Best Way to Receive Whole Ku Arc With Fixed Dishes?

[linuxman]

I spoke with Anole on the phone, and he said I was asking the wrong question. :yikes:

He said it was premature to talk about moving the support platform.

He also suggested the reason why the outer LNBFs were pointing at the upper part of the dish is because they weren't high enough, and with the black holders going in as much as high with each turn of the adjuster, that was where part of the problem was.

So I switched out 79W using a 5 inch bolt and a hose clamp. It now rises straight up as needed. I am at the end of the bolt, and as you can see below, it is still pointed at the upper part of the dish just a little, and it is also pointed half way out from center horizontally.

Theory would say, I need to go higher and farther out on the conduit. But that's theory.

In reality, I gained another 10% SQ on the N transponder and am at a rock solid 30% now.

I probably won't get much more done outside for a few days because it is supposed to rain for 4 or 5 days now. Temps will be nice, but rain poses problems for receivers.

Take a look at the pictures, and let's discuss where I go from here.

 

[voomvoom]

Fred, I think you need to turn the support bar upward from the ends. In other words, when you look at the dish from behind the lnbf's, the bar looks almost straight across. I think from that view the ends should arch up. That way the lnbf's could possibly be about the same distance on the bolts from the bar? And still be pointing in the same general direction...? Maybe...? I really don't know how to explain what I'm trying to say?
But, it looks Great!

 

[voomvoom]

Looking at the 7th picture, with the yellow arrow pointing up, and the blue arrow that points down (forget the blue arrow that points up). That looks like the way to go, to do what I'm trying to say...??
If it won't adjust that way, then twist the ends upward...?

 

[pendragon]

I also may have another solution. Pay close attention to the last picture and tell me which way to move the support platform. Up tilting the LNBFs more towards the point Pendragon plotted out in his graph, or down more towards the "center" circle of the dish. The yellow arrow points at the mark where I moved it to from it's original position the OEM installer had the support platform.

What do you think Pendragon?

Tell me which way to move the platform? Also tell me if you think I have it as good as I am going to get and forget about 79W and 103W.

A side shot of the dish and arm profile would make the angles a little more obvious. Also if you could mark approximately where the LNBFs are point on one of the front pictures, that would help.

As I posted in the dish comparison thread, I messed around on my 1.2m offset for a few minutes today. I was lying in a rather awkward position flailing with a LNBF in one hand and the meter in the other, so I wasn't able to make any meaningful location measurements. The focal clouds seemed a little weird, but that may just have been my inverted brain. I always ended up pointing the offset LNBF higher than I initially guessed for the best signal, although the actual height wasn't that much different. I think that makes theoretical sense.

With regard to the range of arc you should expect on an offset parabolic dish, my initial real-world results indicate a 10 degree offset is a reasonable limit, although you might squeak out a little more if the transponder is bright enough. At 10 degrees your 1.8m parabolic may start looking like a 76cm on-axis. I emphasize this is only a preliminary result.

 

[linuxman]

Thanks for the suggestions Guys!

After thinking the situation over last night and this morning, I have to keep reminding myself what this project is for.

I started out to find the best way to receive the whole Ku arc on fixed dishes. The purpose was to watch TV easily and conveniently. The purpose was not to see how many LNBFs I could hang on a single dish.

The other thing I have to keep reminding myself of is all the new S2 signals now coming out of the sky. The S2 signals need a well tuned dish/LNBF in order to receive them.

The 10 LNBFs currently on the Prodelin not counting the 79W LNBF, with a little more tweaking now that I know what to do are performing and the outer ones will perform exactly as if they were on their own separate dish with all the Signal Quality one could expect from a separate well tuned dish on each satellite.

With that in mind, I think I will shift the center to 93W and cover the arc from 83W to 103W with 11 LNBFs with superb signal on every one of them. I can also hang some DBS LNBFs for the free channels on those birds on this dish. Maybe 110W could go on the Prodelin. Those satellites have a lot more power than our linear birds and will receive signal if you just point them in the general direction.

The rest of the arc will be covered on my Primestar dishes.

That would put 79W, 74W, 72W and estrella on one dish. Yes, I think I have a solution for 72/74 that will work very nicely.

30W and 43W would go on a separate dish.

On the West end, that would leave:
105W
107.3W
111.1W
113W
116.8W
119W
121W
123W
125W
127W
129W
148W
all to be divided the best way possible for the whole Ku arc.

Some of the above are optional, but if they can be worked in, they will be.

 

[Anole]

as long as you're at it . . .

Considering the geometry of your current hardware...
... and considering you are going to discard all our settings to re-aim the dish...
I see great merit in Voom's suggestion.

Fred, I think you need to turn the support bar upward from the ends. In other words, when you look at the dish from behind the lnbf's, the bar looks almost straight across. I think from that view the ends should arch up. That way the lnbf's could possibly be about the same distance on the bolts from the bar? And still be pointing in the same general direction...? Maybe...? I really don't know how to explain what I'm trying to say?
But, it looks Great!

I find his explanation quite clear, but for anyone who doesn't . . .
Looking from the west side of the dish, rotate the LNB support tube you made, about 20° clockwise, or as needed.
This brings the tips upward.
That should help the line of LNBs follow the desired arc without having to be mounted outrageously high above the LNB mount tube (you made).

Well, it was just a thought.

edit: oh, and as for circular birds, I wouldn't doubt you could get 110°, as is.
Give a shot at 119°, and let us know.

 

[Keith Brannen]

oh, and as for circular birds, I wouldn't doubt you could get 110°, as is.
Give a shot at 119°, and let us know.

Should be no problem to get 110 (would be 17 degrees off-centre) or 119 (would be 26 degrees off-centre). Currently, I have an LNB (61.5) roughly 22 degrees off-centre on an 80cm Fortec dish and am getting quality levels of mid-60s as the lowest, 90 as the highest, with most in the mid-70s range, on my Pansat. At one time (before I moved it to another dish), I had 129 at 24 degrees off-centre (did it ever look funny stuck so far out from the arm) and was getting signals (at least on WOUB when it was FTA) in the 60s.

 

[linuxman]

Fred, I think you need to turn the support bar upward from the ends. In other words, when you look at the dish from behind the lnbf's, the bar looks almost straight across. I think from that view the ends should arch up. That way the lnbf's could possibly be about the same distance on the bolts from the bar? And still be pointing in the same general direction...? Maybe...? I really don't know how to explain what I'm trying to say?
But, it looks Great!

Thanks Al!!

If I were going to continue to pursue 12 degrees out from center, it would make sense to raise the ends of the conduit, but for 10 degrees out except for DBS, the LNBFs won't be that far above the conduit to warrant bending the ends up. If need be for the DBS LNBFs, I can build a riser.

The other reason for not wanting to bend up the ends is that the ground clamp I am using to secure the upright bolt doesn't have a swivel on it. It holds the bolt perpendicular to the conduit. If I bend the ends up, the bolts will be cocked forcing the LNBFs closer together, and at this point I don't want to re-design the clamp assembly.

I like the black LNBF holders. They make it very easy to slide in and out, and for skew adjustment. Hose clamps work well too, just not as easy to work with.

Maybe SatelliteAV can manufacture some L shaped black holders for projects like these?

Probably just the last two LNBFs on each end will require the hose clamp change out.

Anole wrote:

Considering the geometry of your current hardware...
... and considering you are going to discard all our settings to re-aim the dish...
I see great merit in Voom's suggestion.

Yes there is merit in Al's suggestion, I just don't think it necessary to implement it in this scenario.

I also think it makes more sense to re-aim the dish to get a good solid 22 degrees of the arc with 11 LNBFs on a single dish.

I find his explanation quite clear, but for anyone who doesn't . . .
Looking from the west side of the dish, rotate the LNB support tube you made, about 20° clockwise, or as needed.
This brings the tips upward.
That should help the line of LNBs follow the desired arc without having to be mounted outrageously high above the LNB mount tube (you made).

Well, it was just a thought.

I thought Al's explanation quite clear too!

In order to rotate the conduit 20 degrees, would require new holes drilled and while I am not objectionable to do that, I don't think it necessary to do what I want to achieve for the above reason in part with the clamps, and another, I would need to make a totally new conduit for fear that the holes would weaken the strength of the existing piece.

edit: oh, and as for circular birds, I wouldn't doubt you could get 110°, as is.
Give a shot at 119°, and let us know.

Sure, it is worth a shot. :up

Keith Brannen wrote:

Should be no problem to get 110 (would be 17 degrees off-centre) or 119 (would be 26 degrees off-centre). Currently, I have an LNB (61.5) roughly 22 degrees off-centre on an 80cm Fortec dish and am getting quality levels of mid-60s as the lowest, 90 as the highest, with most in the mid-70s range, on my Pansat. At one time (before I moved it to another dish), I had 129 at 24 degrees off-centre (did it ever look funny stuck so far out from the arm) and was getting signals (at least on WOUB when it was FTA) in the 60s.

I'll bet it did look funny!

That gives me hope that maybe I can get some of the other DBS birds on here too if I build a riser on the ends for that purpose.

The DBS birds aren't as critical for signal strength because I won't be trying to pull out any S2 signals off those satellites. All I need from them is enough SQ to be watchable.

 

[jamestheman]

You should come to my area. I live in tyler texas and there are at least 40 primestars in a mile radius around my house, about half the homes have one, I am actually thinking of going and asking them all if I can take it down, you know they arent using them as no one around here does fta! LOL!!

 

[gremlin411]

Hey jamestheman
My dad lives in jacksonville. Next time I go see him I will let you know and we can go look for them.

 

[linuxman]

I got the lnbf holders changed out to hose clamps, but it did not help the signal performance like I thought that it might. Actually the performance was about the same, and much easier to work with the black holders.

I have included pictures below to try and better demonstrate where the 3 outer lnbfs on each side points to on the dish surface.

I re-aimed the dish to 93W as the center, but the characteristics of the signal was changed enough that I moved the aim back to 91W. My true south satellite.

The seven center lnbfs have signal that are the envy of any satellite hobbyist. However, further out than that the signal starts dropping off. Course part of that is just me. I have a problem when it comes to satellite signal. When I see all transponders in the center 7 with 90-99% SQ on my Pansat, 60% seems low to me.

Some would say that I am just a little too picky.

After looking at the numbers, and some reflection, I have decided to change the plan and scope somewhat.

Part of the reason for the change, is that I began studying what is being broadcast on the satellites that I had the great signal on. Let's face facts for a minute.

There is primarily news and sports feeds on 83W, 85W, 89W, 91W, 93W, and 95W.

The point I am making is that I first started out this project with the best way to get all Ku satellites with fixed dishes. The answer is of course subjective, but I now realize that the discussion would be better aimed towards the best way to get the most popular satellites on fixed dishes.

That is still subjective, but at least time and money will be spent towards viewing the satellites that my family and I are most interested in, and making the channels easily accessible with switches instead of moving the dish.

So for me to answer the discussion about getting the most Ku satellites with Ku fixed dishes, is to select 8 to 12 of the most popular satellites that you and your family will watch most of the time, and put 2 - 4 lnbfs on separate smaller fixed dishes that are more suitable for multi-lnbf configurations, and have one motorized ku dish for the rest of the arc that will only be watched occasionally.

Smaller Ku dishes are readily available by finding Primestar dishes, or by purchasing them from our sponsors. I recently bought a Glorystar system from SatelliteAV that included a 90CM dish that I am going to include as part of this total system using the SL2s and still be able to have the dedicated Glorystar receiver pointed to 97W and 101W.

So to wrap up this post, because it is starting to look like a presentation paper, the project and scope is changing, and will include fixed C-Band dishes when I am finished thanks to SatelliteAV making the voltage controlled dual ouput C2 C-Band LNBFs available to us again. :up

I will be back with my selection of fixed Ku and C-Band satellites dishes a little later.

When I am finished, my family will only have their favorites to select from in the receiver, and will only have access to fixed dishes. I on the other hand will still have one moving C-Band dish, and one moving Ku dish along with the fixed dishes.

That of course does not count my scanning dish in the front of the building.

Here are the pics:

 

[pendragon]

The seven center lnbfs have signal that are the envy of any satellite hobbyist. However, further out than that the signal starts dropping off. Course part of that is just me. I have a problem when it comes to satellite signal. When I see all transponders in the center 7 with 90-99% SQ on my Pansat, 60% seems low to me.

I should have realized it before, but an offset dish is generally going to lose gain at a faster rate off-axis than a prime focus. The vertical orientation throws away gain on the sides that becomes more important the farther one moves off-center. This is borne out with new prime focus measurements I made yesterday. I think you're squeaking everything out of the dish that is there.

 

[Tron]

I'd love to see the performance of a C2 LNBF or two mounted on that Prodelin

 

[Anole]

while you are at it:

I'd love to see the performance of a C2 LNBF or two mounted on that Prodelin

Well, that does raise an interesting question.
Is there any one C-band bird that might perform well on a 6' dish?

What about two at 4° spacing?
Okay, best case: three in a row at 4° spacing?
Was just looking at your LNB picture above, and so you know where they'd need to be.

This would bring back the need for conical scalars.

 

[linuxman]

I should have realized it before, but an offset dish is generally going to lose gain at a faster rate off-axis than a prime focus. The vertical orientation throws away gain on the sides that becomes more important the farther one moves off-center. This is borne out with new prime focus measurements I made yesterday. I think you're squeaking everything out of the dish that is there.

Yes I noticed that it was the Vertical signals that seem to suffer more at the outer ends. I believe I have it tuned as well as I can get it.

Tron wrote:

I'd love to see the performance of a C2 LNBF or two mounted on that Prodelin

I don't have a C2 just yet, but will in the near future.

Anole wrote:

Well, that does raise an interesting question.
Is there any one C-band bird that might perform well on a 6' dish?

What about two at 4° spacing?
Okay, best case: three in a row at 4° spacing?
Was just looking at your LNB picture above, and so you know where they'd need to be.

This would bring back the need for conical scalars.

It is an interesting thought, but that brings up the question as to whether it would perform well enough to receive S2 signals?

I have always operated under the assumption that 7.5 foot was the bare minimum to get reliable C-Band signals. There are also S2 signals that our friend and forum member Photoman76 can't lock on his 7.5 footer.

I could be enticed to put it in the lineup as a C-Band dish if there were Ku satellites that met the criteria in my above post about how popular the satellites were, and if they were in the 6 degree out from center of the dish range?

103W C-Band might fill that spot if I thought I could get those C-Band signals with good quality signals, and the possibility of no S2 signals for a while. That would allow for 97W, 101W, and 103W, Ku satellites to be added on.

Another possible C-Band scenario might be either 127W with adjacent Ku signals 125W, 129W, and 125W. But there again what are the possibilities of S2 C-Band signals there.

The final possibility might be 121W C-Band with it's adjacent Ku satellites close by.

Let me think about those possibilities.

While I don't have a C2 yet, I do have a CK-1 that would tell me a good indication.

Any of you guys that have a 6 foot dish whether Prime Focus, or off-set, let me know what you think of it's C-Band performance?

Thanks!

 

[linuxman]

Well I have a possible proposal for my new dish farm layout.

My wife gave me a gift for Valentine's Day. The gift is allowing me to take the two C-Band NPRMs from the Prodelin and my 10 foot scanning dish in the parking lot and to plant permanent posts to mount those two dishes on. That will free the mounts up for use on the roof for C-Band fixed dishes. See pic below of the dishes and mounts.

I also got most of the steel needed to make a third NPRM mount the other day for almost nothing. So I will have an additional 3 C-Band dishes on the roof.

The 4DTV dishes will remain for 4DTV unless their prices get any more out of control than they are. Then they will become fixed dishes too.

My plan also includes pointing the Prodelin at 121W for C-Band using a C-2 when they come in, with additional SL2 LNBFs pointed at 123W, 125W, and 129W, and all the DBS LNBFs I can hang from it. I am going to test that with a CK-1 that I have here, but regardless, the Prodelin stays put for those positions. That should solve any problems with reception on any of those Ku satellites.

I will leave my Geosat Pro 90cm dish where it sets for 97/101W as it was designed for my Glorystar system, but by putting SL2s LNBFs on it, I can also integrate it into my total system.

I will also leave my motorized Primestar where it sets in the picture for use in the system to receive all Ku satellites not covered by fixed dishes.

I will have a fixed 84e on Hispasat.

A second fixed 84e for 72/74W. Yes I know 72/74 will be a little tight, but I have a workable solution I think.

A third fixed 84e on 83W/89W.

A possible fourth 84e for 103W or 105W.

I will have a total of semi-fixed C-Band dishes including the Prodelin which will be on 121W,
with the Perfed Birdview on 87W for ThisTv and RTN S2, the Pinnacle will be on 91W.

The final 3 fixed C-Band dishes will be pointed to a choice of these remaining satellites:

107.3W for ASTN and whatever else
105W for whatever is there
103W pretty sure one will go here for ION
99W for PR NETS
95W for the Equity stuff

So three remaining dishes out of 5 choices. Ah decisions, decisions!

Probably will end up with 103, 99, and 95 as the choices. Unless someone convinces me differently or something changes dramatically. All the fixed dishes will have actuators on them, and will be set on the arc in the event of re-positioning at any time.

All of these dishes will go to 3 receivers. Two in my room, and one in the family room. I will have room for one more expansion receiver.

I will also have one remaining moving C-Band dish which will be my solid Birdview to be used in conjunction with my motorized primestar.

So let me know what you think?

See the picture and layout diagram below.

 

[voomvoom]

I like the plan Fred...!!

 

[Anole]

bad news:

As much as I'd love to see a Prodelin 6' dish get some C-band, even just one satellite, I guess that's to be determined.
But, do consider how close to that central C-band LNB you can put a Ku-band LNB.
I don't think you can snuggle up at 2° spacing.
That's sort of why I suggested 4° between C-band birds, on the Prodelin.
Or any dish/BUD, come to think of it.

 

[linuxman]

As much as I'd love to see a Prodelin 6' dish get some C-band, even just one satellite, I guess that's to be determined.
But, do consider how close to that central C-band LNB you can put a Ku-band LNB.
I don't think you can snuggle up at 2° spacing.
That's sort of why I suggested 4° between C-band birds, on the Prodelin.
Or any dish/BUD, come to think of it.

The CK-1 is about 2.375" diameter which means from the center out is 1.1875". The SL2s are 1.5" wide, so .75" from center equals 1.9375" from center to center if lined up perfectly next to each other.

With that in mind also consider that 121W is 35.1 degrees elevation for me while 123W is 33.9 degrees elevation. That's 1.2 degrees that 123W will need to be elevated above where 121 sets.

It will be a close fit, but with the right holders, it should work fine. There won't be any room for a scaler unless it is cut to fit around the Ku LNBF.

If it warms up a little, I am going to try the experiment this afternoon.

 

[Mr Tony]

The final 3 fixed C-Band dishes will be pointed to a choice of these remaining satellites:

107.3W for ASTN and whatever else
105W for whatever is there
103W pretty sure one will go here for ION
99W for PR NETS
95W for the Equity stuff

So three remaining dishes out of 5 choices. Ah decisions, decisions!

Probably will end up with 103, 99, and 95 as the choices. Unless someone convinces me differently or something changes dramatically. All the fixed dishes will have actuators on them, and will be set on the arc in the event of re-positioning at any time.

Linuxman
Me personally would do 107, 103, 99

I know you mentioned 95 for Equity but since the Equity/RTN splitup there isnt much on there that isnt already somewhere else. They're down to 10 channels on that TP (from 16). What is on there is Daystar, 5 UNivision feeds and a Telefutura. That leaves 3 English channels left.
WMQF & WNGS are on G18
WBIF is now a "This TV" affiliate which (as you posted above) is already on a dish at AMC3 C-Band (and G18)

so I would use 99 for the nets and the feeds (some sports feeds show up there on occasion), 103 for ION and RFD TV and 107.3 for ASN, some French channels and whatever else is up there

105 C-Band is mainly 4DTV stuff