Wavefrontier T90 project

[Captain Jack]

There's something peculiar about those GI LNBs. They don't want to work with my FS1 meter. It thinks that it is short circuiting the connection. Works fine with receivers though. Definitely something up with the meter (maybe just need to change it up).

So couldn't test...

 

[Archive4]

My S1 does that from time to time, normally a problem with the test cable, every 2-3 weeks I make a new one and recycle the old one. ( I blame that on cheap cable )

 

[hairybadger]

Originally I had an Inverto narrow hanging off the end for 5W. I found it *very* sensitive to having raindrops on the cap, a full-width LNB was much more resistant.

 

[John]

There's something peculiar about those GI LNBs. They don't want to work with my FS1 meter. It thinks that it is short circuiting the connection. Works fine with receivers though. Definitely something up with the meter (maybe just need to change it up).

So couldn't test...

Had the same problem with some lnb's also on both my Televes sig analysers CJ ..... had to insert DC blocker in line which knocks a few dB off the sig. The worse culprits were the Ka SL3 lnb's.

 

[Lazarus]

Any progress? It has gone awfully quiet .......

 

[Captain Jack]

Sadly not. Spent the day erm....working. And putting garden furniture and the bbq grill together for the rainy season.

Stay tuned...

 

[Archive4]

What frequency is the BBQ grill on, I´ll skip the rest, rainy et al

 

[Captain Jack]

What frequency is the BBQ grill on

Probably once a year.

 

[4wd]

How accurate is this site with its skew measurements? SatLex Digital :: Technology :: Calculators :: WF Toroidal Calculator

SatLex numbers looking good, it's calculation (91° here) works in practice.

 

[satesco]

...The satellite positions I'll be setting up will be: 1w, 5e, 9/10e, 13e,16e,19e,23.5e,28e,39e and, if I can stretch to it, 42e... and maybe 5w on the other side...

Exactly this configuration I have on my WaveField dish,from 5W to 42E,to which I added 36°E,31°E,26°E,7°E,4°/5°W and 7°W,when the signal was stronger in 2008 on Nilesat,when I installed toroidal(now I don't receive anything from this position).I have chosen the center position at 19.2°E,with 16 lnbs installed on toroidal dish.

...If you include some narrow ones (Alps etc.) on the strong satellites, 3.1°E, 7.0°E, 21.6°E and maybe even 26°E can be done as well...

Indeed,with Alps I solved then the problem of the satellites which are close to each other,and I placed on 26°E/28.2° E and 9°E,7°E and 5°E with good results.

...Am I expecting too much from around the edges or is there some trick to this?

The first three steps when you adjust the toroidal are: 1.adjusting the antenna on the satellite central, 2 & 3.then at the two extremities,east and west. After you've obtained the strongest signal of these three positions,the rest of the settings is much easier.

 

[hairybadger]

Exactly this configuration I have on my WaveField dish,from 5W to 42E,to which I
(snip pictures of perfectly-wired T90)

Am most impressed by the tidiness of it all. One day I'll get around to cleaning up my installation Maybe when the good motorbike weather is over...

 

[Lazarus]

"There will be an answer, LNB, LNB"

 

[Captain Jack]

Ooookay... So, I spent most of the morning swearing at the T90 dish and how annoying it is. Swapped all the holders around so that they are now the correct way around - didn't reallly gain all much, so I went starting from scratch. Moved the centre satellite to 9e and tried getting 1w. After a lot of faffing, I managed to get over 9dB on the weaker 10714H transponder. This would be enough to lock the HD channels as well (just). Great, but then I am not able to get 39E, as it's beyond the rail line and I don't have time or materials to extend it. 5e Nordic was also coming in OK at around 8dB.

Great. But I really want 39e as well, so I put the 39e LNB as close to the edge of the bar as I could and aligned it on that. Weak-ish (11-12db), considering its power over the UK, but enough for viewing. At the other end I had 5W at 14.5dB - great. Everything should now fall into place - in theory.

Central satellite is an imaginary one at around 15e and all the satellites around that cluster, between 9e and 28e, are nice and strong.

So how did 1W and 5E fare? Not well.... I am still able to get the Nordic beam off 5E but there's little rain margin and I know it gets weaker in the evenings anyway, so I'll probably lose at least some channels then. 1W - again, most 'European' beams from there are relatively strong, but the transponder that was over 9db before is now under 8db and juuuust about locking. But not HD channels...

I might create another satellite on my receiver and add all the stronger channels on there, like Focus Sat etc. and keep the weaker ones on the 1.8m. Not sure about 5E - I only really watch the Nordic beam on there since that's where most of Viasat lives, so this will probably go on the Laminas as well.... Unless a different LNB will fare better....

 

[hairybadger]

Ooookay... So, I spent most of the morning swearing at the T90 dish and how annoying it is. Swapped all the holders around so that they are now the correct way around - didn't reallly gain all much, so I went starting from scratch. Moved the centre satellite to 9e and tried getting 1w. After a lot of faffing, I managed to get over 9dB on the weaker 10714H transponder. This would be enough to lock the HD channels as well (just).

As a matter of interest, what would you expect to get on 10714H on a "normal" eg 80cm dish? I don't know exactly where you are but are you outside the published footprint (I'm assuming you want the K1 beam - Lyngsat (yes, I know... ) lists this TP as 10716)? THOR 6 – K1 | Telenor Satellite

 

[Captain Jack]

Hm, I don't have the exact figures but Penta 85 managed the HD channels on 10934H OK in the morning but did disappear in the afternoon and the rain. It was certainly at least 2dB higher than what I am getting now. I am sure it would be OK if 1W was in the centre but around 16 degrees off it, it's probably a little much.

 

[Huevos]

Off topic: BTW you can tune the Scandinavian packages with ABM now. So scan takes seconds and channel list is ordered according to the list on the official box.

 

[4wd]

starting yet another project. Not a complex one

offtopic, here's someone who discovered the t90's great potential for non-complexity :O)
My first toroidal 90 multi dish install with 20 lnbs

 

[Captain Jack]

Interesting thread, though I am now more confused on alignment process.

This is my current understanding of the process:

1) Set dish skew to 90 degrees
2) Align the dish to central satellite by adjusting azimuth and elevation
3) Roughly set the correct skew on the dish
4) At this point I lose the central satellite. I get it back by adjusting the azimuth.
5) Now find the satellites on the extremes (5w and 39e in my case) by moving the LNB along the rail
6) Fine tune by adjusting skew of the dish and azimuth(???) until signal maxes out on both extremes. Or just skew? Or just azimuth?
7) Throw the dish in the bin

OR do I not adjust the skew of the dish at all, leaving it at 90 degrees... but then it wouldn't follow the arc, so that can't be right.

5e isn't usable - a bit of rain and it disappeared, especially now in the evening when it's weaker anyway. So that LNB will probably be going away. I am not sure I can stretch between 42e and 5w without modifications to the rail - 39e is right on the edge and 5w isn't far off it on the other side. I would like to get slightly better signal from 39e - so may need to adjust it a bit.

Maybe I am still doing something wrong but overall the dish is a bit underwhelming

The effective dish size seems to match this diagram posted by @RimaNTSS many years ago:



In theory, if I set 9e as the central satellite, 1w and 5e will come in well enough, as it will be equivalent to a 95cm-ish dish within that 20 degree range... but I lose 39e and there's not much beyond 5W until I hit 30W, which wouldn't be possible!

Argh!

Think I'll work on the LNB changer tomorrow on the Laminas...

 

[Huevos]

Step 4. Nothing should change by skewing the dish that can't be corrected by deskewing the LNB. If it requires azimuth adjustment something is wrong. Probably the central LNB is not dead central on the bar or the mast is not vertical.

 

[RimaNTSS]

What can I say CJ..... just continue to tune the dish ;). It is great dish, but asks for very precise tuning. All the angles there are very important, I mean all of them should be perfectly aligned. The nastiest ones (hard to adjust) are skew and azimuth. Somewhere i wrote step-by-step instruction for T90 alignment, when you are desperate enough I can look for that . But, in short, I would say (in order):
- central LNB placed in the middle of the rail;
- skew set-up 9use digital protractor);
- Azimuth set-up;
- Elevation set-up;
There are some similarities with motorized antenna , when you try to catch the arc.


Add: Does not matter how long you spend tuning T90, it will never be perfect