Topics

Reception of C band - Problem #aero

Patrick Lindecker
 

Hello to all,

 

Today, I tried to receive C band from 3F5, with a 1.1 m diameter dish, applying the diagram (for a possible “Easy” document), below.

I received absolutely no signal on the expected C band frequencies (tested with SDR# and Multipsk). I checked that I could receive L band signals from this satellite (with the same RTL/SDR receiver, a LNA and a patch antenna) and this works well.

I checked the voltage on the LNBF which was correct (about 18 V but it’s true that I did not checked the quality of the filtering). If you have ideas of possible causes of problem, don’t hesitate.

 

Note: when I switched on the LNBF with the 18 V, the level on the SDR# waterfall increases of about 10 dB (which is reassuring).

 

73

Patrick

 

 




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L'absence de virus dans ce courrier électronique a été vérifiée par le logiciel antivirus Avast.
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Paul Gulliver
 

Hi Patrick,
 I've been receiving 3F5 all day so I can confirm there is no problem with the satellite.
Have you tried reversing the polarity, applying 12 volts instead of 18. I notice if the dielectric is in the wrong slots within the lnb this has the same effect as changing the voltage. Ie reversing the polarity. 
 I can't think of anything else that could cause the problem as you have the dish aligned correctly.
What time of day did you try? I always find the strongest signal is when the satellite is above the equator, at the moment between 06.00 and 12.00 gmt 

Cheers

Paul

On Wed, 26 Dec 2018, 17:05 Patrick Lindecker <f6cte@... wrote:

Hello to all,

 

Today, I tried to receive C band from 3F5, with a 1.1 m diameter dish, applying the diagram (for a possible “Easy” document), below.

I received absolutely no signal on the expected C band frequencies (tested with SDR# and Multipsk). I checked that I could receive L band signals from this satellite (with the same RTL/SDR receiver, a LNA and a patch antenna) and this works well.

I checked the voltage on the LNBF which was correct (about 18 V but it’s true that I did not checked the quality of the filtering). If you have ideas of possible causes of problem, don’t hesitate.

 

Note: when I switched on the LNBF with the 18 V, the level on the SDR# waterfall increases of about 10 dB (which is reassuring).

 

73

Patrick

 

 




Avast logo

L'absence de virus dans ce courrier électronique a été vérifiée par le logiciel antivirus Avast.
www.avast.com


Patrick Lindecker
 

Hello Paul,

 

TKS for the advice.

Yes I tried to reverse polarity, but there was no effect ( I tried also to remove the dielectric without any effect).

 

I tried this afternoon. But I received the L band transmissions so I suppose that I could have received the C band.

 

I wonder if my LNB works. But it is difficult to test it because 3.6 GHz sources are rare.

 

>as you have the dish aligned correctly.

I have a compass for azimuth and a setting at about 10 ° of elevation is not a big problem (there is a raw indicator of the dish). My alignment was perhaps at +/-5 ° maximum, in azimuth and elevation, but I don’t think it needs to be extremely precise (in general I get a first signal and then try to adjust elevation and azimuth so to have the maximum signal). But here I had no signal at all.

 

73

Patrick

 

De : multipsk@groups.io [mailto:multipsk@groups.io] De la part de Paul Gulliver
Envoyé : mercredi 26 décembre 2018 21:57
À : multipsk@groups.io
Objet : Re: [multipsk] Reception of C band - Problem #AERO

 

Hi Patrick,

 I've been receiving 3F5 all day so I can confirm there is no problem with the satellite.

Have you tried reversing the polarity, applying 12 volts instead of 18. I notice if the dielectric is in the wrong slots within the lnb this has the same effect as changing the voltage. Ie reversing the polarity. 

 I can't think of anything else that could cause the problem as you have the dish aligned correctly.

What time of day did you try? I always find the strongest signal is when the satellite is above the equator, at the moment between 06.00 and 12.00 gmt 

 

Cheers

 

Paul

 

On Wed, 26 Dec 2018, 17:05 Patrick Lindecker <f6cte@... wrote:

Hello to all,

 

Today, I tried to receive C band from 3F5, with a 1.1 m diameter dish, applying the diagram (for a possible “Easy” document), below.

I received absolutely no signal on the expected C band frequencies (tested with SDR# and Multipsk). I checked that I could receive L band signals from this satellite (with the same RTL/SDR receiver, a LNA and a patch antenna) and this works well.

I checked the voltage on the LNBF which was correct (about 18 V but it’s true that I did not checked the quality of the filtering). If you have ideas of possible causes of problem, don’t hesitate.

 

Note: when I switched on the LNBF with the 18 V, the level on the SDR# waterfall increases of about 10 dB (which is reassuring).

 

73

Patrick

 

 

 


Avast logo

L'absence de virus dans ce courrier électronique a été vérifiée par le logiciel antivirus Avast.
www.avast.com



Chris van Lint
 

Hi Patrick,

Just 2 comments; what is a TERRA P1010 polarity switch?.  Is it a commercial Bias-tee unit with a built-in filter?.  Is the filter a SAW filter or an LC unit?

If you have a signal source that goes up to 2GHz, you can easily obtain up tp 4.0 GHZ, by using a passive RF doubler  https://www.ebay.com/itm/RF-microwave-frequency-doubler-RFin-1-25-3GHz-RFout-2-50-6GHz/182972166464?hash=item2a99fdb140:g:jTwAAOSwlptaOSCR:rk:3:pf:0   

There are losses of course, but for this purpose that is not an issue.

Cheers,

C


At 03:05 AM 27/12/2018, you wrote:
Hello to all,
 
Today, I tried to receive C band from 3F5, with a 1.1 m diameter dish, applying the diagram (for a possible “Easy� document), below.
I received absolutely no signal on the expected C band frequencies (tested with SDR# and Multipsk). I checked that I could receive L band signals from this satellite (with the same RTL/SDR receiver, a LNA and a patch antenna) and this works well.
I checked the voltage on the LNBF which was correct (about 18 V but it’s true that I did not checked the quality of the filtering). If you have ideas of possible causes of problem, don’t hesitate.
 
Note: when I switched on the LNBF with the 18 V, the level on the SDR# waterfall increases of about 10 dB (which is reassuring).
 
73
Patrick
 
[]
 



Avast logo  

L'absence de virus dans ce courrier électronique a été vérifiée par le logiciel antivirus Avast.
www.avast.com

Paul Gulliver
 

Hi Patrick,

Just re-reading your original post, did you align your dish with your L band antenna, this is what I do, I fix my L band helix in place of the LNB and carry out basic alignment and then put the LNB back in place.
I usually have to tweak the alignment to maximise the C-band signal. I take my receiving laptop outside and have it next to my dish and watch the signal strength as I tweaking.

Regarding precision, yes with a 1.1m dish the signal is weak at best so you do have to be accurate, I find just 2 or 3 degrees off can make a big difference - I also notice on my off set dish, the indicator scale on the dish has no relation to reality, it's showing around 30  deg elevation when it's actually pointing around 10 degrees - by looks alone the dish appears to be pointing into the ground but this is a feature of being "off set".

I can't help you with the testing of the LNB but the increase in noise level when you apply power must be a good sign, I get the same effect

Hope you have better luck today, as I write this I have around 50 aircraft showing on my Plane Plotter map - all from my own data.

Cheers

Paul


On 26/12/2018 at 21:50, Patrick Lindecker <f6cte@...> wrote:

Hello Paul,

 

TKS for the advice.

Yes I tried to reverse polarity, but there was no effect ( I tried also to remove the dielectric without any effect).

 

I tried this afternoon. But I received the L band transmissions so I suppose that I could have received the C band.

 

I wonder if my LNB works. But it is difficult to test it because 3.6 GHz sources are rare.

 

>as you have the dish aligned correctly.

I have a compass for azimuth and a setting at about 10 ° of elevation is not a big problem (there is a raw indicator of the dish). My alignment was perhaps at +/-5 ° maximum, in azimuth and elevation, but I don’t think it needs to be extremely precise (in general I get a first signal and then try to adjust elevation and azimuth so to have the maximum signal). But here I had no signal at all.

 

73

Patrick

 

De : multipsk@groups.io [mailto:multipsk@groups.io] De la part de Paul Gulliver
Envoyé : mercredi 26 décembre 2018 21:57
À : multipsk@groups.io
Objet : Re: [multipsk] Reception of C band - Problem #AERO

 

Hi Patrick,

 I've been receiving 3F5 all day so I can confirm there is no problem with the satellite.

Have you tried reversing the polarity, applying 12 volts instead of 18. I notice if the dielectric is in the wrong slots within the lnb this has the same effect as changing the voltage. Ie reversing the polarity. 

 I can't think of anything else that could cause the problem as you have the dish aligned correctly.

What time of day did you try? I always find the strongest signal is when the satellite is above the equator, at the moment between 06.00 and 12.00 gmt 

 

Cheers

 

Paul

 

On Wed, 26 Dec 2018, 17:05 Patrick Lindecker <f6cte@... wrote:

Hello to all,

 

Today, I tried to receive C band from 3F5, with a 1.1 m diameter dish, applying the diagram (for a possible “Easy” document), below.

I received absolutely no signal on the expected C band frequencies (tested with SDR# and Multipsk). I checked that I could receive L band signals from this satellite (with the same RTL/SDR receiver, a LNA and a patch antenna) and this works well.

I checked the voltage on the LNBF which was correct (about 18 V but it’s true that I did not checked the quality of the filtering). If you have ideas of possible causes of problem, don’t hesitate.

 

Note: when I switched on the LNBF with the 18 V, the level on the SDR# waterfall increases of about 10 dB (which is reassuring).

 

73

Patrick

 

 

 


Avast logo

L'absence de virus dans ce courrier électronique a été vérifiée par le logiciel antivirus Avast.
www.avast.com




Patrick Lindecker
 

Hello Chris,

 

Up to yesterday, I thought that the TERRA P1010 also filtered the 18V but I dismounted it today and there is no capacity, so it is just a polarity switch (14/18 + 22 KHz).

I just measure the continuous voltage and the residual alternative voltage, with the LNB in charge. I find respectively 17.5 V and 0.04 V (rms) for these voltages. It seems correct, doesn’t it?

 

RR for the doubler. My only source is my HF transceiver. I will add a diode between the output and the 50 ohm resistive load, as usual, to produce harmonics (of 30 MHz). I will see what happens.

 

73

Patrick

 

 

De : multipsk@groups.io [mailto:multipsk@groups.io] De la part de Chris van Lint
Envoyé : jeudi 27 décembre 2018 02:23
À : multipsk@groups.io
Objet : Re: [multipsk] Reception of C band - Problem #AERO

 

Hi Patrick,

Just 2 comments; what is a TERRA P1010 polarity switch?.  Is it a commercial Bias-tee unit with a built-in filter?.  Is the filter a SAW filter or an LC unit?

If you have a signal source that goes up to 2GHz, you can easily obtain up tp 4.0 GHZ, by using a passive RF doubler  https://www.ebay.com/itm/RF-microwave-frequency-doubler-RFin-1-25-3GHz-RFout-2-50-6GHz/182972166464?hash=item2a99fdb140:g:jTwAAOSwlptaOSCR:rk:3:pf:0   

There are losses of course, but for this purpose that is not an issue.

Cheers,

C


At 03:05 AM 27/12/2018, you wrote:

Hello to all,
 
Today, I tried to receive C band from 3F5, with a 1.1 m diameter dish, applying the diagram (for a possible “Easy†document), below.
I received absolutely no signal on the expected C band frequencies (tested with SDR# and Multipsk). I checked that I could receive L band signals from this satellite (with the same RTL/SDR receiver, a LNA and a patch antenna) and this works well.
I checked the voltage on the LNBF which was correct (about 18 V but it’s true that I did not checked the quality of the filtering). If you have ideas of possible causes of problem, don’t hesitate.
 
Note: when I switched on the LNBF with the 18 V, the level on the SDR# waterfall increases of about 10 dB (which is reassuring).
 
73
Patrick
 
[]
 


Avast logo 

L'absence de virus dans ce courrier électronique a été vérifiée par le logiciel antivirus Avast.
www.avast.com




Avast logo

L'absence de virus dans ce courrier électronique a été vérifiée par le logiciel antivirus Avast.
www.avast.com


Patrick Lindecker
 

Hello Paul,

 

>Just re-reading your original post, did you align your dish with your L band antenna, this is what I do, I fix my L band helix in place of the LNB and carry out basic alignment and then put the LNB back in >place. I usually have to tweak the alignment to maximise the C-band signal. I take my receiving laptop outside and have it next to my dish and watch the signal strength as I tweaking.

I will try to apply your method next time (fixing my poor helix antenna for L band).

 

>Regarding precision, yes with a 1.1m dish the signal is weak at best so you do have to be accurate, I find just 2 or 3 degrees off can make a big difference - I also notice on my off set dish, the indicator >scale on the dish has no relation to reality, it's showing around 30  deg elevation when it's actually pointing around 10 degrees - by looks alone the dish appears to be pointing into the ground but this is a >feature of being "off set".

My method is the following for elevation: I place my offset dish in vertical position, note the index on the dish indicator and rotate the dish by 10° according to the dish indicator. I hope it is a correct way to do for an offset dish (?).

With a gap of 5° compared to the ideal pointing (in azimuth and elevation), do you see at least a weak signal (from which you can refine the pointing) or no signal at all?

 

>Hope you have better luck today,

I must go into my sister garden as I have no direct vision of 3F5 (only 4AF4), so it is a bit complicated ☺.

 

73

Patrick

 

De : multipsk@groups.io [mailto:multipsk@groups.io] De la part de Paul Gulliver
Envoyé : jeudi 27 décembre 2018 10:29
À : multipsk@groups.io
Objet : Re: [multipsk] Reception of C band - Problem #AERO

 

Hi Patrick,

 

Just re-reading your original post, did you align your dish with your L band antenna, this is what I do, I fix my L band helix in place of the LNB and carry out basic alignment and then put the LNB back in place.

I usually have to tweak the alignment to maximise the C-band signal. I take my receiving laptop outside and have it next to my dish and watch the signal strength as I tweaking.

 

Regarding precision, yes with a 1.1m dish the signal is weak at best so you do have to be accurate, I find just 2 or 3 degrees off can make a big difference - I also notice on my off set dish, the indicator scale on the dish has no relation to reality, it's showing around 30  deg elevation when it's actually pointing around 10 degrees - by looks alone the dish appears to be pointing into the ground but this is a feature of being "off set".

 

I can't help you with the testing of the LNB but the increase in noise level when you apply power must be a good sign, I get the same effect

 

Hope you have better luck today, as I write this I have around 50 aircraft showing on my Plane Plotter map - all from my own data.

 

Cheers

 

Paul

 

On 26/12/2018 at 21:50, Patrick Lindecker <f6cte@...> wrote:

Hello Paul,

 

TKS for the advice.

Yes I tried to reverse polarity, but there was no effect ( I tried also to remove the dielectric without any effect).

 

I tried this afternoon. But I received the L band transmissions so I suppose that I could have received the C band.

 

I wonder if my LNB works. But it is difficult to test it because 3.6 GHz sources are rare.

 

>as you have the dish aligned correctly.

I have a compass for azimuth and a setting at about 10 ° of elevation is not a big problem (there is a raw indicator of the dish). My alignment was perhaps at +/-5 ° maximum, in azimuth and elevation, but I don’t think it needs to be extremely precise (in general I get a first signal and then try to adjust elevation and azimuth so to have the maximum signal). But here I had no signal at all.

 

73

Patrick

 

De : multipsk@groups.io [mailto:multipsk@groups.io] De la part de Paul Gulliver
Envoyé : mercredi 26 décembre 2018 21:57
À : multipsk@groups.io
Objet : Re: [multipsk] Reception of C band - Problem #AERO

 

Hi Patrick,

 I've been receiving 3F5 all day so I can confirm there is no problem with the satellite.

Have you tried reversing the polarity, applying 12 volts instead of 18. I notice if the dielectric is in the wrong slots within the lnb this has the same effect as changing the voltage. Ie reversing the polarity. 

 I can't think of anything else that could cause the problem as you have the dish aligned correctly.

What time of day did you try? I always find the strongest signal is when the satellite is above the equator, at the moment between 06.00 and 12.00 gmt 

 

Cheers

 

Paul

 

On Wed, 26 Dec 2018, 17:05 Patrick Lindecker <f6cte@... wrote:

Hello to all,

 

Today, I tried to receive C band from 3F5, with a 1.1 m diameter dish, applying the diagram (for a possible “Easy” document), below.

I received absolutely no signal on the expected C band frequencies (tested with SDR# and Multipsk). I checked that I could receive L band signals from this satellite (with the same RTL/SDR receiver, a LNA and a patch antenna) and this works well.

I checked the voltage on the LNBF which was correct (about 18 V but it’s true that I did not checked the quality of the filtering). If you have ideas of possible causes of problem, don’t hesitate.

 

Note: when I switched on the LNBF with the 18 V, the level on the SDR# waterfall increases of about 10 dB (which is reassuring).

 

73

Patrick

 

 

 


Avast logo

L'absence de virus dans ce courrier électronique a été vérifiée par le logiciel antivirus Avast.
www.avast.com

 

 

Paul Gulliver
 

Patrick,

My method is the following for elevation: I place my offset dish in vertical position, note the index on the dish indicator and rotate the dish by 10° according to the dish indicator. I hope it is a correct way to do for an offset dish (?).

I think this works with prime focus dishes but not off set dishes - I found this article which may help to explain - although I'm not suggesting your dish is off set by 22 deg - but this is just an example


As I mentioned before my dish appears to look down below the horizontal. Perhaps the idea for you would be to get the Azimuth correct, align the dish to look horizontally (dish edges vertical) and then lower the elevation in small amounts until a signal appears ( the frequencies I'm looking at are 1533.92 and 1534.46MHz - subject to variations in the LNB local oscillator)

Keep trying, I'm sure you will succeed in the end  :)

Paul



On 27/12/2018 at 11:06, Patrick Lindecker <f6cte@...> wrote:

Hello Paul,

 

>Just re-reading your original post, did you align your dish with your L band antenna, this is what I do, I fix my L band helix in place of the LNB and carry out basic alignment and then put the LNB back in >place. I usually have to tweak the alignment to maximise the C-band signal. I take my receiving laptop outside and have it next to my dish and watch the signal strength as I tweaking.

I will try to apply your method next time (fixing my poor helix antenna for L band).

 

>Regarding precision, yes with a 1.1m dish the signal is weak at best so you do have to be accurate, I find just 2 or 3 degrees off can make a big difference - I also notice on my off set dish, the indicator >scale on the dish has no relation to reality, it's showing around 30  deg elevation when it's actually pointing around 10 degrees - by looks alone the dish appears to be pointing into the ground but this is a >feature of being "off set".

My method is the following for elevation: I place my offset dish in vertical position, note the index on the dish indicator and rotate the dish by 10° according to the dish indicator. I hope it is a correct way to do for an offset dish (?).

With a gap of 5° compared to the ideal pointing (in azimuth and elevation), do you see at least a weak signal (from which you can refine the pointing) or no signal at all?

 

>Hope you have better luck today,

I must go into my sister garden as I have no direct vision of 3F5 (only 4AF4), so it is a bit complicated ☺.

 

73


Paul Gulliver
 

Ok, so I got curious, I attached a plumb line to the top rim of my dish and measured the gap at the bottom, this gave me an angle of 8 deg.
The dish was set to give an optimum signal at around midday so that would suggest the satellite was around 14 deg elevation and that my dish has an off set angle of 22 degrees just as in the link I posted earlier.
So perhaps 22 deg is a standard for off set dishes?
Anyway Patrick, just to confirm, my dish is pointing downwards (below the horizontal) of about 8 degrees although this will vary by around +- 4 degrees depending on the satellite orbit.

Hope this helps,


Paul

Patrick Lindecker
 

Hello Paul and Chris,

 

Thanks for this interesting (and fundamental) information Paul. According to the paper, I’m going to install the dish upside down so to point towards 10+22=32° instead 10-22=-12° which seems not possible (the mast will prevent this).

 

With my transceiver on 28.125 MHz on TX and the output power towards a diode (a quick diode), I have generated harmonics of 28,125 MHz up to 3600 MHz (28.125x2, x4 , x8, x16…, x128 and surely more). I tested the LNB. It well detects the 3600 MHz MHz  transmission on 1550 MHz (so the LNB works). More curious, the RTL/SDR V3 receives also the 3600 MHz transmission (I thought it was death above 1800 MHz), but not so well as the LNB.

 

Chris, there are electrolytic condensers in the Terra P1010 but they are not of a big value (220 uF). I tried a 2200 uF one but it changes little the residual 50 Hz, so I will leave as it is.

 

73

Patrick

 

 

De : multipsk@groups.io [mailto:multipsk@groups.io] De la part de Paul Gulliver
Envoyé : jeud
i 27 décembre 2018 14:30
À : multipsk@groups.io
Objet : Re: [multipsk] Reception of C band - Problem #AERO

 

Patrick,

 

My method is the following for elevation: I place my offset dish in vertical position, note the index on the dish indicator and rotate the dish by 10° according to the dish indicator. I hope it is a correct way to do for an offset dish (?).

 

I think this works with prime focus dishes but not off set dishes - I found this article which may help to explain - although I'm not suggesting your dish is off set by 22 deg - but this is just an example

 

 

As I mentioned before my dish appears to look down below the horizontal. Perhaps the idea for you would be to get the Azimuth correct, align the dish to look horizontally (dish edges vertical) and then lower the elevation in small amounts until a signal appears ( the frequencies I'm looking at are 1533.92 and 1534.46MHz - subject to variations in the LNB local oscillator)

 

Keep trying, I'm sure you will succeed in the end  :)

 

Paul

 

 

 

On 27/12/2018 at 11:06, Patrick Lindecker <f6cte@...> wrote:

Hello Paul,

 

>Just re-reading your original post, did you align your dish with your L band antenna, this is what I do, I fix my L band helix in place of the LNB and carry out basic alignment and then put the LNB back in >place. I usually have to tweak the alignment to maximise the C-band signal. I take my receiving laptop outside and have it next to my dish and watch the signal strength as I tweaking.

I will try to apply your method next time (fixing my poor helix antenna for L band).

 

>Regarding precision, yes with a 1.1m dish the signal is weak at best so you do have to be accurate, I find just 2 or 3 degrees off can make a big difference - I also notice on my off set dish, the indicator >scale on the dish has no relation to reality, it's showing around 30  deg elevation when it's actually pointing around 10 degrees - by looks alone the dish appears to be pointing into the ground but this is a >feature of being "off set".

My method is the following for elevation: I place my offset dish in vertical position, note the index on the dish indicator and rotate the dish by 10° according to the dish indicator. I hope it is a correct way to do for an offset dish (?).

With a gap of 5° compared to the ideal pointing (in azimuth and elevation), do you see at least a weak signal (from which you can refine the pointing) or no signal at all?

 

>Hope you have better luck today,

I must go into my sister garden as I have no direct vision of 3F5 (only 4AF4), so it is a bit complicated ☺.

 

73

 




Avast logo

L'absence de virus dans ce courrier électronique a été vérifiée par le logiciel antivirus Avast.
www.avast.com


Chris van Lint
 

Hi Patrick,

I agree with Paul.  This is almost certainly a dish alignment issue.  I have no experience with aligning offset dishes, but I can tell you that for 4F! it is impossible to get a usable AERO signal with a 1.2m prime focus dish.  If you scan around a little, you should perhaps find some other stronger signals.  On 4F1 I can find some TV transmissions, which are useful to align the dish.

73 Chris


At 08:51 PM 27/12/2018, you wrote:
Hello Chris,
 
Up to yesterday, I thought that the TERRA P1010 also filtered the 18V but I dismounted it today and there is no capacity, so it is just a polarity switch (14/18 + 22 KHz).
I just measure the continuous voltage and the residual alternative voltage, with the LNB in charge. I find respectively 17.5 V and 0.04 V (rms) for these voltages. It seems correct, doesn’t it?
 
RR for the doubler. My only source is my HF transceiver. I will add a diode between the output and the 50 ohm resistive load, as usual, to produce harmonics (of 30 MHz). I will see what happens.
 
73
Patrick
 
 

Chris van Lint
 

Hi Patrick,

All understood.  The ripple you measured on the 18V rail is negligible and will be filtered out inside the LNB.  I hope you will have some success with your revised alignment procedure.

C


At 03:16 AM 28/12/2018, you wrote:
Hello Paul and Chris,
 
Thanks for this interesting (and fundamental) information Paul. According to the paper, I’m going to install the dish upside down so to point towards 10+22=32° instead 10-22=-12° which seems not possible (the mast will prevent this).
 
With my transceiver on 28.125 MHz on TX and the output power towards a diode (a quick diode), I have generated harmonics of 28,125 MHz up to 3600 MHz (28.125x2, x4 , x8, x16…, x128 and surely more). I tested the LNB. It well detects the 3600 MHz MHz  transmission on 1550 MHz (so the LNB works). More curious, the RTL/SDR V3 receives also the 3600 MHz transmission (I thought it was death above 1800 MHz), but not so well as the LNB.
 
Chris, there are electrolytic condensers in the Terra P1010 but they are not of a big value (220 uF). I tried a 2200 uF one but it changes little the residual 50 Hz, so I will leave as it is.
 
73
Patrick
 
 

Patrick Lindecker
 

Thanks for the advises Chris.

 

73

Patrick

 

De : multipsk@groups.io [mailto:multipsk@groups.io] De la part de Chris van Lint
Envoyé : vendredi 28 décembre 2018 09:04
À : multipsk@groups.io
Objet : Re: [multipsk] Reception of C band - Problem #AERO

 

Hi Patrick,

All understood.  The ripple you measured on the 18V rail is negligible and will be filtered out inside the LNB.  I hope you will have some success with your revised alignment procedure.

C


At 03:16 AM 28/12/2018, you wrote:

Hello Paul and Chris,
 
Thanks for this interesting (and fundamental) information Paul. According to the paper, I’m going to install the dish upside down so to point towards 10+22=32° instead 10-22=-12° which seems not possible (the mast will prevent this).
 
With my transceiver on 28.125 MHz on TX and the output power towards a diode (a quick diode), I have generated harmonics of 28,125 MHz up to 3600 MHz (28.125x2, x4 , x8, x16…, x128 and surely more). I tested the LNB. It well detects the 3600 MHz MHz  transmission on 1550 MHz (so the LNB works). More curious, the RTL/SDR V3 receives also the 3600 MHz transmission (I thought it was death above 1800 MHz), but not so well as the LNB.
 
Chris, there are electrolytic condensers in the Terra P1010 but they are not of a big value (220 uF). I tried a 2200 uF one but it changes little the residual 50 Hz, so I will leave as it is.
 
73
Patrick
 
 




Avast logo

L'absence de virus dans ce courrier électronique a été vérifiée par le logiciel antivirus Avast.
www.avast.com


Patrick Lindecker
 

Hello Chris and Paul ,

 

I have just finished my (last) test towards 3F5 in AERO C band. For pointing, I used both methods:

·         the one of Paul using an helix antenna on L band, replacing the LNB by the helix  antenna,

·         the one of Chris, using a broad band transmission that I found around 1499,7 MHz (at LNB output).

 

Both methods work, but I did not see (nor even guess) any signals between 1534 MHz and 1535 MHz (nor in the vicinity).

 

I suppose that, here, a 2 m dish would be necessary (I used a 1,1 m diameter offset dish).

 

73

Patrick

 

 

De : multipsk@groups.io [mailto:multipsk@groups.io] De la part de Chris van Lint
Envoyé : vendredi 28 décembre 2018 09:04
À : multipsk@groups.io
Objet : Re: [multipsk] Reception of C band - Problem #AERO

 

Hi Patrick,

All understood.  The ripple you measured on the 18V rail is negligible and will be filtered out inside the LNB.  I hope you will have some success with your revised alignment procedure.

C


At 03:16 AM 28/12/2018, you wrote:

Hello Paul and Chris,
 
Thanks for this interesting (and fundamental) information Paul. According to the paper, I’m going to install the dish upside down so to point towards 10+22=32° instead 10-22=-12° which seems not possible (the mast will prevent this).
 
With my transceiver on 28.125 MHz on TX and the output power towards a diode (a quick diode), I have generated harmonics of 28,125 MHz up to 3600 MHz (28.125x2, x4 , x8, x16…, x128 and surely more). I tested the LNB. It well detects the 3600 MHz MHz  transmission on 1550 MHz (so the LNB works). More curious, the RTL/SDR V3 receives also the 3600 MHz transmission (I thought it was death above 1800 MHz), but not so well as the LNB.
 
Chris, there are electrolytic condensers in the Terra P1010 but they are not of a big value (220 uF). I tried a 2200 uF one but it changes little the residual 50 Hz, so I will leave as it is.
 
73
Patrick
 
 




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Paul Gulliver
 

Hi Patrick

Well that's rather disappointing, I have to say I'm a bit surprised you could see no signal at all.
I don't know what part of France you're in but I wouldn't have thought the signal strength would be much less than from here in South UK (your dish size is the same as mine - also offset).
The problem with a larger is dish is that it demands more accurate pointing which in turn makes it more difficult to find the signal.
I find it difficult to believe you're going to give up that easily :)  - There, I've thrown down the challenge for you to give it another go :)

Cheers,


Paul


On 29/12/2018 at 16:54, Patrick Lindecker <f6cte@...> wrote:

Hello Chris and Paul ,

 

I have just finished my (last) test towards 3F5 in AERO C band. For pointing, I used both methods:

·         the one of Paul using an helix antenna on L band, replacing the LNB by the helix  antenna,

·         the one of Chris, using a broad band transmission that I found around 1499,7 MHz (at LNB output).

 

Both methods work, but I did not see (nor even guess) any signals between 1534 MHz and 1535 MHz (nor in the vicinity).

 

I suppose that, here, a 2 m dish would be necessary (I used a 1,1 m diameter offset dish).

 

73

Patrick

 


Patrick Lindecker
 

Hello Paul,

 

>I don't know what part of France you're in but I wouldn't have thought the signal strength would be much less than from here in South UK (your dish size is the same as mine - also offset).

I’m in the immediate south-east of Paris.

 

Hervé in the North of France receives also the C band transmissions. There must be a certain zone where the signal is comfortable and decreasing outside.

 

>I find it difficult to believe you're going to give up that easily :)  - There, I've thrown down the challenge for you to give it another go :)

No it would be the same (and I’m not going to purchase a 2 m dish). And it’s better to know that, with a 1.1 m dish, it is perhaps possible to monitor C band, but not everywhere: south of England and North of France (if Hervé confirms that he receives 3F5) as far as I know.

 

Thanks for your help.

 

73

Patrick

 

 

De : multipsk@groups.io [mailto:multipsk@groups.io] De la part de Paul Gulliver
Envoyé : samedi 29 décembre 2018 18:35
À : multipsk@groups.io
Objet : Re: [multipsk] Reception of C band - Problem #AERO

 

Hi Patrick

 

Well that's rather disappointing, I have to say I'm a bit surprised you could see no signal at all.

I don't know what part of France you're in but I wouldn't have thought the signal strength would be much less than from here in South UK (your dish size is the same as mine - also offset).

The problem with a larger is dish is that it demands more accurate pointing which in turn makes it more difficult to find the signal.

I find it difficult to believe you're going to give up that easily :)  - There, I've thrown down the challenge for you to give it another go :)

 

Cheers,

 

 

Paul

 

On 29/12/2018 at 16:54, Patrick Lindecker <f6cte@...> wrote:

Hello Chris and Paul ,

 

I have just finished my (last) test towards 3F5 in AERO C band. For pointing, I used both methods:

·         the one of Paul using an helix antenna on L band, replacing the LNB by the helix  antenna,

·         the one of Chris, using a broad band transmission that I found around 1499,7 MHz (at LNB output).

 

Both methods work, but I did not see (nor even guess) any signals between 1534 MHz and 1535 MHz (nor in the vicinity).

 

I suppose that, here, a 2 m dish would be necessary (I used a 1,1 m diameter offset dish).

 

73

Patrick

 

 




Avast logo

L'absence de virus dans ce courrier électronique a été vérifiée par le logiciel antivirus Avast.
www.avast.com