Date   

Re: Definitions and questions!

Timestep <Information@...>
 

From: Dave Cawley
Timestep Dartmouth England
e-mail Information@...
Web site http://www.Time-step.com
Tel. +44 (0)1803 833366
Fax. +44 (0)1803 839498

You just can't believe specifications, it probably says +/- 1dB somewhere,
or if not, what is the tolerance ? And anyway, manufactures have been known
to just invent figures, who can prove them wrong, or right ?

Dave


Re: Definitions and questions!

Guy Martin <agm@...>
 

Haven't checked the maker's site myself but do they offer tech support by e-mail, might be worth a try.

Cheers, Guy

----- Original Message -----
From: David Taylor
To: MSG-1@...
Sent: Monday, November 10, 2003 5:29 PM
Subject: [MSG-1] Re: Definitions and questions!


--- In MSG-1@..., "Alan Sewards" <alan.sewards@c...>
wrote:
> David,
> Looks as though the 2.3 card is the more sensitive, taking the
1/2 at 27.7 Ms/s figures, by about 1 dB.
>
> Best regards - Alan

Yes, that was the way I read it as well. I just didn't want to
think that the card I had just replaced was actually better than its
replacement! Presumably this means that you need at least 1dB
greater SNR with the newer card (or USB version) than with the older
card for the same performance. Perhaps it isn't that simple....

Cheers,
David



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Re: Missing segments

David J Taylor GM8ARV 🏴󠁧󠁢󠁳󠁣󠁴󠁿 🇪🇺
 

Sent: Saturday, November 08, 2003 3:57 PM
[]
Modern and cheap meters are just fine. But having looked at several
users
installations I can see the problem. I'll expand on this tomorrow.

Regards

Dave
What are your thoughts, Dave?

David


Re: Definitions and questions!

David J Taylor GM8ARV 🏴󠁧󠁢󠁳󠁣󠁴󠁿 🇪🇺
 

--- In MSG-1@..., "Alan Sewards" <alan.sewards@c...>
wrote:
David,
Looks as though the 2.3 card is the more sensitive, taking the
1/2 at 27.7 Ms/s figures, by about 1 dB.

Best regards - Alan
Yes, that was the way I read it as well. I just didn't want to
think that the card I had just replaced was actually better than its
replacement! Presumably this means that you need at least 1dB
greater SNR with the newer card (or USB version) than with the older
card for the same performance. Perhaps it isn't that simple....

Cheers,
David


Re: Definitions and questions!

Alan Sewards <alan.sewards@...>
 

David,
Looks as though the 2.3 card is the more sensitive, taking the 1/2 at
27.7 Ms/s figures, by about 1 dB.

Best regards - Alan

----- Original Message -----
From: "David Taylor" <david-taylor@...>
To: <MSG-1@...>
Sent: Monday, November 10, 2003 3:20 PM
Subject: [MSG-1] Re: Definitions and questions!


--- In MSG-1@..., "pa3aod" <harms@a...> wrote:
Hi David,

I found some info on the WEB about the B2C2 chip(and software),
look at the following web-pages www.bbti.us and www.b2c2.com.

Bert PA3AOD
Thanks, Bert. I'd found those pages later by searching on B2C2. I
got an outline data sheet on the main chip on the card (FlexCop) and
on the "TechniSat" card (which seems to actually be a B2C2 card).
the plot thickens!

I am trying to get a better undertsanding of how the system works,
and what the so-called quality indicator means. At least in the
data sheet they talk about power (dBm) into a 75 ohm impedance, so I
am on familiar ground there. I haven't yet worked out from the
Eb/No threshold tables whether the 2.3 or the 2.6B is the more
sensitive card!

Cheers,
David

chip: <http://www.b2c2.com/docs/flexcop.pdf>

card:

<http://www.bbti.us/download/documentation/Sky2PC_Product_Specificati
on.pdf>

(beware of URL wrapping)



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Re: Dish

johnrigsec@...
 

In a message dated 07-11-03 04:54:59 GMT Standard Time, a.van.belle@...
writes:

Modern LNB's are only suited for offset dishes. The feedhorn is
different to get a smaller beamwidth, compared to most prime focus
dishes with F/D=0.5 (offsets have F/D of 0.6 to 0.7).

You can put a modern LNB in the focus of a prime focus dish, but you
will only use 40 to 60% of its surface, giving low signal level.
Arne,

Thanks for your useful information.
I knew there was a difference between (early) prime focus RF equipment and
present
day offset equipment but not sure quite what.
I suspect I'm not the only person to learn something new.

My early prime focus LNC's (as they were called in those days) have wider
apertures
and scalar feeds.

But you will be shocked by the noise figure of these oldies, 1.3 to
1.8 was excellent these days !
Nowadays you have 0.6 to 0.7 dB for 1/5 of the price !
Indeed, my first 10/11 GHz LNC from Avantek had a noise figure of 1.8 dB and
cost,
in 1986, £1,200!

Sorry, a bit off topic for MSG, but it was through C-band and Ku-band
satellite TV
that I got into weather satellites.
And the rest, as they say, is history.

One thing, for us in the UK who are only supposed to install ONE dish per
property,
take a look at the ultimate(?) multi satellite dish system at <A HREF="www.wavefrontier.com">
www.wavefrontier.com</A>
you can have your (multiple) satellite, satellite TV and EUMETCast, from one
dish!

Regards,
John.
RIG


[Non-text portions of this message have been removed]


Reception fluctuations

Dave Martin <Dave.Martin@...>
 

just to throw in another idea - I wonder if frequency drift is playing any part here?

The B2C2 receiver cards have a Xtal osc and should be quite stable; but as I understand LNBs they don't have a Xtal oscillator but a "Dielectric Reasonant Oscillator" (DRO) which is not so stable - and, I was wondering, perhaps it is temperature sensitive? (and suffering from the onset of Autumn?)

I haven't been able to confirm anything in my native MSG setup, but, in common with the general scepticism over the "indicators" reported by the Tellique client, have carried out following experiment which led to the above suggestion :

I have tried look at things "raw" from the LNB but spectrum analyser I have which covers those LNB output frequencies wasn't stable enough, so ....

I have an ex-broadcast-relay analog receiver (Intercontinental MT900 / Agile Omni) which has both AFC and AGC which can be manually disabled. It also has metering for Carrier/Noise, Signal Strength, and Tuning; and I have used the signal strength in the past for alignment and watching rain fade. I understand that the "Tune" metering (scaled +/- 2MHz ) is some form of indication for a PLL error signal from the AFC or similar, and normally doesn't vary much - BUT as an experiment, with the receiver tuned to an analog transmission with the AFC off, I tried cooling an old LNB and I got a noticeable change - although with the AFC back on it was more than powerful enough to pull the rx back on tune.

This receiver setup / internal meter is unfortunately not able to directly meter a digital transmission - but I have found a way and it showed the same sensitivity. Even though it couldn't demodulate it, I tuned the receiver to the frequency used for the digital MSG hotbird downlink, and with the receiver bandwidth set to the max 36Mhz I picked-off the 70MHz IF to a Marconi TF2370 s/a - this only goes to 110MHz but is ideal to monitor 70MHz IF and has dual digital storage - storing one trace before cooling and superimposing a second after cooling showed a mass shift of the whole of the 'digital hump' by just over 1MHz.

Perhaps, if the link budget is already marginal, then =maybe= this is contributing - either drifting in&out, or drifting out and the card is then having to re-lock?

Dave M
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Re: missing segments

Alan Sewards <alan.sewards@...>
 

Arne,
I agree with your list except that I did not miss the 1815 cycle
segments. They were not reported as missing in MDM, and the images appear to
be present on the hard disk.

Best regards - Alan

----- Original Message -----
From: "a_van_belle" <a.van.belle@...>
To: <MSG-1@...>
Sent: Sunday, November 09, 2003 11:59 PM
Subject: [MSG-1] Re: missing segments


--- In MSG-1@..., "David Taylor" <david-taylor@b...>
wrote:
Robert, there have been some issues today, but the 16:15 cycle just
completed seems perfect.
Quite some missing segments today.
They could be local but my receive PC has been running well.

Please notify me if someone had less missing segments !
<
snip
<
Cycle: 1815
msg-ch04, seg: 8
lrit-ch01, seg: 8
lrit-ch03, seg: 8
lrit-ch04, seg: 8
Key: msg=HRIT lrit=LRIT
01=VIS006 02=VIS008 03=IR016 04=IR039
05=WV062 06=WV073 07=IR087 08=IR097
09=IR108 10=IR120 11=IR134 12=HRV
_____________________
Missing rebroadcast & derived segments report
Cycle: 0000
g9-ir, seg: 2
Key: gnn=FSD cla=CLA clai=CLAI clm=CLM cth=CTH



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Re: Definitions and questions!

David J Taylor GM8ARV 🏴󠁧󠁢󠁳󠁣󠁴󠁿 🇪🇺
 

I think this might be it.

http://www.semiconductors.philips.com/pip/TDA8060ATS_C2.html

Peter
Not convinced! The package is wrong.

But the two ICs in the tuner are SL1925 (zero-IF demodulator) and
TSA5059 (2.7GHz synthesiser). Perhapss the chip outside the tuner
does the analog to digital demodulation? The FlexCop II chip is
defined in the data sheet. The data sheets for those chips makes
fascinating reading.

Cheers,
David


Re: Definitions and questions!

David J Taylor GM8ARV 🏴󠁧󠁢󠁳󠁣󠁴󠁿 🇪🇺
 

--- In MSG-1@..., "pa3aod" <harms@a...> wrote:
Hi David,

I found some info on the WEB about the B2C2 chip(and software),
look at the following web-pages www.bbti.us and www.b2c2.com.

Bert PA3AOD
Thanks, Bert. I'd found those pages later by searching on B2C2. I
got an outline data sheet on the main chip on the card (FlexCop) and
on the "TechniSat" card (which seems to actually be a B2C2 card).
the plot thickens!

I am trying to get a better undertsanding of how the system works,
and what the so-called quality indicator means. At least in the
data sheet they talk about power (dBm) into a 75 ohm impedance, so I
am on familiar ground there. I haven't yet worked out from the
Eb/No threshold tables whether the 2.3 or the 2.6B is the more
sensitive card!

Cheers,
David

chip: <http://www.b2c2.com/docs/flexcop.pdf>

card:

<http://www.bbti.us/download/documentation/Sky2PC_Product_Specificati
on.pdf>

(beware of URL wrapping)


Re: Definitions and questions!

Peter Benney <tugboat@...>
 

The B2C2 card is purely digitial, so that doesn't
help, I can't find the part number for the tuner, and the chip next
to it is hidden under a heatsink!
David,

I think this might be it.

http://www.semiconductors.philips.com/pip/TDA8060ATS_C2.html

Peter


Re: missing segments

Robert Moore
 

Quoting a_van_belle <a.van.belle@...>:


Robert do you have TV4PC under Start, programs, DVB ?
No and the supplied Tellique disk only lists:
'SkyStar2_4_T-systems_EUMETSAT_data_only'


Robert



David Taylor, now you have version 4.2.8 running with the new setup,
is TV4PC installed by default?

TV4PC is not the only way to view TV, other viewers can be used once
the skystar drivers are installed.
Did anyone else try to install and start DVBviewer after the official
Eumetcast installation procedure?

At my work at this moment, but I will try this evening to get a
viewer working.

Greetings,
Arne van Belle




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------------------------------
Professor Robert Moore
Department of Sociology, Social Policy
and Social Work Studies
The University of Liverpool
Eleanor Rathbone Building
Bedford Street South
Liverpool
L69 7ZA

tel and fax: 44 (0) 1352 714456


Re: Definitions and questions!

pa3aod <harms@...>
 

Hi David,

I found some info on the WEB about the B2C2 chip(and software), look
at the following web-pages www.bbti.us and www.b2c2.com.

Bert PA3AOD



--- In MSG-1@..., "David Taylor" <david-taylor@b...>
wrote:
--- In MSG-1@..., "Alan Sewards" <alan.sewards@c...>
wrote:
David,
Arne and I discussed this on MSG-1 group on 12 October. I'm
am
fairly sure that Signal Quality is a measure of S/N, and probably
improves if a splitter is fitted because of reduction of overload
or
subtle changes in receiver parameters with changes in signal level.
Easiest way to check is to exchange the splitter for an attenuator!

Best regards - Alan
Yes, I found that after a little looking. I have tried to find the
specs of the B2C2 chip and other component of the SkyStar card, in
the hope of finding something more like an engineering manual that
I
could understand! The B2C2 card is purely digitial, so that
doesn't
help, I can't find the part number for the tuner, and the chip next
to it is hidden under a heatsink!

In any case, if all these cards need lower signal strength to
perform well, shouldn't AGC be doing something about that?
Is "our"
transponder being hidden in a mush of intermodulation from the
others?

Cheers,
David


Re: SkyStar card versions - calibration differences?

Peter Benney <tugboat@...>
 

(I should add that I also now have a spliiter so that I can feed two
cards from one antenna. My simplistic view suggests that splitting
the signal should, er, decrease the SNR and not increase it!).
Today I added a splitter and fed the Skystar PCI card and a Digital Satellite Receiver(STB) from the same LNB.

The signal on the STB dropped from 88% to 86% and quality remained at 100% . Setup4PC showed no change in Quality 69-71% but with a slightly more rapid fluctuation. The SNR changed from a steady 10.8 to varying between 10.8 and 11.2. The insertion loss of the splitter is 4dB.

Setup4PC showed no change when connected either via the STB loopthrough or directly to the LNB. An advantage of the loopthrough setup is the ability to monitor a TV channel on the 11096 tp whilst receiving MSG1 data. The motorised dish allows the tweaking of the azimuth with the aid of the more responsive signal and quality indicators of the STB. So far since installation my dish has remained rock steady .

Peter


Re: missing segments

David J Taylor GM8ARV 🏴󠁧󠁢󠁳󠁣󠁴󠁿 🇪🇺
 

David Taylor, now you have version 4.2.8 running with the new
setup, is TV4PC installed by default?

I didn't let it install "Personal Video Recorder" (PVR as I recall),
I went to the Install folder on the CD where there was a setup.exe
and that gave me Server4PC and Setup4PC in the &#92;program
files&#92;TechniSat DVB&#92;bin&#92; folder. This seemed to be enough. Those
files are timestamped 19 August 2003 at 00:30. Server4PC is
V4.2.8.9999 as is Setup4PC. Both files are from "B2C2, Inc".

Unfortunately I don't have a Eumetsat install disk, so I don't know
if these are the correct versions.....

Cheers,
David


Re: missing segments

a_van_belle
 

--- In MSG-1@..., Robert Moore <rsmoore@l...> wrote:
Thank you Arne that is useful to know - I have six to eight
segments missing in
_every_ fifteen minute pass.
Looks like I may have to go up the ladder!
We desperately need a second source to verify our systems.

I did mention this earlier on Satsignal list, by installing the
DVB/tellique software a bit differently it is possible to start TV4PC
and watch TV when TQ is off.
This way you can check if the antenna and Skystar are working
properly by watching Sailing channel. Every signal drop or too low
signal quality will be shown as "freeze" or dropout on a digital TV
channel. Sailing channel is on the same transponder as Eumetcast.

Robert do you have TV4PC under Start, programs, DVB ?
David Taylor, now you have version 4.2.8 running with the new setup,
is TV4PC installed by default?

TV4PC is not the only way to view TV, other viewers can be used once
the skystar drivers are installed.
Did anyone else try to install and start DVBviewer after the official
Eumetcast installation procedure?

At my work at this moment, but I will try this evening to get a
viewer working.

Greetings,
Arne van Belle


Re: Still missing segments!

David J Taylor GM8ARV 🏴󠁧󠁢󠁳󠁣󠁴󠁿 🇪🇺
 

--- In MSG-1@..., Lawrence <lawrence@a...> wrote:
Well, I must admit to being mystified. I have been monitoring the
receive computer and it consistently shows memory usage of about
130Mb (very small proportion) and an average CPU of 1 to 2% with few
jumps. But still I am seeing huge chunks out of the HRIT images.
But not all HRIT images and not every cycle. The signal strength is
excellent.

Lawrence
Lawrence, one common factor in people with missing segments is that
you are all using the MSG Data Manager. Now I don't think that this
is the cause, but one simple check would be to compare the resukts
from the Tools, Missing segments report.. with the actual images.

If the images show the same as the Missing segments report..., then
I belive that the program is decoding everything it sees. If there
are more missing segments in the images than in the report it would
suggest that something in the data stream is faulty, and the program
is refusing to decode the faulty data.

You might also want to check that no HRIT data is being left
unprocessed on the receiver PC. Unlikely, but check.

Cheers,
David


Still missing segments!

Lawrence <lawrence@...>
 

Well, I must admit to being mystified. I have been monitoring the
receive computer and it consistently shows memory usage of about 130Mb
(very small proportion) and an average CPU of 1 to 2% with few jumps.
But still I am seeing huge chunks out of the HRIT images. But not all
HRIT images and not every cycle. The signal strength is excellent.

Lawrence


Re: missing segments

Robert Moore
 

Alan, see my piece in next RIG journal. I have only _one_ place in my whole
house where I can see MSG-1. This requires a pole above roof level, and it was
a very close thing there too.

Robert


Quoting Alan Sewards <alan.sewards@...>:

Why don't you guys put your dishes where they are easily accessible? They
don't get any more signal for being on the roof and they are much more prone
to wind effects. Find a sheltered wall and use a sturdy wall bracket.

Best regards - Alan

----- Original Message -----
From: "Robert Moore" <rsmoore@...>
To: <MSG-1@...>
Sent: Sunday, November 09, 2003 4:59 PM
Subject: [MSG-1] missing segments


David, I've been preoccupied with other things for a few days so have
rather
lost the thread on missing segments. I am still losing enough to make the
system almost unusable and animations impossible. Is there something
happening
that I can do nothing about, or is it time to call in the man the with the
ladder and meter from the local TV shop (costs me �72 a time here in the
hills)?
Best wishes
Robert



in Quoting David Taylor <david-taylor@...>:

--- In MSG-1@..., "Douglas Deans" <douglas@d...> wrote:
I think best just to close down until the channel 2 problem
(started about
midday) is resolved.
No software could deal with this !
Could be worse, Douglas. My eToken on the new PC has stopped
working three time today already! 01:21, 14:08 and 15:04. Stops
all data flow and requires a reboot. At least you don't have that
problem!

Touch wood, the 15:15 is looking OK.

Cheers,
David



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------------------------------
Professor Robert Moore
Department of Sociology, Social Policy
and Social Work Studies
The University of Liverpool
Eleanor Rathbone Building
Bedford Street South
Liverpool
L69 7ZA

tel and fax: 44 (0) 1352 714456


To unsubscribe from this group, send an email to:
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To unsubscribe from this group, send an email to:
MSG-1-unsubscribe@...



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------------------------------
Professor Robert Moore
Department of Sociology, Social Policy
and Social Work Studies
The University of Liverpool
Eleanor Rathbone Building
Bedford Street South
Liverpool
L69 7ZA

tel and fax: 44 (0) 1352 714456


Re: missing segments

Alan Sewards <alan.sewards@...>
 

Why don't you guys put your dishes where they are easily accessible? They
don't get any more signal for being on the roof and they are much more prone
to wind effects. Find a sheltered wall and use a sturdy wall bracket.

Best regards - Alan

----- Original Message -----
From: "Robert Moore" <rsmoore@...>
To: <MSG-1@...>
Sent: Sunday, November 09, 2003 4:59 PM
Subject: [MSG-1] missing segments


David, I've been preoccupied with other things for a few days so have
rather
lost the thread on missing segments. I am still losing enough to make the
system almost unusable and animations impossible. Is there something
happening
that I can do nothing about, or is it time to call in the man the with the
ladder and meter from the local TV shop (costs me �72 a time here in the
hills)?
Best wishes
Robert



in Quoting David Taylor <david-taylor@...>:

--- In MSG-1@..., "Douglas Deans" <douglas@d...> wrote:
I think best just to close down until the channel 2 problem
(started about
midday) is resolved.
No software could deal with this !
Could be worse, Douglas. My eToken on the new PC has stopped
working three time today already! 01:21, 14:08 and 15:04. Stops
all data flow and requires a reboot. At least you don't have that
problem!

Touch wood, the 15:15 is looking OK.

Cheers,
David



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------------------------------
Professor Robert Moore
Department of Sociology, Social Policy
and Social Work Studies
The University of Liverpool
Eleanor Rathbone Building
Bedford Street South
Liverpool
L69 7ZA

tel and fax: 44 (0) 1352 714456


To unsubscribe from this group, send an email to:
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