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Old 13th July 2007, 11:16   #106
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Even I thought they dont' use lossy formats for over the air broadcast.

MP2 is better than MP3 at higher bit rates, I think.
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Old 13th July 2007, 13:16   #107
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Originally Posted by DerAlte View Post
Dunno, something to do with storage and random access (rapid track call-up, as in RAM).
Didn't think about it, never put myself into RJ's shoes!


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Operational predicaments, predates PC polularity. DVDs are fairly recent in all this, and are not naturally associated with audio.
Yes, agree.
BTW, I came to know about mp3s and started using them in around 96-97, when I guess it was far from being popular (here in India). I used to get excited about playing some music in college labs!

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never the studio end (except a few times in AIR Akashvani Bhavan ages back).
I had visited an Akashvani AM station about 15 years back. That was probably the most dead silent place I have ever been to. No idea about how today's FM stations look like (except for "salam namaste"!).

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FM stations are not Studios. A Recording Studio is a Studio. The equipment at each of these is quite different (a few like BBC being exceptions).
OK ok, got it. But they are still called "studios" for whatever reasons and aren't their equipments of top-notch quality, at least by consumer standards? If they were equivalent to recording studios, then I would expect nothing less than master copies (BTW, I presume here that these big recording companies must be having some sort of treasured golden records, superior to CDs lauched in market)

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MP2 was adapted as it was the best at that time and they dont have any great need to change given that the music is dynamically compressed before being aired anyway.
Given today's state of advances in PCs, storage devices and their cost effectiveness, I hope they would have upgraded to something like lossless (FLAC/wavepack/monkes's audio) or simply plain WAV/RIFF (depending upon how cash-strapped they are). I am not too sure about my judgment but yes, I do notice lack of dynamics in FM music. But then I also believe even most of the CDs that people buy are heavily compressed to make them loud, right?



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DJ's would often walk into a booth with milk bottle crates of LPs (atleast I did).
That sounds funny! So, you have been a DJ/RJ for radio stations? Where?
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Old 16th July 2007, 19:44   #108
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Originally Posted by tsk1979 View Post
Wow thats news.
Could you share your setup
Which receiver and which antenna?
By reading these threads, I was bit interested to try the setup in my car. I went to one of the WS dealer in HYD and bought the BPL OneWorld Receiver with 6 Months Subscription. When I bought this it was raining outside and I could not dare the keep the Antenna on the roof top of my car. I just kept the Antenna on my Dash, plugged the AV output to the Aux in of the HU and switched on the receiver, put the PW and Wow it worked... I was impressed with the Sound Quality and the content of the WS Channels. It was sounding great with my JBL Setup. One can easily differentiate between the quality of the Local FM Stations and WS Stations. It was mind blowing. As of now, all I was doing the setup in an open area and kept the Antenna in High Position(180 Degree from Base, refer the pic about Antenna Positioning) to wards South Direction on the Dash. After the setup was complete I went for a drive, believe me I went all the direction and roamed around Hitec City and nearby area, I was getting uninterrupted Signal, the music was rocking. I observed, when there was a huge Building or tree, The signal used to break and after 4-5 seconds, the Signal was back again. Just once or twice, I had to rotate the Antenna Little bit.

I have kept the Antenna and Receiver on the dash and Once I get some time, I am planning to fix it permanently. HYD TBHPian(or any one visits HYD), if want to see the setup and experience the WS in a Moving car, PM me, I will be happy to take you on a ride. I work in Cyberpearl Building in Hitec City.

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Old 16th July 2007, 21:06   #109
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hey sys_whiz, thats great news.
But I suggest you measure the dipole size(supplied antenna). This will tell you the frequency. Based on the frequency you can easily create a J-pole etc., omnidirectional antenna which you can mount anywhere without worrying about rain.
So I think Worldspace will work in cars in an open area!
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Old 16th July 2007, 21:56   #110
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Quote:
Originally Posted by sys whiz
When I bought this it was raining outside and I could not dare the keep the Antenna on the roof top of my car.
Do you have the black antenna, with the rectangular receiver ? This one is weather proof - my antenna is outside, completely exposed, and I have not had any problems atall.
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Old 17th July 2007, 01:11   #111
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Originally Posted by tsk1979 View Post
I suggest you measure the dipole size(supplied antenna). This will tell you the frequency. Based on the frequency you can easily create a J-pole etc., omnidirectional antenna which you can mount anywhere without worrying about rain.
Hey tsk, it went above my head, could not understand this very techy terms. If you don't mind, Can you pls explain in details.

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Originally Posted by condor View Post
Do you have the black antenna, with the rectangular receiver ? This one is weather proof - my antenna is outside, completely exposed, and I have not had any problems atall.
Yes Condor, it is a Black Antenna written BPL and Worldspace on the Top. Its a rectangular in shape and fold-able in nature for the angle.
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Old 17th July 2007, 08:04   #112
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Quote:
Originally Posted by sys_whiz
..it is a Black Antenna written BPL and Worldspace on the Top. Its a rectangular in shape and fold-able in nature for the angle.
Got the same one, and it's placed outside for more than a year-and-half now, in the rain & shine.
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Old 17th July 2007, 10:26   #113
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Aree Waah Sys!
You make me a happy man.
Can you please post a pic of your setup? Like they say...A picture is worth a thousand words.....
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Old 17th July 2007, 12:51   #114
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Originally Posted by sys_whiz View Post
Hey tsk, it went above my head, could not understand this very techy terms. If you don't mind, Can you pls explain in details.
Yes Condor, it is a Black Antenna written BPL and Worldspace on the Top. Its a rectangular in shape and fold-able in nature for the angle.
Ok I made it complicated... sorry.
Well its simple.
1. Find out what frequency is the worldspace station range lie in
2. To find this out, you can measure the existing antenna element(Not the whole dish, just the thing in center) or do google for worldspace frequencies or look up the reciever manual.
3. Once you know the range you design an omnidirectional antenna. You can get one for 40$ in the US, but to make one with high grade materials will cost around 100rs and you can mount it outside.


Based on this you will get some reception. Ofcourse you cannot get as good a signal as a "dish antenna" but still you will get the signal.
The advantage is that it will be a small antenna, just like having a FM antenna or something.
If the worldspace signal we get here is weak, this idea will flop, since omnidirectional antennas can never be as good as a dish antenna(uni directional) and then you would need an amplifier.
In the Days Doordarshan remember those small amplifiers which had this knob called gain and if your TV reception was grainy you could turn it clockwise and improve the reception to a certain degree?
Those were amps. You can design such an amp using commonly available transistors for Satellite radio frequency.
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Old 17th July 2007, 13:43   #115
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tsk, Will omni directional antenna overcome line-of-sight (LOS) requirement?
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Old 17th July 2007, 14:04   #116
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Ok I will tell you exact frequency tomorrow (I remember it is L Band ~1200-1400MHz, but will conform this tomorrow). I have both patch antenna and diapole antenna. But both are using LNA attached inline the cable and receiver is suppyling some 5VDC to it through same cable. So I suggest using Omini directional Antenna, be careful.

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Originally Posted by tsk1979 View Post
If the worldspace signal we get here is weak, this idea will flop, since omnidirectional antennas can never be as good as a dish antenna(uni directional) and then you would need an amplifier.
Its really weak. I tried out all of these options and the patch antenna has inbuild LNA (Low Noise Amplifier). With that too its is week once you lose line of site by 10 degrees angle.

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Originally Posted by tsk1979 View Post
You can design such an amp using commonly available transistors for Satellite radio frequency.
guys, we are talking about microwave frequencies. Designing and assembling amplifier for that is too tough as it needs ESD protected, temp controlled soldering and involves components something like GaAs FETs, very tough to get and solder.
Better you buy the LNA from Worldspace with weather proof metal body + connectors (Costs 250 or 280 Rs , dont remember now)

Last edited by tsk1979 : 18th July 2007 at 00:36.
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Old 17th July 2007, 18:15   #117
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Originally Posted by omishra View Post
Its really weak. I tried out all of these options and the patch antenna has inbuild LNA (Low Noise Amplifier)...
guys, we are talking about microwave frequencies. Designing and assembling amplifier for that is too tough ...
Better you buy the LNA from Worldspace with weather proof metal body + connectors (Costs 250 or 280 Rs , dont remember now)
Even the after-market XM / Sirius antennae have LNAs. And yes, building the UHF antenna is non-trivial, even for RF component makers.

Does WS sell the antenna directly to consumers? Or do the receiver manufacturers sell only along with their sets?

Weatherproof antenna? Oops, I must check my antenna today - I had left it conveniently on a window 'sajja' exposed to the elements for the last few years - and never checked. Thanks for the trigger, @omishra.
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Old 18th July 2007, 00:38   #118
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Originally Posted by santosh.s View Post
tsk, Will omni directional antenna overcome line-of-sight (LOS) requirement?
Nope, only to some extent. But you need to have view of the satellite, i.e. where there are treetops, the antenna will fail.
Same way as GPS reception fails on shaded roads sometimes.

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Originally Posted by omishra View Post
Ok I will tell you exact frequency tomorrow (I remember it is L Band ~1200-1400MHz, but will conform this tomorrow). I have both patch antenna and diapole antenna. But both are using LNA attached inline the cable and receiver is suppyling some 5VDC to it through same cable. So I suggest using Omini directional Antenna, be careful.


Its really weak. I tried out all of these options and the patch antenna has inbuild LNA (Low Noise Amplifier). With that too its is week once you lose line of site by 10 degrees angle.


guys, we are talking about microwave frequencies. Designing and assembling amplifier for that is too tough as it needs ESD protected, temp controlled soldering and involves components something like GaAs FETs, very tough to get and solder.
Better you buy the LNA from Worldspace with weather proof metal body + connectors (Costs 250 or 280 Rs , dont remember now)
Do they sell a LNA separately?
I am curious what kind of setup do XM/Siruis have for their In car setups.
If we use a similar LNA and antenna for worldspace, it may work.
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Old 18th July 2007, 10:22   #119
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Originally Posted by tsk1979 View Post
Do they sell a LNA separately?
I am curious what kind of setup do XM/Siruis have for their In car setups.
If we use a similar LNA and antenna for worldspace, it may work.
Yes they sell it separately. After installing Worldspace radio, I noticed that some channels have lower gain. This was due to big tree in LOS. Then I bought Yagi antenna ~400 + ~250 = (~650Rs with LNA) and 20meter cable for 200Rs. But when ever I tried this yagi too off LOS, signal is lost (no success so far).

Frequency for transmission is 1452-1492 MHz
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Old 18th July 2007, 12:50   #120
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Originally Posted by tsk1979 View Post
I am curious what kind of setup do XM/Siruis have for their In car setups.
If we use a similar LNA and antenna for worldspace, it may work.
They look like smaller versions of the WS weatherproof 'box' antenna (not the Yagi). The radio-side connector is 1 or 2 (no idea why 2) small SMC in a block for XM, bare for Sirius.

Haven't seen a native (OEM) XM/Sirius mount in a car. The after-market XM, Sirius and GPS antennas either get mounted on the windscreen or rear glass with a swivel mount, which attaches to the glass with a powerful adhesive. Some of them go on to the dash, parcel-tray top near the bottom of the glass, on the boot cover or on the roof top (like the 'sharkfin' antenna). There are even a couple (like the Delphi Roady)which mount on the air outlets (a la Ambi car perfume!!!).

If the signal is 1.452-1.492 GHz, then the antenna is expected to be rather small. Yagi would not be an advantage, unless we are in really low-signal-strength (fringe) areas. Generally Yagi would be a disadvantage since it is more directional than other antenna types (peak gain in LOS).
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