What size dish to reliably receive S2 signals for both C-Band and Ku-Band?

[linuxman]

I haven't posted in a while, but wanted to talk about some discoveries I have made recently. Even though I haven't written much in a while, I still do read a lot of what others have written especially about this question.

I also have a unique situation where I have several different size and types of C-Band dishes, as well as several size and types of Ku Band dishes all hooked into multi-switches, 4 port diseqc switches, and then into 8 port diseqc switches. I am also using a variety of Orthomode feeds, Geosat Pro C2 LNBFs, and Geosat Pro SL-2 LNBFs.

I have been a little relaxed in scanning for new signals because I have just been laid back enjoying my setup as is.

The other evening I saw where someone had posted a new S2 signal on Galaxy 17 at 91W, so I thought it would be an excellent trial to see if I could get it on my Birdview perforated dish which measures 8 foot 3 inches across the face. That dish has a dual Chaparral Orthomode feed on it, and I thought that might be an excellent place to try a "under" sized dish to see if it would come in or not. So I did a blind scan with my Openbox S9 receiver and the signal popped in without difficulty.

I thought the rule of thumb was that a 10 foot dish was needed to get S2 signals reliably.

Last night I had read where there was another S2 signal on AMC1 at 103W, so I tried that on my Birdview solid dish which measures 8 foot 6 inches across the face, but that dish has a Geosat Pro C2 LNBF on it.

Same thing. The signal popped in with no difficulty at all.

These dishes are all fixed dishes and what I mean by that is that I cannot bump them from side to side to get a better signal. They are set in that position unless I manually hook up something at the dish to move them and have been that way since I set them up several months ago.

I get Montana PBS on my Prodelin 6 foot Ku dish using a Gesoat Pro Sl-2 LNBF but the satellite is 4 degrees off center on that dish, but the size of the dish prohibits my having anything special about that.

I did read where a member here in the past couple of days was getting Montana PBS on a Super Dish which defeats all acceptable wisdom for getting S2 reliably on Ku dishes.

To be honest, I get Montana PBS fine, but have never been able to figure out why that channel stutters every few seconds since they switched to S2 and don't know whether others are still having this problem.

Also the channel I am getting on G17 stutters every few seconds as well. I have good signal quality, and can see no reason for the stuttering but it is there. That may be a side discussion for a different thread.

So with the above and other discussion about receiving S2 signals, we are back to the original question.

What size dish is needed to reliably receive S2 signals for both C-Band and Ku-Band signals?

 

[Blindowl1234]

Linuxman, I had a six footer and for me it wasn't cutting it. It got most stuff but not all. I upgraded to an 8 foot and now get 99% of whats there. The weaker TP on the RTN channels- 87west is still not locking most days with my 8 foot. I'd say to anyone.. 36" for KU and 8 foot or bigger for Cband. I started with smaller dishes and ended up upgrading both KU and Cband dishes. Montana PBS for me isn't all that reliable on the 36" which is an old Primestar I motorized. Another example speaking of PBS is with the 30" I had difficulty getting LPB and OETA PBS. The 36" brings them in fine....just my 2 cents worth....Blind

 

[Diamond Jim]

Hi Fred, long time no hear. I have been told at least a 10 footer to do it good and I've been to a 8 footer will get by. I was gonna get one of those AZ Boxes, but I'm not spending that kind money when there is a big chance that it will be bascially useless.

 

[Mr Tony]

It depends on the FEC of the signal and how much time you want to spend tweaking

1/2, 3/4 and 3/5 FEC on the 6 footer...no issues
5/6 (which is what the RTV ones are on 87W)....I have to spend a lot of time tweaking to maximize signal
7/8, 8/9, 9/10...no way

I would hazard a guess and say 8 foot minimum for reliable reception. Yes you can get stuff with a 6 footer but its like trying to get a KU feed on a 18" dish.....you might kill an hour and get it to work...only to be disappointed in the end

 

[Cadsulfide]

I have a 3' DTN dish parked @ 125W Ku and sometimes Montana stutters, but the LPB feeds are always rock solid

 

[pendragon]

1.8m + single ortho + Norsat 8115s + Prof tuners = pretty much all S2, including 9/10 FECs.

Same with dual-ortho = loses a couple of S2 9/10 FECs.

Same with 2.3m and single ortho = everything.

3.0 - 3.2m = saved mostly for very low elevation (< 10 degrees) and out-of-footprint work.

90cm + bandstacked Superdish LNB with DP feed mod = all S2, except in fairly nasty weather.

1.2m + Invacom dual polar LNBF = all but in a torrential downpour.

1.8m solid offset + Invacom universal LNB + custom feed = anything, anytime.

It's true everything has been carefully tweaked and signal levels and equalizations have been optimized so the CNRs at the dish are within about 0.1 dB at the receiver jacks in the house.

All things being equal, a bigger dish makes S2 reception much easier. But many LNBs/LNBFs have poor or poorly specified phase noise, rotor feeds lose a noticeable chunk of CNR and so do dual-band feeds and LNBFs. Poorly controlled signal levels and deaf receivers can also be culprits. Enough of this and even a little misalignment will easily drive the need for a much bigger dish. If one pays attention to details, S2 can easily be done on smaller dishes than many want to believe.

 

[Tron]

My 1 meter Channel Master has no trouble with the S2 on 125W. It has the factory feedhorn coupled with a Dish FSS stacked LNB (the Eagle Aspen P870). My 6 foot "PortaBUD" will get one of the two RTV transponders most of the time, albeit with rather shaky quality.

By the way, I also have occasional stuttering on Montana, although my quality is high. The stuttering is more like a pause, and does not look like breakup due to weak reception. This is on the Openbox S9.

P.S. - Nice to hear from you again, Linuxman!

 

[linuxman]

Thanks for all your replies.

So with all the collected knowledge from all of your posts, most S2 signals can be received on much smaller dishes than was previously thought, but requires much more time, expense, and effort than if using a bigger dish.

Thanks Jim and Tron. I probably won't be posting every day, but will write or respond as a topic peaks my interest.

Tron, you are absolutely correct. I should have described what was happening on Montana PBS better. It is a pause, and not a stutter. It happens every few seconds, and the same thing happens on the C-Band S2 signal I was describing as well.

Both signals are coming in fine with great signal quality levels, so it could just be the receiver and hopefully a firmware update in the future might fix it.

 

[pendragon]

So with all the collected knowledge from all of your posts, most S2 signals can be received on much smaller dishes than was previously thought, but requires much more time, expense, and effort than if using a bigger dish.

I suppose it all depends on how you look at this. In terms of time, I put the same amount of effort adjusting anything from my 76cm to 3.2m dishes. For the most part it is a one-time investment and I'm pretty efficient. That way each dish gets the maximum range of possible signals, and sometimes even on my 3.2m I need every fraction of a dB I can squeak out of it.

If I could only have two dishes, I would certainly choose at least a 3.2m for C-band and a 1.8m Prodelin for Ku. So I'm a card-carrying member of the bigger is better club, too. But not everyone has the space or the allowed/legal right to put up anything they want. My city allows me to put only two dishes in the ground, which means everything else has to go on the roof. For that and other reasons (mostly wind), putting up smaller dishes allows me to mount a lot more of them (13 on the roof + 2 on the ground) and have much better options.

It hurts me every time a newbie on the forum writes to say the biggest dish they can put up is a 1.8m, and will this be good enough to get most of what is up there, including S2. The standard response is you need a 3m, at least. I'm sure that is sufficient to drive most start-ups away. A more fair response is that if you use good parts and put the time into setting up the dish properly, a 1.8m will work fine. With a bigger dish you can use crummy parts and be lazier, but still get the same stuff.

I prefer to put high-quality parts on all my dishes, because most of the signals we capture are intended to be received on much bigger dishes than we have. As technology rolls forward, I expect we will see increased use of high FECs and probably 16PSK and 32PSK. I'm already spotting all but the latter. This will put a premium on low phase noise LNBs and low loss feeds. Those are more expensive, but not extravagantly so. A single ortho is about the lowest-loss C-band feed available to consumers and can be purchased new for around $50-60. A pair of new, low phase noise LNBs can be had for $100. These are bargains in my book.

 

[tamuin]

> A single ortho is about the lowest-loss C-band feed available to consumers and can be purchased new for around $50-60.
> A pair of new, low phase noise LNBs can be had for $100. These are bargains in my book.

Pendragon,

What are you using for your single ortho?

Thanks

 

[pendragon]

Chaparral makes a nice one. ADL's is a little more expensive, but I haven't had one of those up on a dish to compare their performance.

 

[greenterror]

I am getting all the RTV on AMC-3 with a 7.5'. I have noticed that the aim is very critical. If I move my dish east or west by a count of two on the vbox, I lose the signal. This despite have good quality on both of those TP's, about 72%. With a DVB-S signal I can usually drive the dish east / west about 5 before losing the signal.

 

[stanleyjohn]

I use a 6 footer with a c/ku 741 Lnb and get many s2 signals that are out there including RTV on AMC3.

 

[migold]

On my Azbox + GeoSatPro 90 cm + GeoSatPro 'Bullet' LNB + DG380, @ 125W I am getting LPBS2, LPBS3, LPBSHD, LPBS Feeds with S=69%, Q=49% and reception is fine. On 103W, I am getting the transponder 12117H4232 [not DVB-S2] with S=66%, Q=51% and reception is fine. However, I am not getting transponder 11880H30000 with S=70%, Q=0%. I have been thinking of increasing the Ku dish size to 1.2 meter. Do you think this will result in reception?
Thanks,

 

[hd fan]

103W is AMC 1 that has the funny skew so you are loosing signal due to the funny skew. A bigger dish will collect more but I would try tweaking the dish and lnbf aligment first to optimize signal. Also , very important, that bird is already almost 15 years old (1996) and will be replaced in this first quarter 2011 with a new bird, SES-3, launched from the Russian Baikonur using a Proton rocket so the funny skew issue will no longer play a role and you will get that signal back.

On the dish size subject , although bigger makes your life easier, for a C band dish , 8.5 ft guarantees 2 degree compliance anytime anywhere, and that is that at 2 degrees power levels are 10 dB below so you will have no adjacent interference issues. check all EIRP levels and dish recommended sizes from all sat operators in NA and you will see that 8.5 feet dish is enough if you are within the coverage area.

On Ku assuming a 70% dish efficiency a 90 cm reflector will guarantee the same 2 degree compliance at even 11.7 GHz so it should be enough if you are within the coverage area. As an example I get the 8PSK Uruguayan mux over at 30W with 5/6 on an 80 cm Ariza that keeps working under light rain and most conditions but still I would recommend 90 cm for 2 degree compliance across the arc.

This is all from the reflector point of view , then you have to collect and transmit the signal to your receiver so quality parts and attention to detail plays a big role as pendragon mentions. Few people would be able to keep C/N levels along this path within 10% of what it is at the LNB output but for most a 90 cm or an 8.5 ft dish would be enough IMO.

I have improved the (6 ft fortec star) dish , mount and LNBF aligment overtime and have noticed major improvements in receptions due to very small adjustments here and there while still using the same setup. You loose a lot due to small misaligments but the solution is to fix that first then consider a bigger dish. Unfortunaelly I can only have a 6 footer, otherwise 8.5 would have been my choice.

For more info on the matter then ask Mr ..., well, the guy with the funny long last name who lives in Ct, who claims himself that someone else considers him an expert in the industry but fails to add to the same signature that his own 8 footer high quality dish was unable to get any S2 signal at all untill someone else came to his rescue. Beleive me, for less than that, people get killed back in the streets of Havana, lol. Welcome to America , Welcome to freedom, Welcome to the Internet where anyone can write anything (including me) and it even seems to matter nothing to anyone. He dicho!.

As usual I might be mistaken, but I am already used to it, lol.

 

[migold]

Thanks, HDFan, I didn't realize that one was up for replacement so soon. They might have it replaced before I get around to installing a larger reflector... As I am in no hurry, I expect that I will wait and see what the result is for SES-3. This issue was the only reason I have for upgrading the dish size at this time. In the meantime, I may try to pull it is with my 10 ft mesh dish, presently being used to receive W5 H2H programming. I was aware of the skew issue, but didn't want to change my skew setting to accomodate this one bird and compromise the excellent reception I was getting on all the others.
Thanks Again!

 

[hd fan]

you are welcome. you better wait IMO.

 

[jsattv]

Linuxman, great to hear from you again. I had kind of lost some interest in Satellite surfing but Last year in Oct I purchased an AZbox Premium Plus Rx and have had great success with picking up all kinds of MPEG -4 DVD-S2 Signals on various Satellites. I use Mike Kohl's Monthly Global Satellite Listings and The List as a reference for these Signals.

I had always had some trouble in pulling in Satellites way over to the West ie 125.0W on KU Band, so I went back to those great Tips you gave me back in Jan & Feb 2008 and completely re adjusted my Inclination and Declination on the 12 Ft Mesh Dish using the Sears Digital Level, and now I can track Sats from 55.5 over to 137.0W on Both C Band and KU Band. The HD Reception on Azbox is amazing - in fact seems a bit better than my Bell Sub dish for HDTV. Not sure if you remember me but those instructions & drawings on my Dish pictures that you as well as VommVoom & others gave me were extremely valuable and have left me with great Satellite reception for the most part, thanks.

 

[linuxman]

Linuxman, great to hear from you again. I had kind of lost some interest in Satellite surfing but Last year in Oct I purchased an AZbox Premium Plus Rx and have had great success with picking up all kinds of MPEG -4 DVD-S2 Signals on various Satellites. I use Mike Kohl's Monthly Global Satellite Listings and The List as a reference for these Signals.

I had always had some trouble in pulling in Satellites way over to the West ie 125.0W on KU Band, so I went back to those great Tips you gave me back in Jan & Feb 2008 and completely re adjusted my Inclination and Declination on the 12 Ft Mesh Dish using the Sears Digital Level, and now I can track Sats from 55.5 over to 137.0W on Both C Band and KU Band. The HD Reception on Azbox is amazing - in fact seems a bit better than my Bell Sub dish for HDTV. Not sure if you remember me but those instructions & drawings on my Dish pictures that you as well as VommVoom & others gave me were extremely valuable and have left me with great Satellite reception for the most part, thanks.

Glad I could be of help.