Excellent.

Yes tuning the dish and feed can be tedious …

Congratulations getting it all right now

Regards

Matthias

www.dd1us.de

So,

I’ve had my dish for two years I think, anyway I’ve never been happy with the received signal strength. I finally around to aligning it today – increased the SNR of the beacons by 8dB, what a difference! Being a 1.4m prime focus dish the 3dB beamwidth is quite small.

Woot – Woot!

Simon Brown, G4ELI

https://www.sdr-radio.com

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My 1.8m dish is quite deep (f/D=0.29)

When I first did some preliminary testing I had it adjusted in 15 minutes and the results were great.

I assumed that I might get even better results when everything was refurbished and at its final position.

When I tried there (on top of the roof of my garage) it took me more than 2 hours to align it and just get back to
the point where I had it during the preliminary test. Finally I managed to squeeze out another 1-2 dBs.

The good news is that my dish is now up and running about 2 years and the results are still the same …

By the way fine tuning is only possible with a DATV receiver tuned to the QO-100 WB beacon.

Kind regards

Matthias

www.dd1us.de

Indeed,

LNB skew, offset from focal point etc – gained ~1.5dB. Elevation 7dB at least.

Excellent.

Yes tuning the dish and feed can be tedious …

Congratulations getting it all right now

Regards

Matthias

www.dd1us.de

So,

I’ve had my dish for two years I think, anyway I’ve never been happy with the received signal strength. I finally around to aligning it today – increased the SNR of the beacons by 8dB, what a difference! Being a 1.4m prime focus dish the 3dB beamwidth is quite small.

Woot – Woot!

Simon Brown, G4ELI

https://www.sdr-radio.com

--

--

Hi Simon,

with your nice dish you should see the NB transponder noise rolling by about 5-6 dB.

Kind regards

Matthias

www.dd1us.de

Hi,

Now I can see the ‘Bloom’ of the NB transponder I’ll look at receiving DATV, I have no idea where to start!

My 1.8m dish is quite deep (f/D=0.29)

When I first did some preliminary testing I had it adjusted in 15 minutes and the results were great.

I assumed that I might get even better results when everything was refurbished and at its final position.

When I tried there (on top of the roof of my garage) it took me more than 2 hours to align it and just get back to
the point where I had it during the preliminary test. Finally I managed to squeeze out another 1-2 dBs.

The good news is that my dish is now up and running about 2 years and the results are still the same …

By the way fine tuning is only possible with a DATV receiver tuned to the QO-100 WB beacon.

Kind regards

Matthias

www.dd1us.de

Indeed,

LNB skew, offset from focal point etc – gained ~1.5dB. Elevation 7dB at least.

Excellent.

Yes tuning the dish and feed can be tedious …

Congratulations getting it all right now

Regards

Matthias

www.dd1us.de

So,

I’ve had my dish for two years I think, anyway I’ve never been happy with the received signal strength. I finally around to aligning it today – increased the SNR of the beacons by 8dB, what a difference! Being a 1.4m prime focus dish the 3dB beamwidth is quite small.

Woot – Woot!

Simon Brown, G4ELI

https://www.sdr-radio.com

--

--

--

Hi Simon,

with your nice dish you should see the NB transponder noise rolling by about 5-6 dB.

Kind regards

Matthias

www.dd1us.de

Hi,

Now I can see the ‘Bloom’ of the NB transponder I’ll look at receiving DATV, I have no idea where to start!

My 1.8m dish is quite deep (f/D=0.29)

When I first did some preliminary testing I had it adjusted in 15 minutes and the results were great.

I assumed that I might get even better results when everything was refurbished and at its final position.

When I tried there (on top of the roof of my garage) it took me more than 2 hours to align it and just get back to
the point where I had it during the preliminary test. Finally I managed to squeeze out another 1-2 dBs.

The good news is that my dish is now up and running about 2 years and the results are still the same …

By the way fine tuning is only possible with a DATV receiver tuned to the QO-100 WB beacon.

Kind regards

Matthias

www.dd1us.de

Indeed,

LNB skew, offset from focal point etc – gained ~1.5dB. Elevation 7dB at least.

Excellent.

Yes tuning the dish and feed can be tedious …

Congratulations getting it all right now

Regards

Matthias

www.dd1us.de

So,

I’ve had my dish for two years I think, anyway I’ve never been happy with the received signal strength. I finally around to aligning it today – increased the SNR of the beacons by 8dB, what a difference! Being a 1.4m prime focus dish the 3dB beamwidth is quite small.

Woot – Woot!

Simon Brown, G4ELI

https://www.sdr-radio.com

--

--

--

There was no attachment / picture attached to your Email.

You know that the polarization of the WB tpx is orthogonal to the NB tpx !?

Regards

Matthias

www.dd1us.de

FWIW here’s what I see. I tuned to the WB transponder – no signals.

I have no idea how good my LNB is.

Hi Simon,

with your nice dish you should see the NB transponder noise rolling by about 5-6 dB.

Kind regards

Matthias

www.dd1us.de

Hi,

Now I can see the ‘Bloom’ of the NB transponder I’ll look at receiving DATV, I have no idea where to start!

My 1.8m dish is quite deep (f/D=0.29)

When I first did some preliminary testing I had it adjusted in 15 minutes and the results were great.

I assumed that I might get even better results when everything was refurbished and at its final position.

When I tried there (on top of the roof of my garage) it took me more than 2 hours to align it and just get back to
the point where I had it during the preliminary test. Finally I managed to squeeze out another 1-2 dBs.

The good news is that my dish is now up and running about 2 years and the results are still the same …

By the way fine tuning is only possible with a DATV receiver tuned to the QO-100 WB beacon.

Kind regards

Matthias

www.dd1us.de

Indeed,

LNB skew, offset from focal point etc – gained ~1.5dB. Elevation 7dB at least.

Excellent.

Yes tuning the dish and feed can be tedious …

Congratulations getting it all right now

Regards

Matthias

www.dd1us.de

So,

I’ve had my dish for two years I think, anyway I’ve never been happy with the received signal strength. I finally around to aligning it today – increased the SNR of the beacons by 8dB, what a difference! Being a 1.4m prime focus dish the 3dB beamwidth is quite small.

Woot – Woot!

Simon Brown, G4ELI

https://www.sdr-radio.com

--

--

--

--

Attachments:

• image003.jpg
• Screenshot-2021-04-01-153600.jpeg

I can receive my own DATV signals sent with under 1 watt. I have a 2.4m dish, That is equivalent to 4W for a 1.2m dish so Simon will have enough EIRP. On receive the difference between a 2.4m and 1.2m dish is under a dB. This is because you are receiving the transponder noise floor and the link limited by the SNR on the uplink. A 30m dish would only be a dB better. Diminishing returns. Simon's dish is in between these so should be getting around 11 dB MER on the DATV beacon. There are various reasons this might not happen, dosh pointing and focus being two but phase noise being a third. Knowing what he has I would think the dish might not be totally optimised. It is easy to tell, measure the noise floor of the narrow band transponder relative to the band just below, there should be an uplift. for me it is nearly 10 dB. for a 1.2m dish it should be more than 4 dB, for Simon perhaps 6 dB.

Mike,

I see 5 to 6dB. I can’t put 18v into my LNB for vertical polarisation, that’ll be the main problem.

I can probably squeeze 1 dB more out of my system, I may do that if I ever have time.

What’s the NF for a LNB? I’m using the Single Opticum LSP-02G.

I can receive my own DATV signals sent with under 1 watt. I have a 2.4m dish, That is equivalent to 4W for a 1.2m dish so Simon will have enough EIRP. On receive the difference between a 2.4m and 1.2m dish is under a dB. This is because you are receiving the transponder noise floor and the link limited by the SNR on the uplink. A 30m dish would only be a dB better. Diminishing returns. Simon's dish is in between these so should be getting around 11 dB MER on the DATV beacon. There are various reasons this might not happen, dosh pointing and focus being two but phase noise being a third. Knowing what he has I would think the dish might not be totally optimised. It is easy to tell, measure the noise floor of the narrow band transponder relative to the band just below, there should be an uplift. for me it is nearly 10 dB. for a 1.2m dish it should be more than 4 dB, for Simon perhaps 6 dB.

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Mike,

I see 5 to 6dB. I can’t put 18v into my LNB for vertical polarisation, that’ll be the main problem.

I can probably squeeze 1 dB more out of my system, I may do that if I ever have time.

What’s the NF for a LNB? I’m using the Single Opticum LSP-02G.

I can receive my own DATV signals sent with under 1 watt. I have a 2.4m dish, That is equivalent to 4W for a 1.2m dish so Simon will have enough EIRP. On receive the difference between a 2.4m and 1.2m dish is under a dB. This is because you are receiving the transponder noise floor and the link limited by the SNR on the uplink. A 30m dish would only be a dB better. Diminishing returns. Simon's dish is in between these so should be getting around 11 dB MER on the DATV beacon. There are various reasons this might not happen, dosh pointing and focus being two but phase noise being a third. Knowing what he has I would think the dish might not be totally optimised. It is easy to tell, measure the noise floor of the narrow band transponder relative to the band just below, there should be an uplift. for me it is nearly 10 dB. for a 1.2m dish it should be more than 4 dB, for Simon perhaps 6 dB.

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Hi Simon,

forget those BS numbers of 0.1dB noise figure for LNBs.

If you just look up the NF of the transistors used in the LNBs they are typically above 0.5dB at 11GHz.

I would guess your LNB has a noise figure of about 0.8dB or worse.

Which is still a good number for a PLL based low noise downconverter which costs less than 10 Euros.

Kind regards

Matthias

www.dd1us.de

Ah,

My LNB has a NF of 0.1dB (sceptical).

Mike,

I see 5 to 6dB. I can’t put 18v into my LNB for vertical polarisation, that’ll be the main problem.

I can probably squeeze 1 dB more out of my system, I may do that if I ever have time.

What’s the NF for a LNB? I’m using the Single Opticum LSP-02G.

I can receive my own DATV signals sent with under 1 watt. I have a 2.4m dish, That is equivalent to 4W for a 1.2m dish so Simon will have enough EIRP. On receive the difference between a 2.4m and 1.2m dish is under a dB. This is because you are receiving the transponder noise floor and the link limited by the SNR on the uplink. A 30m dish would only be a dB better. Diminishing returns. Simon's dish is in between these so should be getting around 11 dB MER on the DATV beacon. There are various reasons this might not happen, dosh pointing and focus being two but phase noise being a third. Knowing what he has I would think the dish might not be totally optimised. It is easy to tell, measure the noise floor of the narrow band transponder relative to the band just below, there should be an uplift. for me it is nearly 10 dB. for a 1.2m dish it should be more than 4 dB, for Simon perhaps 6 dB.

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