C-band dish size for DVB-S2/8PSK

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LocutusOfBorg

I have better things to do
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Aug 2, 2009
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Just how small of a dish will receive these signals? I recall from a couple years ago a few people stated that less than a 12 footer is too small even though I've heard that a 10 footer will work. My research indicates that DVB-S2 was developed so that smaller dishes can be used. Anyway, I'm using a KTI 12 footer that now has hail damage and is slightly out of alignment and yet it still pulls in DVB-S2/8PSK signals with no problem. It certainly doesn't have the "perfect" parabolic shape anymore. Anyway, I may have to replace my 12 footer if hail and wind damage makes it unusable in the future. If so, I don't want to have to spend $3000+ for a dish if a 10 footer or even an 8 footer will get the job done.
 
10 ft here and no problem. Get smaller and some will start to disappear. Start looking NOW for one. Have 'on hand' when replacement is deemed necessary.
 
FAT S2 8PSK muxes with average signal strength and generous FEC locks on 8 - 10' dishes very reliably. Narrow SCPC and high FEC need a quality 10'+ depending on the link budget. There really is no right answer for the required reflector size for S2. It depends on what you watch.

Never have heard that S2 was primarily developed to reduce reflector size, but rather to decrease bandwidth requirements with increased efficiency. Most S2 in NA use the higher FEC rates with increased throughput rather that use lower FEC which could allow smaller reflectors.

Go BIG or go SORRY.... LOL
 
Yes S2 and the up coming S3 when ever that gets main stream is all about different schemes to get more in less bandwidth. Nothing to do with dish size.
 
I have an 8 footer and am able to lock and view CBS feeds on 97W. That is if there isn't to much wind, the dish has to be just right. Have had cases where I couldn't get a lock some things reported, but that could of been receiver rather than antenna, as some folks with same receiver complained of the issue.

I have been happy with my 8 footer, but if you can afford it and obviously have the space (as you have a 12 footer) I would go with a 10 footer. I am sorta watching for a 10 footer, but not real hard.
 
10 ft here and no problem. Get smaller and some will start to disappear. Start looking NOW for one. Have 'on hand' when replacement is deemed necessary.

Well, the wife would have a problem with stuff like that laying around. Besides, I've looked at several dishes around here and every one has visible damage - mostly from hail. And I'm not gonna go get one that's more than a hundred miles away. So, if I need a new dish I'll have to go buy a new one. The cheapest 12' C/Ku-band dish ($650) I've found is here: http://www.ebay.com/itm/350cm-12ft-...ellite-Dish-/331615090292?hash=item4d35ccb674. But, it doesn't fit my existing 3.5" pole.
 
We have 8' and 10' dishes here and they all are able to pick up the S2/8PSK signals with no problems.
I should also say that the 8 footers are all finely tuned with a good lnb's on them.
Before upgrading the LNB's the 8 footers did not always pick up every signal the 10 footers did.

If one has access to getting a 10 footer I would pick those up over an 8 foot dish simply due to some newer HD channels that come in a bit better on a 10 foot dish.
 
I have used a 6ft dish for cband 8psk but only on easy fec like 3/4, wouldn't work for anything else. I'd say a 10ft is really min for reliable reception. There was a lot of boy as strong 3/4 I couldn't receive. Bigger is always better

UDL
 
Currently a well tuned 10' er will pull about anything out of the sky. My 7.5' locks plenty of dvb s2 apsk.
My 2 10' Sami dishes lock about everything with norsat pll lnbs.
 
I've got City TV and SLN on my 90cm dish before and they are DVB-S2 8PSK. They do have a 1/2 FEC though. Trying to get a high FEC signal that is DVB-S2 8PSK on a tiny dish just won't work.
 
I have been experimenting for the last 20 years with dishes from 4 to 10 feet, LNBs, and receivers.
Some things to note when trying to receive DVB S2/8PSK:
1. The satellite footprint for your area and the signal strength. Intelsats have a weaker signal strength for US. Locations.
2. The polarity of the satellite transponder. Satellites with circular reception require a dedicated LNB for reception. I have used a 6ft dish with a DMX 741U combo C/KU with Teflon insert to get 40.5W that consisted off all circular polarities and could not get any S2. I switched over to a Chaparral LNB and was able to get all S2 using the same size dish. Hence it is not just a matter of dish size but you can use a smaller dish with a higher quality LNB.
3. Receiver sensitivity. Some receivers I used like Satcruiser, AZBOX, Amiko A3 have a sensitive tuner with minimal heating to the S2 Tuner card and allow stable reception with a smaller dish.
4. Alignment of your system, motorized or non motorized. Obviously a larger dish is more forgiving with a signal than a smaller dish

So what I found out that using a 6 footer, high quality LNB, and a sensitive receiver I was able to get 98% S2, 8PSK. From roughly 22W to 136W. Newer receivers contributed enormously with faster processors and better bugless freezing.
Smaller than 6 feet was "hit or miss".
An 8 footer would be better if your LNB/receiver was not cutting edge
 
4. Alignment of your system, motorized or non motorized. Obviously a larger dish is more forgiving with a signal than a smaller dish

I've had a lot of trouble with my 12 footers not staying on target. So, saying that a larger dish is more forgiving isn't necessarily true. There isn't a loose nut or bolt on my dishes either. As a matter of fact, I've stripped some nuts and bolts. I'm mentioning this since there will be someone that'll say I have a loose nut or bolt somewhere. Anyway, I'm having trouble staying on target with my KTI 12 footer. I'd get it peaked and save the position only to have to re-peak again the after moving to another bird and then back. When I used my 4DTV receiver as a dish mover, I was able to use it's autopeak feature to get back on the bird whereas with an FTA receiver I don't have that easier solution. I was hoping to make the FTA system easier to use mostly for the wife but if I can't keep the dish reliably on the target then I'm the one that has to mess with it to get it working again. As much "fun" as it has been I'm just about ready to send everything to the scrap yard. I'm retired now and have more time to play with this stuff but the frustration level has gotten quite high.
 
Noise in the pulse counter wiring would be my first guess? Please describe the wiring to the actuator, what type of actuator, wire gauges, shielding, grounding etc... I'm sure there are smarter ones than me here that can also help get to the bottom of this situation. Electrical noise would make some counts get lost on the way back to the position you are going for, then the dish would be in wrong spot. Motor and sensor wires in the same bundle is the cause I have seen here mostly.
 
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