The 2.4M Fortec Star on C-Band.

Maybe not, at least for Ku anyway. Time and the weather have been against me this weekend but I've spent a couple of hours trying to peak the Ku performance today and results are pretty much as expected albeit a little disappointing. Setup on Ku is an Inverto Black Pro on an Invacom ADF120 variable feed with 35m of CT125 and I'm comparing it against a 1.2m Gibertini with Inverto Black Ultra and 7m of CT125.

The first thing to notice is the supplied FS LNB bracket and arms don't place the LNB in the centre and looking at the middle of the dish. I've had to fabricate some clamps to hold the 24mm neck of the Invacom feed but the poor construction of the arms and mount had it looking well away from the centre. Not so easy to get it set correctly on this size dish so in the end I settled on placing a 913mm length of tube in the middle of the dish and adjusting four lengths of strings to get the high end of the tube equidistant from the dish rim. Once that was done the arms and bracket were persuaded into a position that's as close as I can get it to the centre as well as aiming at the reflector centre but I doubt I've optimised it.

Performance drops the further up Ku you go although there are humps and bumps along the way so the results aren't linear when compared to the 1.2m. At the bottom end the 2.4 is about 2-2.5dB better than the 1.2 Gibby, around 11700 it's about 1.5dB better and by the time you get to 12750 performance is between the same and 0.6dB better than the Gibby. I suspect that I could improve performance at the top end by sacrificing it at the low end so maybe I could find a compromise where it's 1.5dB better than the Gibertini.

Unfortunately I don't have a second LNB to test it against the 1.8m Precision so I can't compare the two without swapping LNBs from one to the other.

As an indication of what I've received on the 2.4FS I've done all the alignment on 5W and checked 7W.
5W 11059H is 10.6dB SNR, on 7W I've gained a couple of transponders over the Gibby and 11603H is 7.2dB SNR
 
thanks for the tests and reports its performed really well in c band and not so bad in ku if we could find cheap polar mount for this dish its not a bad all rounder for the money, noticed today the dish in china sell for $20 new, so can not complain
 
$ ???

Are they like £ ????


Silly me, of course they are as of another couple of weeks time!
 
I think I might have dated her many years ago.
 
aceb said:
Maybe not, at least for Ku anyway. Time and the weather have been against me this weekend but I've spent a couple of hours trying to peak the Ku performance today and results are pretty much as expected albeit a little disappointing. Setup on Ku is an Inverto Black Pro on an Invacom ADF120 variable feed with 35m of CT125 and I'm comparing it against a 1.2m Gibertini with Inverto Black Ultra and 7m of CT125.

The first thing to notice is the supplied FS LNB bracket and arms don't place the LNB in the centre and looking at the middle of the dish. I've had to fabricate some clamps to hold the 24mm neck of the Invacom feed but the poor construction of the arms and mount had it looking well away from the centre. Not so easy to get it set correctly on this size dish so in the end I settled on placing a 913mm length of tube in the middle of the dish and adjusting four lengths of strings to get the high end of the tube equidistant from the dish rim. Once that was done the arms and bracket were persuaded into a position that's as close as I can get it to the centre as well as aiming at the reflector centre but I doubt I've optimised it.

Performance drops the further up Ku you go although there are humps and bumps along the way so the results aren't linear when compared to the 1.2m. At the bottom end the 2.4 is about 2-2.5dB better than the 1.2 Gibby, around 11700 it's about 1.5dB better and by the time you get to 12750 performance is between the same and 0.6dB better than the Gibby. I suspect that I could improve performance at the top end by sacrificing it at the low end so maybe I could find a compromise where it's 1.5dB better than the Gibertini.

Unfortunately I don't have a second LNB to test it against the 1.8m Precision so I can't compare the two without swapping LNBs from one to the other.

As an indication of what I've received on the 2.4FS I've done all the alignment on 5W and checked 7W.
5W 11059H is 10.6dB SNR, on 7W I've gained a couple of transponders over the Gibby and 11603H is 7.2dB SNR
Click to expand...

Hi - aceb -
I can understand how you feel regarding setting the l.n.b. central .....
i tried K/u on that old 3m prodelin ... which had the button hook center arm .. i had to make a semi adjustable k/u l.n.b holder ... which to be honest was not really up to the sensitivity of a 3 m dish.(the k/u sensitivity surprised me) even when i did get a good result it barely equaled my 1.8 c.m and at many frequencies it fell well short .. i spent an afternoon on it and gave up in frustration :(
 
Not sure whether to give up or have another go on a brighter, calmer day. It's not the easiest thing to get accurate either due to the rolled edges making measurements less than 100% accurate and of course at Ku even small errors can make a big difference. Once I'd got it as close as I could I was able to stand in front of the dish and just man handle the feed around to centre and repoint it and I've not seen any figures better than what I have had. Next step will be to restring it all to see if it's still in shape then attach a couple of lines across the face so I can gently warp it to see how bad the parabola is.

Frustrating for me because I was kinda hoping it would equal the 1.8 on Ku in which case it would be an easy decision to swap big dishes and also remove the 1.2. Now if anyone has a 2.4m Precision laying around gathering dust?..... :D
 
blademedia said:
thanks for the tests and reports its performed really well in c band and not so bad in ku if we could find cheap polar mount for this dish its not a bad all rounder for the money, noticed today the dish in china sell for $20 new, so can not complain
Click to expand...

I'm looking out for a polar mount that I can adapt to fit the FS as it soon gets boring having to manually move the dish then the LNB each time. If you can only put up one dish no matter what size and you want a serious dabble on C-Band then you can't go wrong with one of these, it'll beat a 1m dish on Ku so will equal what many people have for that band.

The beamwidth is much sharper than I was expecting so it's crucial to move it very gently when peaking the signal, if I get time this week I'll check both 31.5W and 36E, the former is a good test of beamwidth trying to resolve the ORTM signals on the side of Hispasat and the Sub Saharan beam on 36E will be a test of gain, normally get 12073 and 12245 on the 1.8 (just 12245 on the 1.2).

Incidentally the Jonsa website shows they do a 3.2 and 4.2m version, who's up for getting one of those over? :)
 
off topic for this dish but spotted this today didn't realise you could still buy them, wonder if they would sell motor for az/el will send email
sdsdfs.webp
 
blademedia said:
off topic for this dish but spotted this today didn't realise you could still buy them, wonder if they would sell motor for az/el will send email
View attachment 99140
Click to expand...

Looks like a reasonable clone of a Hero mount, common in the 90's for powering 4 or even 5m mesh dishes.
 
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