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Discussion Starter #1
Hello: Maybe someone can help me out. I'm totally new. Here the problem. I've got a 1.9m motorize dish feeding a skystar-HD2, with a BSC-621 dual band LNB (5150,10750) I'm located in southern Ontario. For example I can receive on AMC-1 PBS 4091 V 14029, but nothing else tunes in. I would think 3740V29270 or 3972V14800 right "next door" should tune in. I'm trying to receive both C and Ku FTA signals.

Is having the dielectric plate install a problem?
Does this LNB only receive C Band Vertical / Ku Horizontal signals? (Since the probes are 90 degrees to each other
Is this LNB a "lemon"
Is the dish too small?
Is this just an alignment issue?

TIA Andrew
 

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The dielectric plate is used to receive circular signals. All the KU are linear so remove the plate. Most Cband are linear as well.
I don't do C band but my understanding is that 1.9 meter dish is the bare minimum for reasonable reception.
 

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Discussion Starter #3
I'll concentrate on Ku. Remove the dielectric plate. Well see what happens from here. I'm also guessing, If I remember the Ku "probe" is horizontal that I'm limited to horizontal polarity. don't suppose that a 2.4m dish would make much of a difference? Thanks
 

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I have no problem receiving most signals with 7.5' dish in WNY...
What do you mean, is only H polarity?
What type of feed do you have on the dish?
Or are we talkin about two different antennas for C and Ku??
 

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Discussion Starter #5
The BSC621 is a dual band C/Ku LNB with a 22k switch

Inside the "horn" behind the dielectric plate there are two antennas. If I remember right, the C Band is vertical nearer the front and the Ku antenna is further back and horizontal. I really scratching my head as too why I'm getting so few signals.
For example on AMC-1 I can only get PBS.C Band which is vertical Being a rookie, I was wondering whether the antenna placement within the LNB is limiting the ability to receive signals of different polarity. But I've managed to get the "test pattern" on Galaxy-17 ABC news one which is vertical on Ku.
So, I'm really scratching my head as too why I'm getting so few channels. i.8 meters translates to about 6 feet.
 

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There may be some confusion.
See the manual online:
http://www.dmsiusa.com/documents/621-manual.pdf

The BSC-621 switches polarization electronically.
When the receiver is set to Horizontal, the receiver outputs ~ 18VDC,
When it is set to Vertical, the receiver outputs ~ 14VDC.
The BSC 621 switches polarization based on that voltage it is seeing from the receiver.
It also switches Frequency bands using a 22 KHz tone, so make sure to setup the receiver's LNB settings appropriately.

Definitely remove the di-electric plate, and save it for a rainy day for now, as it will degrade reception on Linear Polarised signals somewhat. It is not the best feedhorn to begin with...

Also keep in mind though it is a dual band feedhorn, you will find that ya probably won't be able to 'peak' C Band reception and Ku Band reception at the same time very well, no matter how much you fuss with it. So peak it for one or the other, whatever is more important to you. Ensure the focal length is set and the feed is properly centered.

Read through these pages thoroughly also:
http://www.geo-orbit.org/sizepgs/tuningp2.html
 

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Discussion Starter #7
If the BSC 621 is causing some / most of my problems. Is there a better LNB you would recommend? I hate to say money is no object, but at the moment I've got a large bird bath that won't hold water :) Or should I bite the bullet and invest in a larger bird bath also? Out of curiosity, you said your dish is 7.5 feet what about the rest of your setup? My eventual goal is to integrate this into mythtv. Andrew
 

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I've got a 1.9m motorize dish feeding a skystar-HD2, with a BSC-621 dual band LNB (5150,10750) I
#1 limitation is the dish size. Too small of a dish will see too much of the sky at once for CBAND, resulting in adjacent satellite interference that nothing you do can ever overcome.
#2 limitation would be the BSC style lnbf.

I am sure you could get one of those to work OK on a large antenna, like say 10 to 12 feet. But no way on a small antenna. I would take what I could get for now and not kill myself putting all sorts of money in to. Use it to get used to using a satellite system in general. Meanwhile keep your eyes peeled for a larger antenna and save your money to beef that up should something become available to you. If I had my way, I would put up the 10 ft fiberglass I have, but some battles are just better off not being fought;)
I wouldn't go less than 8ft for CBAND around here.

You could also keep the 1.9M for Ku service (should be fine for Ku) and dedicate a future large antenna for CBAND.

I would expect to have less trouble with some of the stronger DVB-S signals, than the DVB-S2 signals.
For DVB-S2 signals everything needs to be "Spot on"

So, back to your original question... You should be able to get signals on both polarizations though, provided the signal is good enough on the transponders your
looking for. For 103W, you confirmed the PBS mux on Vertical, that's a DVB-S QPSK signal not very hard to pick up. Try the ION mux at 3840 H 26680.
It is also DVB-S QPSK and should be just as easy to find.
 

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If you are going to use cheap, Chinese made lnbs, I would buy 3-4 from different suppliers and test all of them. At least 1 will work reliably!
 
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