My DIY Yagi Antenna for FM Band

DIY Yagi Antenna

Since I live in Kalyan receiving clean & clear FM signals was always been a major problem to me. Therefore in spite of having many receivers I always suffered from disturbance in FM signals. Kalyan is situated around 50 Kms away from Mumbai. As per Govt. of India policy the private FM operators need to install their transmitters on Govt. towers. In Mumbai all the private FM operators have their transmitters on Mumbai Doordarshan's TV tower at Worli. I tried with many tricks from Rabbit's Ear Antenna to a long wire stretched up to the terrace to receive the clear signals. However for many years i did not get clear FM Stereo Signals. Since Kalyan is surrounded by Parseek Hills around Thane, it is very difficult to get a direct path for the radio waves.

This was until I stumbled upon a content on the Internet regarding the antenna design.The pictures are displayed below.

The dimensions are calculated taking in to consideration center frequency of 100 Mhz.

1 - director 1 120 / frequency 

A - interval betwen 1 at 260 / frequency

2 - director 2 125 / frequency 

B - interval betwen  2 at 345 / frequency

3 - director 3 130 / frequency 

C - interval betwen  3 at 430 / frequency

4 - director 4 138 / frequency 

D - interval betwen  4 at 530 / frequency

5 - Dipôle 143 / frequency 

E - interval betwen  5 at 648 / frequency

6 - reflector 150 / frequency 

The details are available on the following link.

http://radio.meteor.free.fr/us/antenna.html

http://radio.meteor.free.fr/us/yagi_fm.html

For at least an year I was planning to build one but could not get time for the build. In last week I decided to build it according to the plans depicted above.

Materials Required.

1) 8 mm Aluminium Tubing.

2) Wooden strip 1"x 1.5" x 7' size.

3) Small PVC pipe & a Tee Joint.

4) GI Pipe 1" x 6' Long

5) Twin Lead Wire.

Cost Involved

1) Aluminium Tubing - Rs.480/-

2) Wooden Mast - Rs.30/-

3) GI Pipe  - Rs.300/-

4) PVC fitting - Rs.30/-

5) Twin Lead Wire - Rs.50/-

6) Most Important  - Angry stares from Wifey.

Total - Rs.890/-

It was very difficult to find aluminium tubing locally. Finally I got it in Metal Market at Kalbadevi. The tubes I got were of 12' long & it was very difficult to transport these to Kalyan in tact. Ultimately I cut all the tubes to size in my Parent's home in Lalbaug. 

The most difficult part was to make a dipole as it involved bending of the tube. I tried every trick but I did not suceed in making exactly parallel U bends in one plane. Ultimately I settled for cut GI cloth hanger & got inserted in to the tube. So now my antenna is made up of composite material. The construction though looks simple, it is very difficult to fabricate it without proper tools. The photos of my antenna are attached below. 

Since my receiver accepts 300 Ohm unbalanced antenna, I did not go for a balun and a coaxial wire. I used twin lead wire for the connection.

Its been 12 Hours now & I am getting clean & clear FM stereo signals from 8 out of 9 FM Radio Stations. The only remaining station too i am getting in Mono.

Hope this post encourages other people to build one.

I am welcome to your queries. So dont hesitate.