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Mumbai FM channels in Pune
- Thread starter SVK
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FM stations being received 100-200 KMs away from the originating city is no miracle, just pure electronics. How far the signal will be received depends on:
(1) The power of the transmitter - An FM transmitter is just an electronic device that broadcasts electronic energy. Don't faint, but what it broadcasts is actually electric current. Why we don't get a shock by it as we do with normal electric current in our household, is because the power transmitted by FM stations is so less in comparison. An FM transmitter that broadcasts 10 Watts of current (in form of modulated wave energy), can be heard 100 miles away (aerial distance) or even more. See this: All about FM and AM radio broadcasting: PCS Electronics specially the picture at http://www.pcs-electronics.com/schematics/max1rack2.jpg
(2) Availability of LoS (Line of Sight) - FM Signals travel in straight lines. For best possible reception an LoS is required. A person nearer to the transmitting station may not get as good a reception as person much farther but having a better LoS.
(3) Capability of the receiver - The reception also depends on the capability of the receiver. A good receiver can catch and demodulate signals that an ordinary receiver will simply ignore or won't be able to process.
(4) Electric interference - We don't realize it, but there is so much of electrical interference present in our environment. FM reception, like any other device working on RF waves, is subject to electrical interferences. Take a mobile phone with FM near to a computer's CPU when you are listening to FM, the sound quality will drop considerably, take it away, the signal improves.
In brief, it is absolutely no miracle that Mumbai FM stations can be heard in Pune. I'd say, if you use a good external antenna, you can hear Mumbai FM stations in interiors of Maharashtra.
~ Ranjeet Rain
(1) The power of the transmitter - An FM transmitter is just an electronic device that broadcasts electronic energy. Don't faint, but what it broadcasts is actually electric current. Why we don't get a shock by it as we do with normal electric current in our household, is because the power transmitted by FM stations is so less in comparison. An FM transmitter that broadcasts 10 Watts of current (in form of modulated wave energy), can be heard 100 miles away (aerial distance) or even more. See this: All about FM and AM radio broadcasting: PCS Electronics specially the picture at http://www.pcs-electronics.com/schematics/max1rack2.jpg
(2) Availability of LoS (Line of Sight) - FM Signals travel in straight lines. For best possible reception an LoS is required. A person nearer to the transmitting station may not get as good a reception as person much farther but having a better LoS.
(3) Capability of the receiver - The reception also depends on the capability of the receiver. A good receiver can catch and demodulate signals that an ordinary receiver will simply ignore or won't be able to process.
(4) Electric interference - We don't realize it, but there is so much of electrical interference present in our environment. FM reception, like any other device working on RF waves, is subject to electrical interferences. Take a mobile phone with FM near to a computer's CPU when you are listening to FM, the sound quality will drop considerably, take it away, the signal improves.
In brief, it is absolutely no miracle that Mumbai FM stations can be heard in Pune. I'd say, if you use a good external antenna, you can hear Mumbai FM stations in interiors of Maharashtra.
~ Ranjeet Rain
@Cyberwiz.Yes, technically, FM is better than AM. A radio station piggybacks radio signal to broadcast over a another signal (called carrier, and the process called Modulation). A receiver demodulates the composite signal to seperate the main signal from the carier. In AM broadcast, the varying quantity is the Amplitude, whereas in FM boadcast, its frequency. In both cases the composite signal is susceptible to degradation when it travels far. The difference is that, degradation in apmlitude is more prone to loss than the frequency. Hence, the loss in quality in case of FM transmission is much less than in AM. Obviously, FM generally produces much better sound quality than AM.@netfreak>> I don't think Line of sight goes to 100 or 200 KM. Radius of Earth is 6378.16 KMs. 100 KM divided by 6378.16 KMs is 0.015678 %. Flat enough? 100 KMs is perfectly LoS, when it comes to Earth.>> 1. It has stereo transmissionWhere did you get that from?FM is just a broadcast technology. Whether a radio station uses it for Mono broadcast or stereo, is entirely upto the radio station. Tomorrow, Some radio station may want to broadcast Dolby encoded 5.1 program material in 2 channels stereo over FM. Will that make FM a 5.1 broadcast system?FM is not stereo. FM is usually stereo. It is stereo, if: (1) You are tuned to a station broadcasting in stereo (2) You have a stereo capable receiver (excuse the 35 buck handsets) (3) You have good enough reception for the demodulator to demultiplex the stereo signal. If not, it will act as if the signal were Mono~ Ranjeet Rain
ok...clash of the gaints... delhilama vs netfreak! 
ermm...the range of FM is limited due to:1. Regulations2. Power of transmittersSomewhere in my engineering career I had read that the RANGE of any signal is HIGHLY dependent on the HEIGHT of the antenna 
Now, there is obviously a limitation on how HIGH one can build an antenna. Also, there are regulations in place for civil FM transmission to be restricted between 87.5MHz to 108MHz ( am not sure of the range though ). Higher the frequency, higher the signal power, long is the range of the signal. But due to the regulations the limitation on the range.umm...excuse me delhilama, a radio station does NOT piggyback a radio signal on a carrier.The signal which a radio station generates is a baseband signal. The transmission equipment inside the station generates a high powered carrier signal. The baseband signal is then superimposed on the high frequency carrier by modulating the FREQUENCY ( only in case of FM / PM ) of the carrier. This signal is a radio signal which is then transmitted :yahoo
ont we all love to nitpick?
ermm...the range of FM is limited due to:1. Regulations2. Power of transmittersSomewhere in my engineering career I had read that the RANGE of any signal is HIGHLY dependent on the HEIGHT of the antenna Now, there is obviously a limitation on how HIGH one can build an antenna. Also, there are regulations in place for civil FM transmission to be restricted between 87.5MHz to 108MHz ( am not sure of the range though ). Higher the frequency, higher the signal power, long is the range of the signal. But due to the regulations the limitation on the range.umm...excuse me delhilama, a radio station does NOT piggyback a radio signal on a carrier.The signal which a radio station generates is a baseband signal. The transmission equipment inside the station generates a high powered carrier signal. The baseband signal is then superimposed on the high frequency carrier by modulating the FREQUENCY ( only in case of FM / PM ) of the carrier. This signal is a radio signal which is then transmitted :yahooont we all love to nitpick? Radius of Earth is 6378.16 KMs. 100 KM divided by 6378.16 KMs is 0.015678 %. Flat enough? 100 KMs is perfectly LoS, when it comes to Earth.
Calculation of "line of sight" is bit more complex then that.
This page Line-of-Sight Transmission talk of a method that assumes you are at the same hight as antenna.
This page Math Forum - Ask Dr. Math has a formula that does not make this assumption.
So if height of antenna is 100 meters and your receiver is 2 meters high, line of sight will be 41 km.
Even if you are on 20th floor of a building (approx 100 meters), LOS will be 71 km.
This is the Excel formula : =SQRT(C6^2 + 2*C6*C5) +SQRT(C7^2 + 2*C7*C5)
C5 -- Radius
C6 -- Height of Antenna
C7 -- height of Receiver
Everything is in meters
FM is just a broadcast technology. Whether a radio station uses it for Mono broadcast or stereo, is entirely upto the radio station.
Standard FM broadcast equipment is "Stereo Enabled"
Standard AM broadcast equipment is NOT "Stereo Enabled"
Is that specific enough?
Calculation of "line of sight" is bit more complex then that.
This page Line-of-Sight Transmission talk of a method that assumes you are at the same hight as antenna.
This page Math Forum - Ask Dr. Math has a formula that does not make this assumption.
So if height of antenna is 100 meters and your receiver is 2 meters high, line of sight will be 41 km.
Even if you are on 20th floor of a building (approx 100 meters), LOS will be 71 km.
This is the Excel formula : =SQRT(C6^2 + 2*C6*C5) +SQRT(C7^2 + 2*C7*C5)
C5 -- Radius
C6 -- Height of Antenna
C7 -- height of Receiver
Everything is in meters
FM is just a broadcast technology. Whether a radio station uses it for Mono broadcast or stereo, is entirely upto the radio station.
Standard FM broadcast equipment is "Stereo Enabled"
Standard AM broadcast equipment is NOT "Stereo Enabled"
Is that specific enough?