MARS

Amateur Radio Society

Technical Presentation - Antenna Mystries

2024 Nov 23 OM Rajesh VU2OW

The last Members Eyeball QSO of the year 2024 of the MARS Amateur Radio Society was held on 23rd November 2024, at 'Hall no.1960 of the Dept. of Chemistry, College of Engineering, Guindy, Anna University., Chennai, at 6.00 pm IST (1800 hrs).

After the initial chit chat, the formal meeting began at 6:45 pm with the President OM P.Thyagarajan, VU2PTR welcoming the gathering. He went on to inform about the successful filing of returns with the Registrar of Societies (ROS). He also informed us that so far 89 members had been officially enrolled in the society of which 18 were new members. He also gave a brief about the details of the proposed 'Field Day' event and the workshop planned for the members in the forthcoming days.

Then the Secretary VU2DPN, OM Deepan, introduced the speaker of the day, VU2OW, OM Rajesh and invited him to deliver his tech talk. Mr Rajesh covered various types of antennae used for High frequency and very high frequency operation. He explained in detail the construction of simple dipole with ladder line and its performance. He covered other types of antennae like vertical, J pole, G5RV, End fed, Delta loop and ground plane. The advantages of each type were brought out in detail. He explained the relation between the power transmitted and ‘S’ point at the receiver’s end. The use of antenna and direction of propagation was also explained by him. He showed pictorial lobe formation of various type and its effective radiation. The take away of the presentation by Rajesh for the members was the emphasis on putting up a dipole antenna with random length with focus on operating on all bands of HF using antenna tuners and low loss transmission lines, rather than struggling to put up resonant antennas with band restrictions. On higher bands, resonant antennas with special dimensions / loading coils for higher isotropic gains can be used.

Subsequently, VU2DA, OM Manohar presented a memento to Mr. Rajesh. The meeting came to an end with a vote of thanks proposed by the secretary..