz
Tone : 103.5

Apart from the surrounding Kota Setar area, the repeater is triggerable from Perlis, Langkawi and Sungai Petani, the repeater was erected and maintained by Kota Setar Amateur Radio Club

All licensed ham are welcomed to use this repeater.

OWA 4 Element Yagi for 2 Meter – Great F/B ratio

mypapit — Sun, 27 Jan 2008 17:19:14 +0000

I would like to share with you a compact 4 Element Yagi-Uda antenna design for 2 meter amateur radio band. This antenna has great front-to-back ratio and is optimized for wide range of frequency, a bargain for its compact design (about 76 centimeter long).

Although this antenna has almost the same gain as any simple 3 element yagi antenna (7-8dBi), this design has a significantly improved Front-to-Back ratio which is great for blanking noises and foxhunting purposes

Here how the antenna would look like

Front-Back Ratio Gain

VSWR from 143.000 MHz to 148.000 MHz

Antenna dimensions
Element, Length, Space from Reflector (all in cm unit)

Reflector – 103.0, 0.00
Driver – 95.0, 26.0
Director 1 – 92.0, 39.0
Director 2 – 83.0, 76.0

Calculated Center of Gravity – 35.0 cm

This antenna has been modelled using YagiMAX 3.0 software by K4VX

Please leave comments if you have sucessfully built this antenna. I would like to hear your experiences.