4ft Ku dish or 6ft prime focus for Ku?

[Sadie]

I've been procrastinating about which dish to buy to replace my 1m dish so I can pull in all the PBS DVB S2 signals on Ku.
It came down to Fortec Star FC120CM a 1.2m Ku offset dish or a 6ft C/Ku prime focus dish, the local dealer only has the cheaper Digiwave and Fortec brand dishes and an appropriate Lnb the BSC 621 is available. This would give be the added advantage of being able to play around with C band although it's not the main priority.
Looking at the specs the 6ft dish should offer a clear 2dB advantage on Ku, so I decided to go that route. When I told the local dealer what I was planning to do he insists it won't work and I should go for the FC120CM. He would make a lot more money selling me the bigger dish so he obviously has my best interest at heart, is he right?
Reading a few threads on this forum it appears these 6 panel C/ku dishes and Lnb can be a bit tricky to set up perfectly on Ku, has any body had success at setting one of these up on Ku to give superior performance than the 1.2m ku dish I'm looking at?

 

[brentb636]

I'm leery of using a combo Ku/Cband lnbf on a 6 foot Prime Focus dish, and expecting REALLY GOOD Ku results. I'm more inclined to using a 1.2M offset dish for Ku and a seperate 6 foot dish for C-band.
Like most things in this hobby, your combination Ku/Cband results will be much better with a much larger dish. The positioning of an HH motor , in my experience, is also better for the hard to acquire Ku signal, and more repeatable ( unless of course, your motor has a lot of "slop" in it).
I'm sure you'll hear other opinions, too.

 

[TRG]

If it were me, and I decided to go with the six foot dish for the extra gain I wouldn't use a C/Ku LNB either. I'd go with a Ku only LNB thats designed specifically for a prime focus dish. Like this one; Satellite AV - Free to Air Satellite Equipment Distributors - GEOSATpro, Glorystar 888-483-4673

That said, I would imagine that the 1.2 meter offset would be more than sufficient. Thats what I plan on using if my 90 cm dish wont collect enough signal on 125W for the PBS S2 signals. I get my Sathawk from Sadoun next week so I'll find out soon.

I get a pretty strong signal on AMC 21 here in New Mexico so the 1.2 meter dish should be more than enough for my application. You situation may be different depending on how the signal pattern reaches your Northeast location.

Let us know what you wind up with. And as always, pictures are welcome.

 

[Mr Tony]

TRG has the best option if you go with a 6 footer. Get that prime focus LNB. I have one on my 6 footer and it works GREAT for those really weak signals. The only drawback is when aiming you have a small window to get a great signal. Its not as easy as aiming a 36" dish at that sat. I used this setup a couple weeks ago to get a college football game that my 36" couldnt even get a sniff of. The 6 footer had a 60 quality signal (threshold was 30)

If you want PBS 24/7 and the dish is fixed, the 1.2m is more than sufficient. I tried it here in MN when LPB first started out and couldnt lock it at night...the 1.2m locked it strong all day and night

 

[trommy]

Hi Sadie.You should be able to pull 125w in easily with that 1M dish.Look at my signature.I'm up near Amherst now but I got the same results in the HRM.I'm going out now to retire a couple or 3 trees now so I can re-aquire 83w with a 26x36 sc dish.They have the screw on the back for elevation so you can get it spot on.C band is the way to go though as I am in the slow lane in that direction right now also.G'luck

 

[Sadie]

Thanks for the replies, good idea to go with just a Ku Lnb, I'm still procrastinating although I'm leaning towards the 4ft ku dish because in theory it should work and its a lot cheaper.
According to the Lyngsat footprint map I'm sitting right on the 48dBW line so allowing an extra couple of db for the S2 signal and maybe an extra couple of dB due to weaker transponders I should still have a bit of margin with the 4ft dish

trommy, thanks its always great to get reports from some one in the area, are you getting the DVB S2 signals? I don't have any problems with the regular DVB signals most are at 100%Q on 125W. My dish may not be in optimum condition it was found in a garbage pile a few years back although its been doing great until the S2 signals came along, at this point I would be real glad to confirm it isn't performing up to potential, it would make selecting a replacement easier.

 

[cracklincrotch]

I'm in Halifax and use a one meter round Star Choice dish for the PBS feeds. No problem getting Louisiana PBS, as well.

Except when it's raining pretty hard or snows.

 

[trommy]

Hi Gang.I just 'retired 5 trees but they are only leaning on other trees.Nevertheless,I managed to re-aquire 83w with high60's Q on a 26x36 sc dish and it's not peaked,too dark and too cold.Black Sheep is on now.
Sadie,you could look around for one of these dishes not in use and ask if you can have it.I can give you one.I should be in HRM in the next week or 2 if that's anywhere near you.Let me know.As for S2,I don't have any STB's that do S2.I'm thinking of Azbox when I get C band.

 

[Sadie]

Hi cracklincrotch good to hear from you again, I've been wondering if you were still getting Louisiana PBS, for me its unreliable only coming in under perfect conditions and I've spent a lot of time tweaking the dish. I feel a bit more confident getting the 4ft dish and having a bit of a margin.

trommy thanks for the generous offer, right now I'm eager to play with a bigger dish and the extra margin for S2 will be nice. I don't know if the is a cure for that bigger dish disease once you acquire it.

 

[cracklincrotch]

Hi cracklincrotch good to hear from you again, I've been wondering if you were still getting Louisiana PBS, for me its unreliable only coming in under perfect conditions and I've spent a lot of time tweaking the dish. I feel a bit more confident getting the 4ft dish and having a bit of a margin.

I'm sure the 4 footer will work for you.

The odd thing is the 1 meter I use is on a misaligned motor and I get LPBS at about 55-60% on it. It's the only sat that the motor will hit. But I don't want to fool with this as PBS is the only thing I need the dish for.

I couldn't ever find LPBS when I tried looking for it. It just kinda showed up when I was flipping through transponders. Go figure.

 

[Sadie]

The odd thing is the 1 meter I use is on a misaligned motor and I get LPBS at about 55-60% on it. It's the only sat that the motor will hit. But I don't want to fool with this as PBS is the only thing I need the dish for.

I couldn't ever find LPBS when I tried looking for it. It just kinda showed up when I was flipping through transponders. Go figure.

Any luck with the DVB S2 signals from OETA and Montana PBS ?

 

[Wescopc]

One thing to remember with a prime focus dish - LNBs with dual output are not readily available for use with more then one receiver.

Invacom makes a flange mount line with multi-outputs (**F-031), utilizing the universal KU frequencies for prime focus. Using a universal LNB would limit your choice of switches for multi-dish setups.

What I am saying is you have more flexibility using a Standard KU LNBF with an offset dish then you would using a Universal KU LNB with a prime focus dish.
Bob

 

[Beano_face]

I've been procrastinating about which dish to buy to replace my 1m dish so I can pull in all the PBS DVB S2 signals on Ku.
It came down to Fortec Star FC120CM a 1.2m Ku offset dish or a 6ft C/Ku prime focus dish, the local dealer only has the cheaper Digiwave and Fortec brand dishes and an appropriate Lnb the BSC 621 is available. This would give be the added advantage of being able to play around with C band although it's not the main priority.
Looking at the specs the 6ft dish should offer a clear 2dB advantage on Ku, so I decided to go that route. When I told the local dealer what I was planning to do he insists it won't work and I should go for the FC120CM. He would make a lot more money selling me the bigger dish so he obviously has my best interest at heart, is he right?
Reading a few threads on this forum it appears these 6 panel C/ku dishes and Lnb can be a bit tricky to set up perfectly on Ku, has any body had success at setting one of these up on Ku to give superior performance than the 1.2m ku dish I'm looking at?

im sure a bigger dish will help you...

but I dont have a problem with those dvb-s2 signals on 125, with a 36x 39" dish... and I'm up north, in Canada.

not sure where you are located..?. your 1 meter should be able to pull them in. what kind of lnbf do you have?

 

[Sadie]

not sure where you are located..?. your 1 meter should be able to pull them in. what kind of lnbf do you have

I am in the south part of Nova Scotia, I should have at least the same signal as most of Canada but it's in an area where the signal starts to drop of rapidly if the map is a little bit out I could have a significantly weaker signal, that said cracklincrotch is only a few hundred Km from me and he has a good signal so I doubt if it's an issue.

The LNB on the other hand probably is, this summer I had a lighting strike that took out the good LNB a cable and the switch for some reason the motor was OK apart from losing its memory and the prof 7301 card somehow survived. Right now I'm running an old StarChoice LNB that probably isn't as good although after replacing the fried bits the signal levels all appeared to be back to normal.

Another possible issue is the cable length, over 250ft of RG6, earlier tests with a weak DVB signal with a receiver at the dish and then at the end of the cable showed that although the was a drop in signal level the quality remained unchanged. I'm reluctant to try a line amplifier as I found they are often noise generators but as a last resort I might cut the cable and try one in the middle.

If all goes according to plan I'm going to pick up a new Ku 4ft dish and LNB on Friday, I just planted a new pole for the dish this afternoon but the forecast is for rain for the weekend, o well at least the cement will have time to cure.

 

[Sadie]

The new Fortec Star FC120CM 4ft dish is installed and tweaked on 125W, it didn't come with a LNB holder apparently it takes a LNB that bolts directly into the arm so I had to cobble something together. The Sg2100 motor doesn't seem to have any trouble turning the dish, what the increased wind load does to the gears remains to be seen.

The good news, I'm now pulling in all the PBS DVB S2 signals most of the time

I never saw OETA on the old 1 meter dish, now its the best signal Q100 most of the time.

Montana PBS is Q50 most of the time occasionally it goes as high as Q80

With both of these signals the threshold is Q15 which is odd because with a regular DVB signal the threshold is Q33.

LPS is an odd signal in that the threshold is Q80 its the first signal to go as conditions deteriorate.

We have had a good mix of conditions from perfect clear skies to really heavy rain as conditions deteriorate first LPS goes followed by Montana and OETA although OETA hangs in really well almost as well as the DVB signals which I never lost.
On other satellites except for 103W with its funny skew just about every signals hits Q100 which is nice, nothing like a bigger dish.

I was unable to get the LNB I wanted an xtreme 2 so I ended up getting stuck with a Digiwave LNB of dubious quality, I've got a couple of LNBs on order hopefully one will provide me with a bit more of a margin.