Chicken & Egg on New Installation

[EA7KIR]

It's a new installation, so I paid a satellite installation engineer to align the dish to QO-100 for me. So I'm in a chicken & egg situation. Is it the dish, is it something I'm not understanding?

I'm trying to receive QO-100 Beacon using Longmynd with a Bullseye LNB fed using the 12 volts from the NIM on a BATC Minitiouner V2 PCB.

I figured 10491500 kHz - 9750000 kHz = 741500 kHz, so I start Longmynd as follows, but it's not receiving.

longmynd -i 192.168.1.33 7777 741500 1500

Longmynd and fake_read are outputting status. Am I doing something wrong? Could it be...

1) The LNB is not pointing at the satellite or the polarisation is incorrect?
2) I'm calculating the request frequency incorrectly?

I would not expect a TS at this stage, but the IP address I'm giving is that of my iMac running VLC. The host name of the Raspberry Pi is satreceiver.local and the IP address of my iMac is 192.168.1.33.

3) Perhaps the IP Address is supposed to be an address on the Raspberry Pi?
4) Is udp://satreceiver.local or udp://satreceiver.local:7777 the endpoint I'm supposed to point VLC to?

Anyway, here's the Longmynd outputs I'm currently getting. It repeats forever...

Flow: main
Status: Main Frequency=741500 KHz
Main Symbol Rate=1500 KSymbols/s
Using First Minitiouner detected on USB
Main TS output to IP=192.168.1.33:7777
Main Status output to FIFO=longmynd_main_status
Main refers to TOP F-Type
TS Timeout Period =5000 milliseconds
Status: opened fifo ok
Flow: FTDI init
Flow: FTDI USB init
Flow: FTDI set mpsse mode
Flow: FTDI USB init
Flow: FTDI set mpsse mode
Flow: FTDI setup io
Status: MPSSE Synched AA FA
Flow: FTDI nim reset
Flow: FTDI GPIO Write: pin 0 -> value 0
Flow: FTDI GPIO Write: pin 0 -> value 1
Flow: UDP Init
Flow: NIM init
Flow: STV0910 init
Flow: stv0910 init regs
Status: STV0910 MID = 0x51, DID = 0x20
Flow: STV0910 set MCLK
Flow: Setup equlaizers 1
Flow: Setup carrier loop 1
Flow: Setup timing loop 1
Flow: Tuner init
Flow: Tuner cal lowpass
Flow: Tuner set freq
Flow: Tuner set freq
Status: tuner:0, f_vco=0x2d41f0, icp=0x2, f=0x2eeee, n=0xc5,
rdiv=0x1, p=0x1, freq=741500, cfhf=2331
Flow: LNA init 1
Status: found new NIM with LNAs
Flow: LNA init 2
Status: found new NIM with LNAs
Flow: FTDI GPIO Write: pin 4 -> value 0
Flow: STV0910 start scan
Flow: No-data timeout, re-init config.
Flow: Config cycle: Frequency [0] = 741500 KHz, Symbol Rate [0] = 1500 KSymbols/s
Flow: NIM init
Flow: STV0910 init
Flow: stv0910 init regs
Status: STV0910 MID = 0x51, DID = 0x20
Flow: STV0910 set MCLK
Flow: Setup equlaizers 1
Flow: Setup carrier loop 1
Flow: Setup timing loop 1
Flow: Tuner init
Flow: Tuner cal lowpass
Flow: Tuner set freq
Flow: Tuner set freq
Status: tuner:0, f_vco=0x2d41f0, icp=0x2, f=0x2eeee, n=0xc5,
rdiv=0x1, p=0x1, freq=741500, cfhf=2331
Flow: LNA init 1
Status: found new NIM with LNAs
Flow: LNA init 2
Status: found new NIM with LNAs
Flow: FTDI GPIO Write: pin 4 -> value 0
Flow: STV0910 start scan

Please help.

[g8gtz]

Hi Michael,

If the LNB is set in the normal position (cables coming out towards the ground) you will need 18v on the LNB supply. Alternatively, twist it through 90 degrees and feed it with 12v.

If still nothing then check if can you receive the narrowband beacons? These are much easier to receive than the DATV beacon and will tell you if the dish and LNB are OK. (You will need 12v on the LNB to receive the NB section).

73
Noel

[EA7KIR]

twist it through 90 degrees and feed it with 12v.

Thanks Noel. I'll give a go, but I did tell the man to use 12 volts.

[g0mjw]

The 12/18V supply controls the polarisation, Narrow Band transponder is 12V, the Wide Band transponder 18V. That's probably your problem.

Mike

[EA7KIR]

Clinging on to a ladder in the Mediterranean midday sun is proving too much. However, I've managed to establish that 12 volts are arriving at the LNB, so that's relief! I'll rotate the LNB when the sun moves away.

Meanwhile, can anyone tell me which direction a -34.1 degree skew is? Is it clockwise or anticlockwise as I face the dish with the satellite behind me?

[g0mjw]

Imagine you are behind the dish looking at the geostationary arc up in the sky. If you imagine a satellite on the arc, vertical polarisation will be a plane going through the centre of the earth. When the satellite is due south of you, that plane will be locally vertical. When the satellite is to the east, that plane will appear tilted counter clockwise. Similarly for a satellite to the west it will be tilted clockwise.

As you are in Spain the satellite is to the east to the skew is counter clockwise, when viewed from behind the dish. If you are looking at the dish from the front, with the satellite behind you, which is the normal place to be when adjusting, it will be reversed so turn it clockwise from your point of view.


34.1 degrees on the med puts you in Málaga

Mike

[EA7KIR]

a plane going through the centre of the earth

Thanks Mike, but I find it hard to imagine a plane going through the centre of the earth.

Currently, with my back to the satellite, the skew is clockwise.

Is this correct for 12v direct from the NIM, or do I need to rotate it 90 degrees? I don't have an 18v supply.

[g0mjw]

You need to rotate by 90 degrees to make H V and V H. That way it will work off 12V

Mike

[EA7KIR]

A cloud came by, so here it is on a 1.3m dish - rotated 90 degrees from the original position. It might not be exactly -34.1, but I think its close.

It still isn't receiving the beacon, so am I starting longmynd with the correct offset for a Bullseye LNB?

longmynd -i 192.168.1.33 7777 741500 1500

IMG_2633.jpeg (662.36 KiB) Viewed 3503 times

[G8GKQ]

Michael

I suggest that you look for the narrow band beacons first, and then peak the dish pointing on those. Then rotate the LNB to null out the narrow-band beacons and you are all set to receive DATV.

I NEVER start by looking for the WB signals. The narrow band ones are so much stronger and easier to align on.

Dave