Setting up an Es'Hailsat2 reception station
Posted: Sat Feb 16, 2019 10:26 am
Having spent much of the last two days up and down the ladder to the garage roof where my dish is located, I thought I would share a few observations about Es'hailsat2 reception and present a question for discussion.
The easiest way to line up the dish is to get a Satlink handheld receiver tuned to BBC Arabic, Badr4, 26East, 11996MHz, horizontal, 27.5ms/s, DVB-S, FEC3/4. Having optimised the dish on this, I could get no further improvement when tuned to the beacon.
It is worthwhile spending time to get the last 1% signal quality on BBC Arabic because this will help to improve your MER on the weaker through signals. This is very frustrating because with the fairly crude clamps that domestic dishes have, final tightening of the bolts often pulls it off heading. Slide the LNB up and down the clamp to get the feedhorn in the dish focus and turn the LNB slightly clockwise from vertical to optimise the skew angle.
If you have a dual output LNB, try both ports to see which is best. On my Octagon twin, one port is 1dB above the other.
Avoid the cheap satellite cable often sold at the DIY sheds today, especially for the port you are using for TV. You will know the cheap type because the centre conductor is just copper plated, not solid copper, the foil is metalised plastic and the braid very thin. Changing to Labgear branded, all copper construction cable gained me 1-2dB.
There has been much discussion about the stability of the LNB local oscillater and injecting an external reference to improve this. I have found that if you let the Octagon PLL type warm up for a short period, it is quite adequate for SSB voice reception on the narrowband transponder. A DRO type is hopeless.
Don't panic if you see the beacon MER drop drop by 3dB! Check to see what other traffic is on. When someone sends a 2ms/s signal at a similar level to the beacon, its MER will drop about 3dB.
By careful attention to all these details, I have got beacon reception up to 10dB MER on a fairly modest oval offset dish 97x87cm.
Finally, a question for discussion! Many of us have used Minitioune from its inception and have learnt that it does not like other strong signals near to where it is tuned. To what extent is a 2ms/s beacon, 10dB above the noise, preventing reception of the weaker through signals? Will we have a beacon off period to measure if this is a valid concern?
Happy watching! Shaun G8VPG.
The easiest way to line up the dish is to get a Satlink handheld receiver tuned to BBC Arabic, Badr4, 26East, 11996MHz, horizontal, 27.5ms/s, DVB-S, FEC3/4. Having optimised the dish on this, I could get no further improvement when tuned to the beacon.
It is worthwhile spending time to get the last 1% signal quality on BBC Arabic because this will help to improve your MER on the weaker through signals. This is very frustrating because with the fairly crude clamps that domestic dishes have, final tightening of the bolts often pulls it off heading. Slide the LNB up and down the clamp to get the feedhorn in the dish focus and turn the LNB slightly clockwise from vertical to optimise the skew angle.
If you have a dual output LNB, try both ports to see which is best. On my Octagon twin, one port is 1dB above the other.
Avoid the cheap satellite cable often sold at the DIY sheds today, especially for the port you are using for TV. You will know the cheap type because the centre conductor is just copper plated, not solid copper, the foil is metalised plastic and the braid very thin. Changing to Labgear branded, all copper construction cable gained me 1-2dB.
There has been much discussion about the stability of the LNB local oscillater and injecting an external reference to improve this. I have found that if you let the Octagon PLL type warm up for a short period, it is quite adequate for SSB voice reception on the narrowband transponder. A DRO type is hopeless.
Don't panic if you see the beacon MER drop drop by 3dB! Check to see what other traffic is on. When someone sends a 2ms/s signal at a similar level to the beacon, its MER will drop about 3dB.
By careful attention to all these details, I have got beacon reception up to 10dB MER on a fairly modest oval offset dish 97x87cm.
Finally, a question for discussion! Many of us have used Minitioune from its inception and have learnt that it does not like other strong signals near to where it is tuned. To what extent is a 2ms/s beacon, 10dB above the noise, preventing reception of the weaker through signals? Will we have a beacon off period to measure if this is a valid concern?
Happy watching! Shaun G8VPG.
