Fibo 90 feedhorn and fixed Az/El mount

[Captain Jack]

Another update. Disappointed with performance, I strung the dish again and again, it was slightly out. Pulled the sides of the dish until the strings came together (in situ) and saw the signal on Badr-4 jump from 5.8dB to 7.4dB!

Strangely, the deep eastern satellites don't seem to have much improvement - I am putting it down to alignment. With the dish warped, I must have aligned it in a compromised position. Now that the dish is straighter, I would need to realign it again... but kind losing the will to live with this now, so will leave it... for now.

 

[Captain Jack]

This thread is still in the wrong section... Mod - can you move it please somewhere more appropriate?

Right, so took advantage of the sunny morning today and thought I'd sort out the dish once and for all. It really was rubbish on some satellites that I know can be better.

First thing was to straighten the dish. The back bracket had to come off so I could bend the dish beyond where it should be. Drilled out the rivets and strung it. It wasn't too bad but could be better. Bent the dish back and forth until it was as good as it could have been. Lastly, I turned it upside down and put some books around the dish to press it down to straighten it even more.

Second was to realign the whole thing. Since I had a new digital inclinometer, thought it would be a good idea to do everything with precision. The pole was as vertical as it could be but the motor was set to something like 41 degrees when it should have been 38ish. By this time, the dish was ready to be hung back on - all strings were meeting perfectly in the middle with no gaps at all. As I didn't have any rivets or a rivet tool, I used some bolts to attach the dish back on the Y bracket. With a bit of east/west alignment, the dish was spot on and I could clearly see the signal levels were improved across the arc.

Back in the play room, I zapped to a bunch of channels and it's now really performing like it should have been to start with. MBC on 11919H on 26E was reading 8db! It never went above 6.5dB with the Penta 85. I managed to lock a couple of transponders on Astra 5B at 31.5E and am getting better signals from 12602V and 12640V on Yamal-402.

I think there's still a tiny bit of improvement to be had but for now - it's good enough!

 

[Llew]

OK CJ, Moved to more appropriate section.

 

[Captain Jack]

Replaced my home made bracket with a proper Fibo one (thanks RimaNTSS!), moved the dish up a pole a bit and realigned everything. Found that the pole wasn't quite as vertical as it should have been, so straightened that out too. Realignment was much less of a pain - used two meters! One Digisat to simply move the motor back and forth and the FS1 to measure the actual signal.

Result is a slightly increased signal across the board and especially signals from 68.5E, moved from 5-6dB to around 8-9dB, so I am happy with that.

 

[Huevos]

How far west can you get on that setup?

 

[Captain Jack]

Can lock 9e - is the furthest, then it's the wall. Not an issue since my 1.5m sees to 61w...