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Found here all the postings in 2002
FTA_SAT
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Location: Tuzla

Post by FTA_SAT » Sun Nov 17, 2002 6:17 pm

No signal on 11623 H...Thanks to all!

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stanley_cassidy
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Post by stanley_cassidy » Sun Nov 17, 2002 7:06 pm

Fta_sat,very high signal for me on 11623 from South Italy (dish 1.2 metres)

FTA_SAT
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Post by FTA_SAT » Sun Nov 17, 2002 10:36 pm

I have found this!! On 11624 H. At the evening signal is stronger there.

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Cookie-Monster
Mega Feedhunter
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Posts: 7352
Joined: Tue Nov 27, 2001 3:00 pm
satellite: Triax 88 (23W-62E)
Smart MX 04 HDCA (26042010)
Powersky 1900
Nokia 9200
Location: Belgium

Post by Cookie-Monster » Mon Nov 18, 2002 1:22 am

FTA_SAT , can you change the bandwide in the menu ??
I couldn't find anything on:
http://www.samsungelectronics.com/digit ... R_9500.pdf

With my Nokia , no problems all 4 frequencies ,
11620 (FTA) , 11625 , 11630 , 11635 (FTA) ,
I get them without any problem


Ckie Mnster

FTA_SAT
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Post by FTA_SAT » Mon Nov 18, 2002 9:12 pm

It is not possible with Samsung 9500.

Bye

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Cookie-Monster
Mega Feedhunter
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Posts: 7352
Joined: Tue Nov 27, 2001 3:00 pm
satellite: Triax 88 (23W-62E)
Smart MX 04 HDCA (26042010)
Powersky 1900
Nokia 9200
Location: Belgium

Post by Cookie-Monster » Mon Nov 18, 2002 9:23 pm

All 4 channels are NOW encrypted

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Rob
Starting feedhunter
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Posts: 97
Joined: Wed May 29, 2002 10:07 am
Location: Netherlands

Post by Rob » Mon Nov 18, 2002 9:25 pm

From what I have found out so far about the Nokia 9500 (I have a Dbox myself since a couple of weeks), what is called "bandwidth" in the firmware is not the bandwidth of the filters, but the "acquisition bandwidth", which I think is the area around the entered frequency where it will look for signals.
Unfortunately, it is unclear what the units are. So what does "10" or "40" mean? Let's say it means 1 or 4 MHz. That would mean, in my theory, that it will look in an area of 1 or 4 MHz (or maybe 1 or 4 MHz up and down from the entered frequency) to see if the signal is there.
This is done to overcome uncertainties in the frequency, errors in the LNB downmix frequency, etc.
This does not actually affect the receiver performance once a signal is found. You can then readback the actual frequency and store that in the memory.

What you need for good performance at low bitrates is a narrow filter in the receiver. I believe most receivers have only 2 filters, and they switch automatically (one for MCPC signalling rates, say 20000 and above, and one for SCSP (low) signalling rates).
When the signalling rate is really low (like 3333 in this case, sometimes even lower), the filter is too wide and the receiver performance is sub-optimal because it receives noise and adjacent channels. A truely settable filter bandwith (settable via the user interface) is possible, but most likely it is too expensive for a consumer receiver. It would require an extra filter and synthesized oscillator and mixer.

The "acquisition bandwidth" thingy in the Nokia sometimes even causes grief... I have a channel list that can be downloaded from Internet and it lists many feed channels on Eutelsat W2. But when selecting them, often 10 give the same picture. When I look on my XSAT receiver, I see only 1 signal on a certain frequency and symbolrate. But the Nokia starts hunting for the signal on all these channels and they all end up finding a picture on some channel.
(e.g. an ENEX feed is visible on 3-4 of the ENEX channels when the others are clear)

Rob

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Cookie-Monster
Mega Feedhunter
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Posts: 7352
Joined: Tue Nov 27, 2001 3:00 pm
satellite: Triax 88 (23W-62E)
Smart MX 04 HDCA (26042010)
Powersky 1900
Nokia 9200
Location: Belgium

Post by Cookie-Monster » Mon Nov 18, 2002 9:35 pm

I received following information in march 2002 about ACBW:
http://www.sat-benelux.com/files/topic. ... IC_ID=3420


Ckie Mnster

Rob
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Post by Rob » Mon Nov 18, 2002 9:50 pm

quote:
I received following information in march 2002 about ACBW:
http://www.sat-benelux.com/files/topic. ... IC_ID=3420


Ckie Mnster


Ah interesting... so maybe it does switch the filter... but indeed only two filters.
It is easy to see why it does not work well: the filter you need is a bit wider (in MHz) than the QPSK symbolrate. So for 27500 the 36 MHz filter is OK, and for 6110 the 9 MHz filter is fine. But for 3333 there is no suitable filter in the receiver, and you use 9 MHz which is to wide (twice as wide as required).
When there is no stuff around the transmit frequency you see only extra noise, but in this case the transponders are packed close together and the wide filter sees the next channels. This damages the signal and causes the receive problems. Not surprising that everyone has different results, because the receivers probably have different filters.

Rob

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