Tuesday 25 February 2014

Workshop on 2 Meter Yagi Directional Antenna

A 2 meter 7 element Yagi antenna workshop was conducted by the Radio Amateur Society of Ananthapuri (RASA) at Kerala State Science and Technology Museum & Priyadarsini Planetarium on 19/01/2014. The antenna workshop was inaugurated at 9.00 a.m. by Shri. Krishna Kumar, Scientific Officer, KSSTM in the midst of all distinguished hams of Trivandrum. The important hams who were present at the occasion were Zakir Hussain VU3OOH, Binoy VU3BRD, Dr. P. Raveendranath VU2RVJ, Allen VU3AUZ, Alex VU2PAG, Anil VU2KHC etc. A directional VHF antenna has been a long time demand for all those hams who operate on VHF from Trivandrum. This is due to the fact that the directional antennas have a greater chance of accessing many distant VHF repeaters in the State of Kerala as well as the the State of Tamilnadu or wherever as the need arises for long distance simplex contacts.


Photo credit: www.qsl.net

Directional antennas are used especially when greater distances are needed to be covered in a particular direction. These are unidirectional antennas unlike omidirectional antennas which transmits signals in all directions perpendicular. Directional antennas have a gain that is quite considerably higher than the omnidirectional antennas used for amateur radio operations. The radiation pattern for the antenna shows the signal transmission in one direction that helps to establish contact between two distant stations through a long path possible. The signal is focussed in a single direction that makes the available signal in the direction of the transmission with improvement of the S/N ratio.


The Yagi antenna consists of an antenna boom, which holds the other antenna elements together, a radiating element, a tuning stub, reflector, and directors. This Yagi antenna consists of 7 elements in total giving approximately 11 db of gain with a front-to-back ratio 20-25 db. A gamma match is implemented using a piece of aluminum tubing and a piece of coaxial.

Photo credit: http://www.hamradio.in/



Photo credit: www.kj4pwp.com

The workshop was very informative and offered a very good opportunity to get first hand knowledge on the construction of VHF Yagi antennas. We also had an occasion to have an eyeball with the compatriot hams and prospective hams and SWLs. Everybody enjoyed these sessions and wished hopefully to meet again many more times for more of these workshops and practical events.

Persons who participated in the workshop:

Dr. Zakheer Hussain           VU3OOH
Old man Binoy                   VU3BRD
Dr. P. Raveendranath          VU2RVJ
Old man Saji                      VU3SQG
Old man Allen                    VU3AUZ
Old man Anil                      VU2JQX
Old man Rajesh                  VU2RLW
Dr. Lesley Paul                   VU2LVJ
Old man Midhun                 VU3ONM
Old man Alexander             VU2PAG
Old man Anil                      VU2KHC
Dr. Sajeev T.T.                   VU3TTR
Old man Sumesh                VU3CHK
Old man Jaidev                  VU3RUD
Old man Abed                   VU3AUE
Old man S.R Nair              VU3SQR
Krishna Kumar                  SWL
Suwil Kumar                      SWL
Vinu Mohan                       SWL
Joel                                    SWL   





























 













Meeeeeee!!!