The U6YRN is a UHFÂ antennaÂ for 432 Mhz, 70 cm band that offer a 12,1 DBi Gain. With this kind of antenna you can achieve good contatcs from a fixed station to another mobile or fixed , and you can use it to connect satellite stations , using a proper rotor.
But before you use it be sure to set the clamp connecting the driven element with gamma mach to put a minimum of SWR according to the UHF frequency you want to use .
The gamma match : It is manufactured with an aluminum rod 12.5 mm and in the middle a piece of RG8 Coax.
This will remove the liner and mesh lining leaving only protects the cable from the center to be introduced produce insulation between the aluminum tube and the cable that need to beÂ soldered to the connector previously set in the boom of the antenna, near the existing element. Respect the lengths and details of the table below toÂ properly adjust the SWR ( standing wave ratio ) . The spacing between the gamma and driven element is 2.5 cm.
|Boom||79.0cm x 2.5 x 3.8 cm.||Â|
|Reflector||35.2 cmÂ x 6 mm diam.||Â|
|Radiator||32.8 cmÂ x 6 mm diam||Â 14.1 cm.|
|Director 1||31.4 cm. x 6 mm diam.||Â 8.0Â cm.|
|Director 2||30.7 cmÂ x 6 mm diam.
|Director 3||29.7 cmÂ x 6 mm diam.||13.8Â cm.|
|DirectorÂ 4||28.3 cmÂ x 6 mm diam..||20.7Â cm.|
- Frequency: 430- 450 Mhz.
- SWR: 1.2 to 1
- Gain : 12.1 dBi
- FB Ratio: 26 dB
- Coupling: Gamma Match
- Gamma lenght: 5 cm
- Shunt distance: 3 cm
- Material: Natural aluminium
- Max Power: 600 W
original article by lu1dma