Fm Receiver + Antenna for village

[music4mhell]

About 20 years back I had done exactly the same thing successfully in my village, where the nearest FM station (Cochin) was about 100 km away. At that time I used a home-made uni-directional Quad antenna which was tuned to the FM station frequency.

Making the Quad antenna: buy a long aluminium pipe of the type used in YAGI-Uda antennas, and cut it to a length equal to half of the FM station wavelength (perhaps it is quarter wavelength - I forgot - Please google to confirm). Bend this pipe into a square shape. Flatten the ends using a hammer, drill one hole each at each end, and fix SS nuts and bolts. This is your dipole. Make one more identical square pipe, flatten the ends, drill holes, and tie the ends TOGETHER using a single nut and bolt. This is your reflector (rather than tying up the ends you can add a "stub" on the reflector to improve efficiency). Now mount the dipole and reflector on a frame made by PVC pipes. The distance between the dipole and reflector has an exact value which depends on the station wavelength (forgot again..pl google to find out!).

Impedance matching: Unlike the YAGI, the Quad antenna has an impedance of 75 Ohms. Therefore connect a long 75 Ohm BNC cable to the dipole (the flat cable typically used with TV antennas has an impedance of 300 Ohms) and connect the other end to the antenna input of your FM radio. Now raise the Quad antenna to a good height and point it towards the station. Move it around until you get signal in the radio. A radio with analog tuner is better for this purpose.

Signal amplification: If necessary you can amplify the signal but you will need an amplifier for the FM band with 75 Ohm input and output impedances (The usual "TV antenna boosters" have 300 Ohm impedances).

The above method is the best for catching terrestrial FM transmission. If you are lucky you will get the signal, otherwise not.

Method 2:

Use the VHF Yagi antenna available in the market, flat cable, and TV antenna booster. Even though the frequency won't be an exact match, you may still get signal because of the booster.

Method 3: (My preference)

Go the DTH way. Insat 4B is freely beaming all government radio and TV stations to the Indian subcontinent from a geostationary orbit. Get a local technician and install dish+LNB+cable+FTA satellite receiver for Doordarshan (I think the DTH service of Doordarshan is called DD Plus). Connect the output of the FTA satellite receiver (I recommend receivers from the company "SOLID") to a good quality desktop stereo amplifier (I suggest the 2.1 stereo model F&D A110). You will get some FM stations, all Akashvani AM stations, and all Doordarshan channels in digital quality, without any noise, under a total cost of Rs. 5000 (moreover DD Plus is free, there are no monthly charges). In digital transmission AM sounds as good as FM. Believe me, in the long run your parents will certainly like this radio, because AM radio stations have a great nostalgic value for the older generation. I have this digital radio set up for my wife in our apartment kitchen and she absolutely loves it!

Cheers,

Reji

Thanks a lot for ur insides,

I am more interested in MEthod 2,3 ..
In method 3, if i connect the STD cable from DD directly to FM receiver .. what will happen

 

[manniraj]

Thanks a lot for ur insides,

I am more interested in MEthod 2,3 ..
In method 3, if i connect the STD cable from DD directly to FM receiver .. what will happen

Hehe nothing might happen (or it could blow up ) as the DTH signals need to be decoded and that can be done by the STB. Also with this option for changing of the channels you need a display or else may be a set top box which provides a display with the channel numbers.

 

[sgautam]

Thanks Philipreji for the detailed info, i think that would be the best option if budget is not an option. Only hitch may be with elders not liking to fiddle with additional displays needed to change statios. My search to gift a good radio option to my father almost ended with the fantastic grundig field radio that i got from eBay Canada. Ofcourse it was a costly option but father was thrilled when he saw it and uses it daily now.



I am still searching to improve fm vividbarathi reception at my hometown and the aerial distance to fm tower is only 70-80km. I tried yagi and t type diapole options but the reception is good only early morning or late nights.



Easiest option is to get a good fm tuner and attach the antenna, the SQ will be best is stand alone tuners are used. My friend has Norge tuner, it was OK but compared to my Denon the SQ was not that good. It was bit bright but reception was very good. If budget is not a constraint Yamaha RS201 may be a good option.



Pl keep us updated with your efforts and success, I will be following it keenly. Thanks

 

[philipreji]

Thanks a lot for ur insides,

I am more interested in MEthod 2,3 ..
In method 3, if i connect the STD cable from DD directly to FM receiver .. what will happen

Nothing. The Ku-band downlink frequencies of Insat 4B lie between 10.95 to 11.70 GHz. Data is digital. An FM receiver cannot decode this: A Free-to-air (FTA) satellite receiver is required instead. Input to the receiver is the cable from dish+LNB, and the output is usually analog audio/video through RCA connectors. More expensive receivers (spend Rs.1500 more!) will have digital co-axial and/or HDMI outputs.

cheers,

Reji

 

[philipreji]

Thanks Philipreji for the detailed info, i think that would be the best option if budget is not an option. Only hitch may be with elders not liking to fiddle with additional displays needed to change statios. My search to gift a good radio option to my father almost ended with the fantastic grundig field radio that i got from eBay Canada. Ofcourse it was a costly option but father was thrilled when he saw it and uses it daily now.



I am still searching to improve fm vividbarathi reception at my hometown and the aerial distance to fm tower is only 70-80km. I tried yagi and t type diapole options but the reception is good only early morning or late nights.



Easiest option is to get a good fm tuner and attach the antenna, the SQ will be best is stand alone tuners are used. My friend has Norge tuner, it was OK but compared to my Denon the SQ was not that good. It was bit bright but reception was very good. If budget is not a constraint Yamaha RS201 may be a good option.



Pl keep us updated with your efforts and success, I will be following it keenly. Thanks

Hi Gautam,

You are right: elders are from the analog era when remote controls were mostly unheard of, and rotary knobs and switches controlled almost every radio and TV. However, it is not that difficult to change stations on my "SOLID" FTA receiver: the push button on the unit is rather straightforward if one does not want to use the remote. And the display is just the channel number, nothing more.

Your father is lucky. I would have loved to have a Grundig Field Radio! In 1993 I had bought a 10 band AM/FM pocket radio from Munich, which was great to enjoy the German FM stations broadcasting classical music (through headphones), during my home-university-home walks which typically lasted 30 minutes each way.

I am not sure DD Direct Plus is beaming Vividbharthi FM. The full list is here: DD Free Dish Frequency Wise Channels List | DD Free Dish (DD Direct Plus). There are 92 free channels (TV+Radio). However if you are more interested in catching terrestrial FM transmission, pay serious attention to the antenna design. 70-80 km aerial distance can be challenging even for good FM receivers. Build a uni-directional Yagi antenna which resonates exactly to your station frequency, and use flat cable. Connecting the cable to the radio's antenna input needs care; you may perhaps need a "300 Ohm to 75 Ohm "balun" transformer" for impedance matching. If this also doesn't help, try including a TV antenna booster in the cable line. In case you try these, I will be very keen to know the result!

I have Denon and Marantz AVRs but never quite tried FM radio in them, as I am pretty happy with our DIY DTH kitchen radio. I know a good carpenter and recently I had an interesting idea: get an old valve radio from somewhere and salvage the wooden body, dial, rotary knobs, and magic eye. Remove the innards and fix the FTA receiver in it. Add a DIY/kit stereo amplifier board, two 4" speaker drivers, and new grill cloth. Laminate/polish the wooden body to a new shine. Voila! my "valve radio" is ready, to adorn the living room...if I ever happen to do this I will post a photo hyeah:

cheers,

Reji

 

[philipreji]

Thanks Philipreji. I have been looking at the DTH option for radio and your analysis reinforces mine also. I am keen on AM and especially if you can get AM from across states it is a really boon. Will try to figure out the localally available ones. If any FM has details on where SOLID is available in bangalore, it will help,

thanks!

Hi Gopib,

One of the SOLID models is available in Ebay (Free TO AIR Solid SD 921 Digital SET TOP BOX With USB PVR Recorder | eBay) for Rs.1150/-. I bought mine in 2012, from "Purohit Electronics" in SP Road (another model with MPEG4 decoding and HDMI output; cost was about Rs. 2000 then). You can get all AIR AM stations (all Indian languages), some FM stations, and all Doordarshan TV channels free of cost. SOLID is just one brand (good one), there are other brands too. The instruction manual of SOLID is not that great by the way. Good Luck! Let us know once you install your DTH radio at home!

cheers,

Reji