dish tuning tips wanted

[Mark in Portugal]

Hi all;
I've just got my new 1.8 meter primary focus dish bolted to the roof.

I've lined it up using a handheld GPS [marked a point 150 meters away, lined it by sight] and my adjustable builder's level.

Tomorrow I'll connect it to my receiver [vu+ duo] and attempt to fine tune it.

LNB is invacom quad.

This is my first time, so please be gentle...

I have a cheapo analogue signal meter; I happen to have an oscilloscope. Does anyone know if that can be used?

I don't have a portable TV I can use for tuning, or a helper to shout at me from the TV in the living room.

The LNB and feed horn can be moved in and out, skew should be 27 degrees. The rings of the feedhorn can be screwed in or out a bit on the mount tube; is that an adjustment or just some extra thread left on the tube?

Is there a "best order" to make the adjustments in?

Photos to follow.

 

[satelliteman]

I think you may struggle without a decent meter. A dish of this size will need small adjustments.

 

[Huevos]

You can't do anything with the oscilloscope. What I do is set up the elevation with a digital level and then swing the dish east/west until the spectrum shows the correct satellite fingerprint. Then just fine adjust. The Duo is not going to be much help until you are already well enough aligned to be able to lock the signal. Start with an easy transponder like Sky News (12207 V 27500 2/3). If you have a Duo and a laptop streaming to the laptop negates the need for a helper.

 

[Mark in Portugal]

Thanks Huevos;
I used the plugin "openwebif". It took me a while to figure out how to access it from my pc.
For anyone else who needs to know, you have to put into the address bar of your browser; ip address, 192.168.1.xx:0000 where 0000 is the port the plugin is set to, and of course the ip address is the ip address of the receiver. I found it in my router settings.

I set the dish with basic navigation and then a cheapo analogue meter first, then used the openwebif screenshot function to monitor the "sat finder" function in Vix over my laptop while I was up on the roof to get the signal to noise ratio optimized; mainly by adjusting the skew.

Later in the evening I saw that the snr had degraded a lot, down to 65% or so. But since I have don't have a CAM yet, I don't know if it's bad enough to affect the picture. I'll try to get up there tonight and see if I can improve it.

 

[Huevos]

Later in the evening I saw that the snr had degraded a lot, down to 65% or so. But since I have don't have a CAM yet, I don't know if it's bad enough to affect the picture. I'll try to get up there tonight and see if I can improve it.

You've lost me there. BBC/ITV are not encrypted, so what do you need a CAM for?

Astra 2D signals get pixeling from about 40% SNR, and collapse completely around 36%, so 65% is more than enough. At the strongest point in the day I get around 60% SNR from BBC1 HD, that channel works flawlessly 24/7, so 65% is plenty.

 

[Mark in Portugal]

That's odd; I show a strong signal, a partial channel list, but no reception. I assumed there must be encryption; I checked on the "freesat" site and it said you need their receiver box and an internet connection...

Any idea what I'm doing wrong?

 

[Huevos]

Maybe you are on the wrong satellite? What transponder did you use for alignment? Have you done a channel scan? What did you find?

 

[Mark in Portugal]

I don't know what I did, but while mucking about earlier I deleted the channel list.

Now I just re-scanned [automatic], and I have free to air channels working.

I can't check how many, since my other half has been culturally deprived for so long, she won't let me switch away from QI.

Thanks again!

 

[Channel Hopper]

I can't check how many, since my other half has been culturally deprived for so long, she won't let me switch away from QI.

Get rid, the programme isn't cultural. It's profitable for the makers even in it's current incarnation.

 

[Mark in Portugal]

If the makers get profit from it, all the better as far as I'm concerned...

Try having Portuguese TV for a couple of years, and you'll know what I mean by cultural. It's tough out here in potato country!

I think I know what I did wrong before; the tuner settings had disq enabled, but the 2 tuners are each wired directly to their own connection on the LNB.

I think that changing disq b to 'disabled' allowed the box to search properly.

Or maybe it was because I enabled CCcam? No added lines or anything...

Anyway, it's working.

 

[Huevos]

Or maybe it was because I enabled CCcam?

Doesn't make any difference on FTA channels.