A guide to receive far away FM stations

[raja_meghana]

Probably you could try coaxial cable used for TV antennas as an outdoor antenna before going for any signal boosters. The following is a link to one such design. It is very very simple to construct and very cost effective. You can use a small piece of wood to support and keep it straight horizontally. In fact I made one to receive fm transmission which is aired via 1 kw transmitter from a distance of 30 km. here is the link.

Make your FM Dipole antenna by dxzone.com

Link for simple fm loop you can try for better reception

Simple FM Loop

to order a mosfet-based fm signal booster circuit and components from elecronicsforu website, but you have to have some knowledge in electronics to assemble it.

Circuit lab, diagrams,Free circuits, Electronics periodical, e-mags: India

 

[jim]

Hi everybody,
After reading the previous posts, i thought to share something which might be unknown to some people. Receiving far away FM stations is called FM Dxing. I am from Ranchi(Jharkhand) and unfortunately here we dont have private FM stations except Vivid Bharti:wall: . But i do listen to FM stations of Kolkata(Calcutta).
I want to make it clear to everybody that high frequency signals travel in the line of sight and these high frequency signals can either be FM or AM.
So, saying that FM signals travel in the line of sight is partially correct.
Low frequency signals like MW and SW also travel in the line of sight but they also get reflected by the one of the layers of atmosphere. So we can listen to faraway stations in these bands.
High frequency signals do not get reflected rather they pierce the layers of atmosphere and are lost in space leaving only one option: line of sight transmission.
But there is a special layer in the atmosphere called ionosphere which helps in reflecting the high frequency signals. Although not always present, this layer is responsible for FM Dxing.
To receive distant signals you need:
1) A good FM receiver. (I have got my Sony home theatre which works very well)
2) An FM Booster(Not those TV boosters)😕
3) A home made antenna.
You can get a plenty of circuits diagrams in the internet for FM booster.
Print out the diagram and either make it yourself or give it to the technicians who repair TV and radio.
The antenna can be a simple one like a whip antenna if you want to listen to nearer stations or it can be a complicated one like Yagi antenna. I made a quadrangular antenna.
With the help of above things, i receive FM stations of Calcutta. In a straight line it is more than 350 Kms from Ranchi. The signals become clearer in the night and they become stereo from mono.
Thus my setup receives whatever signals it gets from line of sight and from ionosphere reflections.
Some other facts:-
Aircraft communications also use high frequencies (118-136Mhz) and they talk in line of sight BUT THEY ARE NOT FM, they are AM (amplitude modulated) signals like those of Medium wave and Short wave.
One interesting thing:- One day when i switched on my system i wasnt able to receive Kolkata FM stations rather i was receiving radio stations of Burma(Myanmar) . I took out the map and measured the distance of Burma. It was more than 1500 Kms. Isnt that interesting:yahoo:May be due to changes in the ionosphere i was able to receive them.
It might seem surprising to you that i am a Doctor but electronics and communication is my hobby. I hope you enjoyed reading my little article. Need any help?

Sir,
I really enjoyed ur article. I am a civil engineer with ur same interest. I am from kerala where FM stations are not available. Now many new private stations started which are 110km to 170km away. Ur article inspires me for FM Dxing. I have down loaded an FM booster circuit. Now I would like to know the details of an home made antenna (quadrangular). If u don't mind pls giv me the details to construct it.
with regds,
jijimon
email : jijipm@yahoo.co.in

 

[mcx]

Hai everybody, I am also a radio enthusiast living in kerala,(near kottayam in kerala) this place is not in the primary coverage of any fm transmitter so without doing anything it was difficult listen to fm here ,really :and so I was using external yagi antenna for the last 8 years . Really like to listen to and share anything related to FM radio particularly fm dxing.it was my hobby since childhod I would like to thank mundle 2002 and others for thier posts in the forum which i found so interesting. I would like to ask one thing : the impedance of yagi is 300 ohm right,so what cable would u guys recommend to connect a 300 ohm ribbon cable or 75 ohm coax ? Or adding directors to decrase the impedance to connect a coax? but will it become 75 ohm? .or these impedence mismatch really doesn't really matter? but whenever I use long cables the signals received at the antenna die out as thay come down which made me use an old tv VHF booster 300 ohm which is not optimised for fm amplification .I couldnt build an fm amp myself to satisfaction yet because i am not a professional in these things (,actually i'm a junior doctor trying for pg entrance )so still using the old one.these things are not available in the local shops here. Any how hail the fm revolution in kerala ! Expecting replies with regards mcx

 

[jishnu1980]

hello jim and mcx iam also from kerala intrested in radio i wish to make friendship with u guys iam also a professional if intrested contact me on mail jishnu_male@yahoo.co.in

 

[mcx]

Hai Jishnu, great to have u as friend. Its good that we have a common interest in radios. U see the problem was that I couldnt talk to my friends about these things or ask them any doubt here as they were least bothered about fm radio.everyone is in front of the satelite tv or dvd or seeiing streaming video/audios from the internet so i never had an outlet to speak or share my apparently rare hobby.Its good that i get an opurtunity here like to listen to radio at home as a background audio and in car.But unless we get a hazzle free reception in mobile phones or inexpensive radio sets here the general public will not have a likeness for it especially in my place. It seems with the coming of new private stations radio is back and generating lots of interest at least in the major cities in kerala.But I think people from other states are better listeners than malayalees.When in big metros I found that alsmost every young person in the bus, train in the park,....seems to be enjoying,listening to radio stations in their mobiles and also in taxis ,autorickshaws ,everywhere fm stations had a better reach than tv in the city because they where available on the move.they dont have to buy cds or download music off the internet as new songs where played in the radio with near cd quality. My problem with reception is that the power of signals are fluctuating.in day time big 92.7 and radio mirchi from trivandrum, i get crystal clear stereo reception which will die out comletely ,in 1 or 2 minutes it becomes clear again in another minute this continues all the day.In the night it is good.I'm desperately trying to increase the gain.any suggetions?

 

[neevarp]

Another ardent radio listener in here 🙂

 

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[icar]

Thank you, learn many things in one go

🙄@seshu It was very interesting thread to me & to convey Thanks to all guys does not deviate Main Topic

 

[seshu]

^ [off topic]
perhaps meant that he learnt / learned many things from this thread !

 

[raja_meghana]

any active dxers with antenna designs and preamplifier circuit ideas to receive distant fm stations?

 

[essbebe]

Amateur Radio Antenna Projects
Just try the lengths for 6 M by reduced by 55%
Try ONLY the dipole first
More antennas
Beam Lengths

Orient the Antenna towards transmitter direction for best signals.
Height should be at least 30 feet from ground level ( to avoid building etc obstructions)
Calculating exact measurements. for center freq 98 MHz of 88 -108 FM broadcast band.
more "Gyan" depending on feedback.

Para two : Old TV antenna Boosters can be also tried.

 

[mcx]

Amateur Radio Antenna Projects
Just try the lengths for 6 M by reduced by 55%
Try ONLY the dipole first
More antennas
Beam Lengths

Orient the Antenna towards transmitter direction for best signals.
Height should be at least 30 feet from ground level ( to avoid building etc obstructions)
more \"Gyan\" depending on feedback.
Para two : Old TV antenna Boosters can be also tried.

Hey I notice that Car Fm Sets even with poorly optimised arial are picking up weak stations sometimes 400 km or more distant in a good location, especially the Sony, pioneeer blaupunkt sets.I suppose they are having high gain amplifier. Does anybody have ampifier circuits designed specially for fm band rather than vhf tv booster ?

 

[jobinjv]

if anyone has tried to make the fm dxing amplifier can u help me clearing a doubt. how to do the RFC in the circuit where the coil is wound over the resistor. does nayone have any picture to post

 

[jim]

Hai,assembled the FM booster cicuit and yagi antenna. but not getting any distant FM stations. NOt known whether the booster works? How to check it? Any could help me ?jim

 

[essbebe]

@jimGood show.Try the Yagi Antenna for the local FM station at ground level and rotate it.The signal should increase as you orient the Yagi towards the Transmitter direction.Say " Due South' 180 degrees. Now add the booster and look for Fm stations in same south direction.Say you are in Cochin, Tiruvananthapuram. Kollam( if it has a FM) could be received.You will find during Summer reception is possible. early mornings and evenings. I am hearing Sri Lanka Amateur "HAM" stations in the night , for short duration.Also in Chennai from Yercaud( Salem) morning and night ( power is barely 10 or 20 Watts). Remember, long back SriLanka Television was picked up even in Chennai. Your "Booster" is equivalent to an "Active Antenna" with built in vhf band amplifier. Since it is only for reception of VHF signals I am ignoring some loss/mismatch in the cable used.PS: Any DD TV station in your area ? What is the VHF freq ?

 

[jobinjv]

Hai,
assembled the FM booster cicuit and yagi antenna. but not getting any distant FM stations. NOt known whether the booster works? How to check it? Any could help me ?
jim

did u assemble the mosfet based circuit or a normal FM booster.