Bandstacking technology thoughts

[Corrado]

Ok, I keep reading about bandstacked LNBFs. I'm not really sure I understand what the advantage is. I have been reading here where many are experimenting with them. I understand how it works but what really is gained? From the pics I've seen posted it looks interesting.

Although I have no need for circular polarized LNBFs, it looks as though people are disassembling them for the insides. Are there linear ones too?

I have being thinking about playing with some multi-LNB brackets and I thought I was missing some point.

 

[gabshere]

i also would like to try several maybe two of each 2 ku and 2 c band and see if it will work with a distribution to several receivers like i think it would.

so i don't know if a stacked lnb will go through a 3X4 to several receivers but sounds like it would . and don't know if the other receivers would have problems with the stacked lnbs on the same switch.

i will have to put it on my project to try for fall/winter/spring

 

[Anole]

If you find the 119/121 LNB assembly from some of the SuperDishes, the 121 LNB is FSS or linear.
Another source, for an Eagle Aspen LNB is Global-CM.
It has a different horn. Not sure which Dish application that was made for.

One advantage is that only a single cable is needed from the LNB.
For multi-dish, multi-LNB, or multi-receiver applications, you usually need two cables to get both V and H polarities.
And LNBs with two outputs!
Two cheap 4:1 diseqc switches and a fancy ecoda 22khz switch could get you eight LNBs connected to one receiver.
That configuration is appealing to some.

In another configuration, where I want to feed 3 or 4 LNBs to 4, 8, or up to 12 receivers, recycled Dish-brand switches could be used with bandstacked LNBs to simplify the hardware.

Not every configuration is an ideal candidate for bandstacked LNBs.
I see there is one C-band LNB available. If it works, that's great.
If you need flexibility to test other LNBs, too bad.

I think bandstacked LNBs were introduced (commercially) by Dish to cut down on cabling and allow longer cable runs.
Since there is no voltage-switching point, voltage drop in several hundred feet of coax was no longer a limiting factor

As noted, not every receiver is bandstacked-friendly.
If that's the case, don't consider it.

I guess it's just a solution looking for a problem.

 

[jerryt]

Advantages
1) I have 16 satellites on one 4 X 1 diseqc switch and four 4 X 8 multiswitches

2) Eagle aspen FSS P870 LNB's are going for $9.00 on Ebay, very narrow, for close spacing of satellites. They are also very strong.

Work arounds
If a receive does not list support for band stacked LNB's, No Problem, the convertion formula is easy.

Linear (FSS)
24600 - (Horizonal freq) = (Band Stacked freq as a Vertical)

Circular (DBS)
25600 - (Horizonal freq) = (Band Stacked freq as a Vertical)

 

[Mr Tony]

jerry

Will the bandstacked LNB do H too? Just wondering in regards to the multiswitch

 

[jerryt]

jerry

Will the bandstacked LNB do H too? Just wondering in regards to the multiswitch

The LNB itself only sees the freq not the H or V (Voltage)

All my receivers are satellite cards. So to add a satellite to the H output on the multiswitch, is simple. Takes 10 seconds;

Open the Dish Pro modified Satellite init file (A standard init file where all the H freq's where converted to V's by the formula) in Notepad and do an edit, where you find all the V's and change for H.

Done, now I can use the H output.

 

[Corrado]

If you find the 119/121 LNB assembly from some of the SuperDishes, the 121 LNB is FSS or linear...

That's right...I forgot about the SuperDish FSS LNB. I have one out in the shed.

 

[Anole]

damn, he's sneaky !

I have 16 satellites on one 4 X 1 diseqc switch and four 4 X 8 multiswitches

I've been puzzling with that answer for a while.
I just got it!
He could actually have up to eight receivers too, I believe.

Jerry - you're as clever as they come! - :up

 

[Mr Tony]

The LNB itself only sees the freq not the H or V (Voltage)

All my receivers are satellite cards. So to add a satellite to the H output on the multiswitch, is simple. Takes 10 seconds;

Open the Dish Pro modified Satellite init file (A standard init file where all the H freq's where converted to V's by the formula) in Notepad and do an edit, where you find all the V's and change for H.

Done, now I can use the H output.

oh...Since I'm not using PC cards that wouldn't work. But I'll have to see if that works to have 2 on a multiswitch. I know when I was working with a 3x4 multiswitch and a Diseqc (having one LNB as V only and one as H only on a multiswitch) the receiver could not decode one side of the multiswitch for some odd reason.

 

[jerryt]

oh...Since I'm not using PC cards that wouldn't work. But I'll have to see if that works to have 2 on a multiswitch. I know when I was working with a 3x4 multiswitch and a Diseqc (having one LNB as V only and one as H only on a multiswitch) the receiver could not decode one side of the multiswitch for some odd reason.

It works with STB, but in a different way. Blind scan H freq's only or V freq's only and you have two satellites.

If the STB doesn't let you pick H or V only, then just disconnent one lnb during the blind scan.

You have to adjust the scanned freq range up to include the band stacked freq's.

 

[jerryt]

If you find the 119/121 LNB assembly from some of the SuperDishes, the 121 LNB is FSS or linear.
Another source, for an Eagle Aspen LNB is Global-CM.

Anode, this is what I would recommend to people from a superdish. It is the 105 Superdish "105 LNB" without the bracket. Also it is my second choice after the P870.

 

[Anole]

Not a lot of 105 SuperDishes on the West coast, but I'll keep a lookout.
Thanks.

Jerry, is this the way you are wired up?

Decoding table:  

[FONT=Courier New] LNB
LNB 01    diseqc 1     22k off    V: 13 volts
LNB 02    diseqc 1     22k off    H: 18 volts
LNB 03    diseqc 1     22k on     V: 13 volts
LNB 04    diseqc 1     22k on     H: 18 volts
LNB 05    diseqc 2     22k off    V: 13 volts
LNB 06    diseqc 2     22k off    H: 18 volts
LNB 07    diseqc 2     22k on     V: 13 volts
LNB 08    diseqc 2     22k on     H: 18 volts
LNB 09    diseqc 3     22k off    V: 13 volts
LNB 10    diseqc 3     22k off    H: 18 volts
LNB 11    diseqc 3     22k on     V: 13 volts
LNB 12    diseqc 3     22k on     H: 18 volts
LNB 13    diseqc 4     22k off    V: 13 volts
LNB 14    diseqc 4     22k off    H: 18 volts
LNB 15    diseqc 4     22k on     V: 13 volts
LNB 16    diseqc 4     22k on     H: 18 volts[/FONT]

 

[jerryt]

Not a lot of 105 SuperDishes on the West coast, but I'll keep a lookout.
Thanks.

Jerry, is this the way you are wired up?

Decoding table:  

[FONT=Courier New] LNB
LNB 01    diseqc 1     22k off    V: 13 volts
LNB 02    diseqc 1     22k off    H: 18 volts
LNB 03    diseqc 1     22k on     V: 13 volts
LNB 04    diseqc 1     22k on     H: 18 volts
LNB 05    diseqc 2     22k off    V: 13 volts
LNB 06    diseqc 2     22k off    H: 18 volts
LNB 07    diseqc 2     22k on     V: 13 volts
LNB 08    diseqc 2     22k on     H: 18 volts
LNB 09    diseqc 3     22k off    V: 13 volts
LNB 10    diseqc 3     22k off    H: 18 volts
LNB 11    diseqc 3     22k on     V: 13 volts
LNB 12    diseqc 3     22k on     H: 18 volts
LNB 13    diseqc 4     22k off    V: 13 volts
LNB 14    diseqc 4     22k off    H: 18 volts
LNB 15    diseqc 4     22k on     V: 13 volts
LNB 16    diseqc 4     22k on     H: 18 volts[/FONT]

WOW !! Anole you are a fast learner.

Yes that looks fine, you realized I already posted the "Decoding Table" as you call it. Found it;
LNB settings
1 = Committed 1, Switch 0, Polarity V.
2 = Committed 1, Switch 0, Polarity H.
3 = Committed 1, Switch 11700, Polarity V.
4 = Committed 1, Switch 11700, Polarity H.
5 = Committed 2, Switch 0, Polarity V.
6 = Committed 2, Switch 0, Polarity H.
7 = Committed 2, Switch 11700, Polarity V.
8 = Committed 2, Switch 11700, Polarrity H.
9 = Committed 3, Switch 0, Polarity V.
10 = Committed 3, Switch 0, Polarity H.
11 = Committed 3, Switch 11700, Polarity V.
12 = Committed 3, Switch 11700, Polarity H.
13 = Committed 4, Switch 0, Polarity V.
14 = Committed 4, Switch 0, Polarity H.
15 = Committed 4, Switch 11700, Polarity V.
16 = Committed 4, Switch 11700, Polarity H

use 13700 instead of 0, 0 only works in MyTheatre. Also if you have a switch on/off setting then use that instead of the SW settings (Simplier).

I just stole your wonderful drawing as my own, Ha Ha !!. Could you draw me one with all sixteen LNB's Please.

Are you using Visio for the drawings?

 

[qwert1515]

Are you using Visio for the drawings?

I am pretty sure Anole uses paint, but I am still going to be amazed when he says it

 

[Anole]

careful what you ask for

I don't have any proper tools, and a buddy does excellent work in PAINT.
So, I thought I'd give it a try.

This isn't first rate, but it's good enough to show the idea.
Feel free to punch it up if you like.
(I'll even send anyone who wants, the GIF source file)

 

[updatelee]

starchoice uses bandstacked linear lnb's as well. they make a single and a double. the double is 4deg spacing and 22khz controled.

 

[qwert1515]

I don't have any proper tools, and a buddy does excellent work in PAINT.
So, I thought I'd give it a try.

This isn't first rate, but it's good enough to show the idea.
Feel free to punch it up if you like.
(I'll even send anyone who wants, the GIF source file)

Very well done Anole as always.

 

[jerryt]

I don't have any proper tools, and a buddy does excellent work in PAINT.
So, I thought I'd give it a try.

This isn't first rate, but it's good enough to show the idea.
Feel free to punch it up if you like.
(I'll even send anyone who wants, the GIF source file)

Thanks, super job !!

 

[Anole]

thanks for the kind words

Thanks again.
Let me know if you think that 16-lnb drawing needs more details.


The specs on those LNBs aren't all that great.
They're listed as having 0.9db noise level.
People pay extra for Invacom LNBs with 0.3db
You think the LNBs are better than their spec, or how do you explain their performance?


The more you write and the more pictures you show, the better everyone will understand, so don't be shy.
Maybe more details about how you hacked up those LNBs and their pipes.
I can see you've done some major surgery on some of them.
Do you have or can you make, some pictures showing some of the steps cutting them up?

 

[jerryt]

The specs on those LNBs aren't all that great.
They're listed as having 0.9db noise level.
People pay extra for Invacom LNBs with 0.3db
You think the LNBs are better than their spec, or how do you explain their performance??

Those numbers are advertized, and I am sure they would not lie (wink, wink). I am going by how they perform in the real world (My back yard).
1) I could not find ANY lnb that would tune 87 in a multifeed where 87 was not in the center, The P870 (Or any FSS 105 type) works perfectly. What does that tell you?
2) These Band Stacked FSS LNB's have given me the highest signal signal strength I have ever had to date. Much better then my 0.3 Invacom. What does that tell you?

May be Iceberg can comment on his exiperence with these P870's

Disclaimer - I don't get as many channels as before, the unwatchable weak channels don't scan in. So that may be were the 0.9 noise level kicks in.

The more you write and the more pictures you show, the better everyone will understand, so don't be shy.
Maybe more details about how you hacked up those LNBs and their pipes.
I can see you've done some major surgery on some of them.
Do you have or can you make, some pictures showing some of the steps cutting them up?

Those super narrow "cut down" (hacked, as you say) 121 FSS LNB's were an experiment. They were a lot of work and were only needed for my custom multifeed bracket. There is nothing to gain for anyone else.

If you want a bandstacked narrow LNB, buy the P870 or the Superdish 105 LNB's. If you want Multifeed 2 degree spacing, I suggest T90 with those two types of LNB's.