Message: 1 Date: Wed, 2 Sep 2009 19:24:00 -0700 (PDT) From: Vickram Crishna <[email protected]>
Hello All, Since Nomad engineers have installed and re-analysed the problem faced by Dr Rego, I would like to share following observations: 1. The transmitter is generating exactly 50 watts of power as stipulated by the Government. 2. The antenna is giving the stipulated gain (approx 2.8 dBi) while coax length is less than 10 meters. 3. The SWR is less than 1.1 4. System is not generating any noise or spurious. Some crackling sound is being picked up in air. 5. Signals are reaching as long as 15 to 20 km if you ignore the noise 5. All problems are sorted out if we operate anywhere else in the frequency band Possible reasons: 1. Spurious and harmonic interference from other RF systems, may not necessarily radio stations. 2. Very high levels of moisture due to monsoon season. Possible solutions: 1. Change the Frequency to 90.4 as given to many other community radio stations. 2. As it has been discussed before CRF should request WPC to avoid alloting 107.8 to low powered radio stations. Hope this helps. in solidarity Hemant Subject: Re: [cr-india] on frequency To: CR India <[email protected]> Message-ID: <[email protected]> Content-Type: text/plain; charset="utf-8" Dr Rego There are two possible problems. One is that your own transmitter is not generating sufficient EIRP, which could be due to an antenna mismatch. The second, and more likely, is that other stations nearby are generating spurious signals at your allotted frequency band. As you report, they 'invade' your space. According to you, 'checking' for the cause only got you the answer 'frequency' - who gave you this answer? If it is anyone from the Ministry (telecom or broadcasting)/WPC, then perhaps you need to file an RTI asking them for copies of orders given to the other stations to repair their setup. It would also be useful to track the actual status of transmission during your broadcast timings, and also at other times, in order to establish whether your bandwidth is being cluttered by spurious signals from other nearby stations. Finally, is there a chance that you are located too close to the transmission towers of any other stations? The SACFA clearance was supposed to take care of this aspect, of course. Vickram http://communicall.wordpress.com http://vvcrishna.wordpress.com ________________________________ From: Dr Richie Rego SJ <[email protected]> To: CR Forum <[email protected]> Sent: Wednesday, 2 September, 2009 22:57:35 Subject: [cr-india] on frequency Hi everyone! I have a problem. Would like to know how you would deal with this - we have 107.8 MHz frequency assigned to us. But low power radio sets and mobiles cannot receive our radio signals even in nearby areas - car stereo do. That means, local communities are deprived of our transmission. People keep pleading us "increase signals" - they have listened to our station sometime; they have read in newspapers. hence their demand. We are unable because of the frequency. We checked why this happens. The answer is 'frequency'. In addition - noise! Besides, private FMs and AIR keep invading our frequency gloriously. All Our efforts and people's desire doesn't seem to be bearing fruit. How would be address this problem? I will try uploading an audio piece recorded from our own transmitter in our own campus & in the vicinity of the College. You can feel the noise and difference. If I succeed, the piece should be available through my blog www.richardrego.wordpress.com for you to get a taste. TC ==================================== Rev Dr Richard Rego SJ Director, SARANG SAC 107.8FM Community Radio Head & Asst Prof., MCMS Dept of Mass Communication St Aloysius College; P.B. 720 Mangalore - 575003. www.richardrego.wordpress.com www.staloysiuscollege.wordpress.com 0824-2449706. +919448546425. -------------- next part -------------- An HTML attachment was scrubbed... URL: http://mail.sarai.net/pipermail/cr-india/attachments/20090902/4c2c2f98/attachment-0001.html -------------- next part -------------- A non-text attachment was scrubbed... Name: not available Type: image/jpeg Size: 12322 bytes Desc: not available Url : http://mail.sarai.net/pipermail/cr-india/attachments/20090902/4c2c2f98/attachment-0001.jpe ------------------------------ Message: 2 Date: Thu, 3 Sep 2009 14:17:14 +0530 From: mahesh acharya <[email protected]> Subject: Re: [cr-india] on frequency To: Dr Richie Rego SJ <[email protected]> Cc: CR Forum <[email protected]> Message-ID: <[email protected]> Content-Type: text/plain; charset="iso-8859-1" Dear Dr. Richie, What is the transmitter output? and where is the transmitter located? CR policy allows to use max 250watt transmitter. However this will not assure that everybody will be able to hear the broadcast (the receiver should be in broadcast zone) but will improve the situation a bit. The other option is to put repeater(s) where the signal reception is poor. You will have to seek permission from Wireless Planning Commsn to do this by building a strong case. (audio recording etc) *Some antenna basics * Omnidirectional Antenna's radiate power uniformally in all directions. Other types of transmissions are unidirectional radiating more power in one direction (usually the direction of antenna that is pointed). In terms of range difference omni directional will have small range of reception. Uni's range of rcption will b more. Music systems in cars cannot recve the broadcast for the fact that they do not have telescopic antenna (the ones u have on stand alone radio sets) and since output of sarang may is in watts compared to kilowatts (kilo=1000) mobile phones will not rcve the broadcast at all unless they are very very close to transmitter. Solution: Listeners will have to use telescopic antenna for the radio in music system. Using headphones in mobile may improve the situation a bit as headphones act as antenna. Radio sets that are not able to recve good quality audio can be improved if they point the telescopic antenna in the direction of the transmitter. Keeping the set near window will also help in some cases. Regarding FM and AIR invading the freq, this may not be possible in all the radio sets. Some poor quality radio sets will recve strongest signals even though you have tuned to freq that you want to listen. There is some degree of separation between freq's assigned by WPC and thus some sets rcvng only FM and AIR may be true but not all. FM and AIR were were already present b4 sarang was assigned the freq. I could be wrong and in case all the radio sets are rcvng FM and AIR, then the matter should be taken up with WPC and I am sure they will look into it. Hope this helps. regards, mahesh vu3mbv * * On Wed, Sep 2, 2009 at 10:57 PM, Dr Richie Rego SJ <[email protected]>wrote: > Hi everyone! > > I have a problem. Would like to know how you would deal with this - we have > 107.8 MHz frequency assigned to us. But low power radio sets and mobiles > cannot receive our radio signals even in nearby areas - car stereo do. That > means, local communities are deprived of our transmission. People keep > pleading us "increase signals" - they have listened to our station sometime; > they have read in newspapers. hence their demand. We are unable because of > the frequency. We checked why this happens. The answer is 'frequency'. In > addition - noise! > > Besides, private FMs and AIR keep invading our frequency gloriously. All > Our efforts and people's desire doesn't seem to be bearing fruit. > > How would be address this problem? > I will try uploading an audio piece recorded from our own transmitter in > our own campus & in the vicinity of the College. You can feel the noise and > difference. > > If I succeed, the piece should be available through my blog > www.richardrego.wordpress.com for you to get a taste. > TC > > ==================================== > Rev Dr Richard Rego SJ > Director, SARANG SAC 107.8FM Community Radio > Head & Asst Prof., MCMS > Dept of Mass Communication > St Aloysius College; P.B. 720 > Mangalore - 575003. > www.richardrego.wordpress.com > www.staloysiuscollege.wordpress.com > 0824-2449706. > +919448546425. _______________________________________________ cr-india mailing list [email protected] https://mail.sarai.net/mailman/listinfo/cr-india
