Re help with Eitelsat 10


brian foster
 

Hello all. New to Eumetcast. Can anyone tell me what transponder is the best to find eutelsat 10 please. I tried to find ot but all i found was everyone but the one i need . I do have a satfinder meter with spec analyser but not sure if i am on the best transponder. Lots of conflicting frequencies on the net. I have a 1.2 m dish with universal lnb.Thanks


Ernst Lobsiger
 

On Tue, May 18, 2021 at 08:57 PM, brian foster wrote:
Hello all. New to Eumetcast. Can anyone tell me what transponder is the best to find eutelsat 10 please. I tried to find ot but all i found was everyone but the one i need . I do have a satfinder meter with spec analyser but not sure if i am on the best transponder. Lots of conflicting frequencies on the net. I have a 1.2 m dish with universal lnb.Thanks
Brian,

if this is for EUMETCast why you don't directly look for what we usually call T1 (Basic Service + HVS-1) 11263 H (Transponder C4 on Eutelsat 10A)?
You can also take some transponder close to C4. EUMETSAT has an "Antenna pointing guide" online. FlySat and DishPointer sites are helpful as well:

https://www-cdn.eumetsat.int/files/2020-04/pdf_eumetcast_anten_point_guide.pdf

https://www.flysat.com/e10a.php

https://www.dishpointer.com


Hope this helps,
Ernst




Hendrik Fleming
 

IMHO instead of looking and waiting for transponder-lock, a better and quicker way, if you have a spectrum analyzer, is just to look for the beacon. For Eutelsat 10, the beacon is at 10950MHz. 


David J Taylor GM8ARV 🏴󠁧󠁢󠁳󠁣󠁴󠁿 🇪🇺
 

On 29/05/2021 21:57, Hendrik Fleming wrote:
IMHO instead of looking and waiting for transponder-lock, a better and quicker way, if you have a spectrum analyzer, is just to look for the beacon. For Eutelsat 10, the beacon is at 10950MHz.
Or, if you don't happen to have a 10 GHz spectrum analyser, use the "loop out" feed from your cheap TBS5925 and send it to an RTL-SDR dongle. Here I'm using SDR# as the receiver software. Not surprisingly, my LNB doesn't deliver exactly the expected 1,200 MHz beacon IF. I used BDADataEx to set the LNB for horizontal polarisation.

Nice strong signal, though!

Be sure to do your final adjustments to optimise the link margin especially if want to take HVS-2.

Cheers,
David
--
SatSignal Software - Quality software for you
Web: https://www.satsignal.eu
Email: david-taylor@blueyonder.co.uk
Twitter: @gm8arv


diogenes1@...
 

Hello all and particularly David. My LNB is an Inverto with an input, I think, of 10.7-11.7GHz giving an output of 0.950 - 1.950GHz. If the beacon is transmitting on 10.95GHz why is its output frequency 1.2GHz and not a lower frequency? I can only guess that the relationship between the output and input frequencies is not linear but follows some peculiar curve - just a guess.

Regards, Peter

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30 May 2021, 08:25 by david-taylor@...:

On 29/05/2021 21:57, Hendrik Fleming wrote:
IMHO instead of looking and waiting for transponder-lock, a better and quicker way, if you have a spectrum analyzer, is just to look for the beacon. For Eutelsat 10, the beacon is at 10950MHz.

Or, if you don't happen to have a 10 GHz spectrum analyser, use the "loop out" feed from your cheap TBS5925 and send it to an RTL-SDR dongle. Here I'm using SDR# as the receiver software. Not surprisingly, my LNB doesn't deliver exactly the expected 1,200 MHz beacon IF. I used BDADataEx to set the LNB for horizontal polarisation.

Nice strong signal, though!

Be sure to do your final adjustments to optimise the link margin especially if want to take HVS-2.

Cheers,
David
--
SatSignal Software - Quality software for you
Web: https://www.satsignal.eu
Email: david-taylor@...
Twitter: @gm8arv





Ernst Lobsiger
 

Peter,

Your LNB has a LOW band with Input 10.7 ..11.70 GHz using a Local Oscillator frequency of LO=9.75GHz. Your output is Intermediate Frequency IF = Input - LO    (= 950..1950MHz)
Your LNB has a HIGH band with Input 11.7 ..12.75 GHz using a Local Oscillator frequency of LO=10.6GHz. Your output is Intermediate Frequency IF = Input - LO    (=1100..2150MHz)

LOW and HIGH band is switched with 0 and 22KHz tone (by your receiver, EUMETCast T1,T2 is LOW band)
Vertical and Horizontal polarisation is switched with 13V = V and 18V=H (power supplied by your TC receiver)

Hope this helps
Ernst


diogenes1@...
 

Thank you Ernst, I was more or less aware of that but I was trying to get my head around why the beacon frequency of 10.95GHz comes out as the frequency of 1.2GHz in David's image, I was trying to fathom the relationship between the dish receiving frequency and the frequency from the LNB after down convertion which appears at my computer. In other words how can you calculate the frequency output of the LNB from the input frequency received at the dish, which is certainly not a linear relationship.

Regards, Peter


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30 May 2021, 13:13 by ernst.lobsiger@...:

Peter,

Your LNB has a LOW band with Input 10.7 ..11.70 GHz using a Local Oscillator frequency of LO=9.75GHz. Your output is Intermediate Frequency IF = Input - LO    (= 950..1950MHz)
Your LNB has a HIGH band with Input 11.7 ..12.75 GHz using a Local Oscillator frequency of LO=10.6GHz. Your output is Intermediate Frequency IF = Input - LO    (=1100..2150MHz)

LOW and HIGH band is switched with 0 and 22KHz tone (by your receiver, EUMETCast T1,T2 is LOW band)
Vertical and Horizontal polarisation is switched with 13V = V and 18V=H (power supplied by your TC receiver)

Hope this helps
Ernst


Ernst Lobsiger
 

On Sun, May 30, 2021 at 05:31 AM, <diogenes1@...> wrote:
In other words how can you calculate the frequency output of the LNB from the input frequency received at the dish, which is certainly not a linear relationship.
Peter,

that's exactly what I explained. You get:   IF = 10.95GHZ - 9.75GHz = 1.2GHz

Ernst


diogenes1@...
 

Ernst, I now get it, all I need to do is subtract the intermediate frequency from the dish received frequency. Thank you, I am still trying to make sense of things as I zimmer into my eighties.

Regards, Peter


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30 May 2021, 13:38 by ernst.lobsiger@...:

On Sun, May 30, 2021 at 05:31 AM, <diogenes1@...> wrote:

In other words how can you calculate the frequency output of the LNB from the input frequency received at the dish, which is certainly not a linear relationship.
Peter,

that's exactly what I explained. You get:   IF = 10.95GHZ - 9.75GHz = 1.2GHz

Ernst


David J Taylor GM8ARV 🏴󠁧󠁢󠁳󠁣󠁴󠁿 🇪🇺
 

On 30/05/2021 12:51, diogenes1 via groups.io wrote:
Hello all and particularly David. My LNB is an Inverto with an input, I think, of 10.7-11.7GHz giving an output of 0.950 - 1.950GHz. If the beacon is transmitting on 10.95GHz why is its output frequency 1.2GHz and not a lower frequency? I can only guess that the relationship between the output and input frequencies is not linear but follows some peculiar curve - just a guess.
Regards, Peter
Peter,

The LO is 9750 Mhz, so the IF is 10950 - 9750 => 1.3 GHz. The LO is on the low side.


https://en.wikipedia.org/wiki/Low-noise_block_downconverter#Universal_LNB_(%22Astra%22_LNB)

Also, taking your values:
if 10700 in gives 950 MHz out
then 10950 (i.e. 10700 + 250) gives 1200 MHz (i.e.950 +250)

Cheers,
David
--
SatSignal Software - Quality software for you
Web: https://www.satsignal.eu
Email: david-taylor@blueyonder.co.uk
Twitter: @gm8arv


diogenes1@...
 

Hello David, between Ernst and yourself it is now clear to me. I am ashamed to say that as a Radio Amateur I should have known this but time and memory are great levellers.

Regards, Peter


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30 May 2021, 13:46 by david-taylor@...:

On 30/05/2021 12:51, diogenes1 via groups.io wrote:
Hello all and particularly David. My LNB is an Inverto with an input, I think, of 10.7-11.7GHz giving an output of 0.950 - 1.950GHz. If the beacon is transmitting on 10.95GHz why is its output frequency 1.2GHz and not a lower frequency? I can only guess that the relationship between the output and input frequencies is not linear but follows some peculiar curve - just a guess.

Regards, Peter

Peter,

The LO is 9750 Mhz, so the IF is 10950 - 9750 => 1.3 GHz. The LO is on the low side.


https://en.wikipedia.org/wiki/Low-noise_block_downconverter#Universal_LNB_(%22Astra%22_LNB)

Also, taking your values:
if 10700 in gives 950 MHz out
then 10950 (i.e. 10700 + 250) gives 1200 MHz (i.e.950 +250)

Cheers,
David
--
SatSignal Software - Quality software for you
Web: https://www.satsignal.eu
Email: david-taylor@...
Twitter: @gm8arv





David J Taylor GM8ARV 🏴󠁧󠁢󠁳󠁣󠁴󠁿 🇪🇺
 

On 30/05/2021 13:46, David J Taylor GM8ARV 🏴 🇪🇺 via groups.io wrote:
The LO is 9750 Mhz, so the IF is 10950 - 9750 => 1.3 GHz. The LO is on
the low side.
For those following this: s/1.3/1.2/

David
--
SatSignal Software - Quality software for you
Web: https://www.satsignal.eu
Email: david-taylor@blueyonder.co.uk
Twitter: @gm8arv


Ernst Lobsiger
 

On Sun, May 30, 2021 at 05:47 AM, <diogenes1@...> wrote:
Ernst, I now get it, all I need to do is subtract the intermediate frequency from the dish received frequency. Thank you, I am still trying to make sense of things as I zimmer into my eighties.
Peter,

no problem but it's the LO frequency that you have to subtract from the frequency that comes from the satellite down to your dish. The result is the downconverted Intermediate Frequency (IF). The IF comes to your receiver via coax cable and F-plugs. The LO frequency is generated in your LNB by a device called Local Oscillator (probably quarz stabilized). Yes, we are all getting older, I had to find my cheat sheet first and David also just had his "s/1.3/1.2/"   (= replace 1.3 by 1.2).

Ernst


David J Taylor GM8ARV 🏴󠁧󠁢󠁳󠁣󠁴󠁿 🇪🇺
 

On 30/05/2021 14:00, diogenes1 via groups.io wrote:
Hello David, between Ernst and yourself it is now clear to me. I am ashamed to say that as a Radio Amateur I should have known this but time and memory are great levellers.
Regards, Peter
Peter,

I find these days I am more willing to say "I don't understand" or to ask for an explanation. I often hear other say: "I'm glad you asked that..."

David,
GM8ARV

--
SatSignal Software - Quality software for you
Web: https://www.satsignal.eu
Email: david-taylor@blueyonder.co.uk
Twitter: @gm8arv


Bfost
 

Thanks guys for all your help on this. David, i too have to say i dont know. But thanks for all the help.
If i get stuck. I will ask again.. Thanks..Brian de M0CNQ.

On 30 May 2021, at 15:05, David J Taylor GM8ARV 🏴󠁧󠁢󠁳󠁣󠁴󠁿 🇪🇺 via groups.io <david-taylor=blueyonder.co.uk@groups.io> wrote:

On 30/05/2021 14:00, diogenes1 via groups.io wrote:
Hello David, between Ernst and yourself it is now clear to me. I am ashamed to say that as a Radio Amateur I should have known this but time and memory are great levellers.
Regards, Peter
Peter,

I find these days I am more willing to say "I don't understand" or to ask for an explanation. I often hear other say: "I'm glad you asked that..."

David,
GM8ARV

--
SatSignal Software - Quality software for you
Web: https://www.satsignal.eu
Email: david-taylor@blueyonder.co.uk
Twitter: @gm8arv