Dual C-band Feedhorns... (1 Viewer)

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sergei

SatelliteGuys Pro
Aug 29, 2007
1,266
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iowa
I ordered the Chaparral, two bsc211's, and a five pack of 3X4 multiswitches. :)

Now we wait. :D

Here's another optional setup for the Chaparral for two receivers...I also have drawing for attaching more receivers.
 

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voomvoom

SatelliteGuys Master
Lifetime Supporter
May 18, 2004
6,660
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Lizella, Georgia Republic
Because they are not voltage switched like the 13/18v lnb's. They are both getting 18 volts from the receiver. The switching is between V and H, just like a servo motor, only there is no servo motor. And this is assuming these are single polarity lnb's, like the Norsats..?

And, these are analog receivers with the ability to set up for Internal V/H switching....

I should leave this alone, cause I'm guessing....??????
 

sergei

SatelliteGuys Pro
Aug 29, 2007
1,266
5
iowa
I guess I may have over looked what type of receiver your planning on using so in your case this may not work for your setup. On my 920 I have separate connectors for the H & V so this works for me. I got this setup from a Chaparral engineer last year and it was from one of there manuals, I just thought it might work for you.
 

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voomvoom

SatelliteGuys Master
Lifetime Supporter
May 18, 2004
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Lizella, Georgia Republic
And stogie, you are right in your thinking, that diagram would send 13v to the lnb (lnbf) from a DVB receiver. Whether it's the good single polarity Norsats, or a 13/18v switched lnbf. It would only get 13v to to vertical side, and that would probably cause a lack in performance on a single polarity lnb that expects 18v to run proper? The operation specs on a Norsat are from 15-24v, I think?

Edit: I have problems with my Vertcal side at times, using the Pansat 9200 and sending the 13v to an lnb that needs 18v is probably not such a good idea. Although it works for the most part, the lower voltage could possibly damage the lnb in the long haul. On a different dish, using a 922 4dtv I'll get signals that nearly blow the meter on V and H, but with the dish the Pansat and V-Box are using the H usually blows while the V has it's problems. I've switched the cables and the V side still has this problem, so I'm sure it must be the 13v that is causing this. I need to either get an in-line power inverter (or whatever it's called) for 18v, or get a powered multi-switch and modify it like Fred did...?
 
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Lone Cloud

SatelliteGuys Pro
May 23, 2008
701
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I read this whole thread and was lost after the first half of the first page. The only thing I got was that they sell dual feedhorns that accomodate two lnbs one for H and one for V.

I have fta equipment. No 4dtv. I have two dishes on my roof - one a Ku 1 meter dish with a stab hh120 motor and my recently installed Birdview 8 1/2 footer. Unless its simple to do, my thinking is to keep the Ku and C dishes separate.

What would be a workable setup for the big dish into one receiver with a dual C-band feedhorn? Will a diseqc switch work? One cable to the dish?
What lnbs would be a good value?

Maybe I need a drawing.
 

stogie5150

Crazed Cajun Rebel
Jan 7, 2007
3,819
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Slidell,LA
I read this whole thread and was lost after the first half of the first page. The only thing I got was that they sell dual feedhorns that accomodate two lnbs one for H and one for V.

I have fta equipment. No 4dtv. I have two dishes on my roof - one a Ku 1 meter dish with a stab hh120 motor and my recently installed Birdview 8 1/2 footer. Unless its simple to do, my thinking is to keep the Ku and C dishes separate.

What would be a workable setup for the big dish into one receiver with a dual C-band feedhorn? Will a diseqc switch work? One cable to the dish?
What lnbs would be a good value?

Maybe I need a drawing.

That is exactly my setup. I use a Dual Voltage controlled feed right now, so the thought is to go with a dual separate to try and drag in more signal. The gist of it its you have two coaxes ( H and V) coming out of the lnb's at the dish, then you run them to a multiswitch to distribute them to multiple receivers on one coax each. Mine will be in my attic. Since a DVB receiver puts out 13V on one leg and 18V on the other leg, and the c-band LNB's need 18v to work properly, you need to add voltage to the 13V side. This is done BETWEEN the dish and the multiswitch, NOT between the multiswitch and the recievers. Then when the DVB receiver asks for the polarity, the LNB's will be provided with the correct voltage to work properly.

The other way is to modify a POWERED multiswitch to put out 18V on both legs to power the LNB's. But that, alas, is beyond my skillset. I can put a power inserter in the coax to the LNB, no problem. :D

I'll have pics when I do mine, I am waiting on Sadoun to get my power inserter here, so stay tuned. :)

That is if a hurricane doesn't come along and blow my dish away....
 

stogie5150

Crazed Cajun Rebel
Jan 7, 2007
3,819
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Slidell,LA
I just looked at the weather a while ago, and the computer models don't look good for your area Stogie. :yikes:

Fred they don't know....as far away as it is, it could go anywhere. Everyone is so spooked from the Katrina experence down here, now whenever a storm gets in the gulf they FREAK.

Folks need to calm down, have a plan, and execute it when needed. I have all my plywood cut for my windows, my shed door braces ready, plenty water and food. I will move the paraclipse to Due South, take the Ku dishes off the motors and leave the motors on the poles. If its a category 3 or above, I am on my way to Elizabethtown, KY. A friend of mine I grew up with lives there now, and he already has clean sheets on the bed for me. :)

But its Still a LONG way from that yet.:cool:
 

linuxman

SatelliteGuys Pro
Jul 16, 2006
3,903
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North West of St. Louis, MO
Fred they don't know....as far away as it is, it could go anywhere. Everyone is so spooked from the Katrina experence down here, now whenever a storm gets in the gulf they FREAK.

Folks need to calm down, have a plan, and execute it when needed. I have all my plywood cut for my windows, my shed door braces ready, plenty water and food. I will move the paraclipse to Due South, take the Ku dishes off the motors and leave the motors on the poles. If its a category 3 or above, I am on my way to Elizabethtown, KY. A friend of mine I grew up with lives there now, and he already has clean sheets on the bed for me. :)

But its Still a LONG way from that yet.:cool:
Well at least you have a plan. That's more than a lot of folks will have.

Just the thought of another Katrina gives me a bad feeling. We didn't have contact with my wife's sister who just lives a few miles from you for about 4 days, and that had the whole family upset.

We'll hope it goes to a place where there is a lot of open country for it to land.
 

truckracer

SatelliteGuys Pro
Sep 17, 2004
4,338
351
Charleston wv
I have discovered a problem with using passive multiswitch on my c-band side. Since I am under powering my vertical lnb with 13v, I have noticed that I have no problems with the pansat 9200.

When i connected my fortec ultra, Vertical signal quality jumps in and out locking and unlocking just on the vertical tp's. Horizontal is fine.

The fortec must be dropping just below the vertical lnb's critical threshold of operation due to the differences in voltage output that varies from receiver to receiver.

I am going to have to run either a modified powered switch or power inserter to get a full 18V to the vertical lnb.

Interesting enough, the Norsat ku lnbs seem to run out of spec just fine on vertical with the fortec. The DMS BSC-211 is dropping out with the fortec ultra on Vertical.

I thought also it may be the differences in the tuners of the two receivers maybe the db level is too low for the fortec? The fortec seems to have a superior tuner to the pansat 9200.
 

Lone Cloud

SatelliteGuys Pro
May 23, 2008
701
18
I am Still Interested in....

I am still strongly considering this approach, given the fact I don't have any polarotor control on my FTA receiver boxes. However, all this talk about 13v and 18v kind of rattles me.

It occurs to me also that I havent' seen any shootout or comparison review of Regular feedhorns and Duals.

I'm counting on you guys, because I certainly don't know enough about it.

I don't want to either underpower or burn something out.
 

ACRadio

SatelliteGuys Pro
Apr 25, 2006
794
0
Near Asheville NC
I am still strongly considering this approach, given the fact I don't have any polarotor control on my FTA receiver boxes. However, all this talk about 13v and 18v kind of rattles me.

It occurs to me also that I havent' seen any shootout or comparison review of Regular feedhorns and Duals.

I'm counting on you guys, because I certainly don't know enough about it.

I don't want to either underpower or burn something out.

Long ago in the days of analog C/KU band, the receiver sent 18-20 volts to the LNB for power. The LNB specs were usually 15-24 volts, and polarity was selected by a servomotor system. A system was developed with later LNB's that the feedhorn was coupled with the LNB to create the LNBF. A scheme was developed where the polarity was changed by a choice of two different voltages sent to the LNBF...13-14 volts for the vertical polarity, and 17-18 volts for horizontal. Since these LNBF's needed to be made inexpensively, and the majority of them were made for big wide signals, corners were cut in the linear gain and stability areas. The local oscillator stability usually isn't any better than 2 Mhz on most of the cheap LNBF's, and you sometimes don't see this specification in ad slicks. This causes a problem with narrow bandwidth signals where the drift in the oscillator can drag the desired signal right out of the passband, especially with receivers that don't have a good working AFC. It seems that noise figure is the "selling point" specification, when for FTA use the LO stability is a more important attribute. To get this stability (as well as good linear gain) some have went back to the use of commercial single polarity LNB's. With the vast majority of today's receivers, servo polarity control isn't an option, so orthomode feeds with a seperate LNB for each polarity is used. This way one can use as good an LNB set as their pocketbook can afford (good ones are quite expensive) and still be able to configure an arrangement where the receiver can control the polarity with voltage. Since these LNB's like to be powered with ~18 volts, power inserters are used to power the LNB's so that they get a constant voltage. I use a dual orthomode feed with 2 C and 2 KU LNB's. A 4x4 DTV multiswitch is used so that the receiver thinks it is connected to a voltage polarity switching LNBF system. Power inserters are installed just after the switch and it powers all 4 lines going to the 4 LNB's at the feed. With this type system, if power inserters aren't used, when the vertical polarity is selected the receiver is only sending 13-14 volts to the LNB, and this under-voltage can cause anything from erratic operation to no operation at all, and "could" cause premature failure of the LNB due to heat created from excessive current draw. And if a dual system such as mine is used, all 4 LNB's are being powered at once, and this could cause power supply failure in the receiver. The power inserters take the strain off several parts of the system.
 

gabshere

SatelliteGuys Pro
Aug 20, 2006
3,720
21
Rison , Arkansas
if power inserters aren't used, when the vertical polarity is selected the receiver is only sending 13-14 volts to the LNB, and this under-voltage can cause anything from erratic operation to no operation at all, and "could" cause premature failure of the LNB

this was what i understood failure prematurely or erratic signal.... now when you place a high end ( costly) lnb say $100 or more , thats not what you want to occur
 

Lone Cloud

SatelliteGuys Pro
May 23, 2008
701
18
Thanks AC. I wish I knew what a lot of that meant.

If I understand you, you have basically 4 lnbs attached to your feedhorn, 2 for C and 2 for Ku. That sounds efficient. I have basically decided to go with a one meter (Winegard, Invacom) Ku dish to one HD receiver, and my big Birdview solid dish (lnb to be determined) connected to another HD receiver.

I have a home theater receiver that switches between HDMI inputs easily, so that part is easy.

I think you are saying that if I, for example, just ran a disecq switch and had horizontal polarity at position 1 and vertical at 2, something would be powered wrong and that could result in poor signal and lower lnb life.

Do you know of a diagram I could find for hooking up this C-Band system? Where do I find one of these power inserters and how do I hook it up?

Thanks again.
 

ACRadio

SatelliteGuys Pro
Apr 25, 2006
794
0
Near Asheville NC
I'm not much of an artist but here it is. This is for a C band only setup so only one of the Pico Macom's are used...it will power 2 lines.
 

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Lone Cloud

SatelliteGuys Pro
May 23, 2008
701
18
Thanks AC. I haven't responded because I'm looking into the items you drew (pico macom, 3/4) and trying to figure out where they would go and how.
 

stogie5150

Crazed Cajun Rebel
Jan 7, 2007
3,819
46
Slidell,LA
Okay, this is gonna sound funny to you veterans, but how in goodness's name do I bolt the LNB's to the flanges? Which way is right? Do the probes have to match? Obviously the vertical isn't, it will be 90 degrees. does it matter?

Its finally dried up to the point I can walk around the Para without rubber knee boots, so I am gonna have a crack at that dual today, sometime.
 
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