Professional help req

**keano** · 13-01-2008

Guys can someone give me some guidance on these Norsat LNB's ?

I am looking at trying to get one for freq 11996.

Now looking at their site it would appear I need the DRO 4000.

Now I understand the letter at the end I need to pick is A this is for 11.70-12.20GHz.

I also understand the noise figure, I presume the lower number the better ?

Its the second number the L.O stability whats this all about ?

Finally how do these connect to the Channel Master feedhorn, if the lnb is square and the feed is round does it require something in the middle ?

Is there anything else I need to know about the norsat/andrews feed combination ?

Thanks

K

**canofan** · 16-01-2008

Hi Keano,
The flange interface is what is making me hesitate about Norsat.
This and the fact that I am not sure how to order one that has voltage switching ( 14 and 18v ).
I know that for applications like ours the LO stability is not so critical.
Remember that the LO stability for INVACOM is only 1 mHZ.
I think a 4506A should do.
This is why I got interested in the invacom QPF-31 using only the linear ports..
But here again the gain figure is just the same as for the universal LNB's: 55db typical compared to the 60 db typical for the Norsat
.
RD100 has the experience and I hope he will help us clear the matter.

**keano** · 16-01-2008

m8 I was hoping RD100 might shed some light on how these work.

Finding info on them is not easy.

There as since yesterday been a increase in power on the H transponders.

I was even able to watch Showsports today without a single glitch in the pouring down rain.

This I can only think is the UK is making its slow way back South.

**michael01707** · 16-01-2008

I also noticed that the horizontals were stronger during the day today, the skies were clear here in London. By the evening I was able to tune into and see 11996 and a few others. I've not had anything from the horizontals since just before christmas during the day. I swapped over the LNBs from Inverto single to Invacom single, only a little improvement. What feedhorn are you using at the moment Keano?

**keano** · 17-01-2008

I am using the CM feedhorn but its not the one that guys on here recommend.
I found the long and narrow feedhorn better.

Something funny is going on with 7.0w at the mo, this morning at 05.30 I was able to pull in all H transponders and watch them perfect even sky news and ten sports ( 11804H ) and it was little raining.

Yet a couple of the V transponders were breaking up

, space toon english and melody tunes broke up and yet these are watchable normally on 110cm at night never mind the 240cm.

Watch this space

19-01-2008

All you do is bolt the norsat lnb to the feedhorn the same as any other c120 lnb, I find nilesat gets strong from 5.30 pm and fades out about 5am and the strongest peak time is about 1am

19-01-2008

Got a photo of your feedhorn???

Originally Posted by keano

I am using the CM feedhorn but its not the one that guys on here recommend.
I found the long and narrow feedhorn better.

Something funny is going on with 7.0w at the mo, this morning at 05.30 I was able to pull in all H transponders and watch them perfect even sky news and ten sports ( 11804H ) and it was little raining.

Yet a couple of the V transponders were breaking up, space toon english and melody tunes broke up and yet these are watchable normally on 110cm at night never mind the 240cm.

Watch this space

**keano** · 19-01-2008

Hi m8,

Starting to wonder if you were on Holiday but take it you've been working all week

I have seen the Norsat 4206A but what gets me is the end is square so how can the andrews feed bolt to it because the feed is round.

Would you go for the 4206A ?

I know I will lose quality on anything over 12.2

Whats canofan on about regarding voltage switching with these ?

You've seen the feed i'm using but will post picture again.

7.0w at the mo is at its strongest its been for the last couple of weeks and yes you're right about the times, I can even pick 11804H at these times.
I can't believe how weak this one is, its like 12% weaker than 11921H.

19-01-2008

Just on my way out will post back later, That is a Andrew circular polarization feedhorn and should not be used at all for linear,

Originally Posted by keano

Hi m8,

Starting to wonder if you were on Holiday but take it you've been working all week

I have seen the Norsat 4206A but what gets me is the end is square so how can the andrews feed bolt to it because the feed is round.

Would you go for the 4206A ?

I know I will lose quality on anything over 12.2

Whats canofan on about regarding voltage switching with these ?

You've seen the feed i'm using but will post picture again.

7.0w at the mo is at its strongest its been for the last couple of weeks and yes you're right about the times, I can even pick 11804H at these times.
I can't believe how weak this one is, its like 12% weaker than 11921H.

**keano** · 20-01-2008

OK found some pictures of a guy in the USA with same setup as to what I might do.

Here are his pictures, he is using the same feedhorn as me.

Only prob is AFAIK they only have the one probe.

**Topper** · 20-01-2008

Originally Posted by keano

OK found some pictures of a guy in the USA with same setup as to what I might do.

But that will not work over here as most of the USA birds are circular polarisation and most of ours are Horizontal and vertical polarisation therefore basing a design on an American system would be unwise unless you were intending moving there

**keano** · 20-01-2008

I understand what you are saying but the bottom line is this feedhorn is giving me 2% better signal on the H beams on 7.0w.

I have tried both feedhorns many times and with both the invacom and the inverto and the circular feed was better

Here is the feedhorn on dish with invacom single, now got a quad there instead.

20-01-2008

That is what i am trying to tell him that is the Andrew 611-6060-17 feedhorn would have been good for use on sirius 1 or thor 1 back in the d2 mac days but now the nearest kusat that could be used for in europe would be w4 russia beam in east europe, You can use that feedhorn on linear but you would loose a few db of signal

Originally Posted by Topper

But that will not work over here as most of the USA birds are circular polarisation and most of ours are Horizontal and vertical polarisation therefore basing a design on an American system would be unwise unless you were intending moving there

20-01-2008

Technically speaking that feed should be worse

Originally Posted by keano

I understand what you are saying but the bottom line is this feedhorn is giving me 2% better signal on the H beams on 7.0w.

I have tried both feedhorns many times and with both the invacom and the inverto and the circular feed was better

Here is the feedhorn on dish with invacom single, now got a quad there instead.

**keano** · 20-01-2008

I'll think I'll just give up the ghost on this one because its like banging my head against a brick wall.

One more time with pictures ( just this second taken ) on the left performs approx 2% better than the right, I have two of the feedhorns on the right and both gave the same results.

20-01-2008

The one on the right on the brown post is the correct linear feedhorn and should be used,

Why do you want to change the lnb any way are you getting signal drop outs in the rain,

Originally Posted by keano

I'll think I'll just give up the ghost on this one because its like banging my head against a brick wall.

One more time with pictures ( just this second taken ) on the left performs approx 2% better than the right, I have two of the feedhorns on the right and both gave the same results.

**keano** · 20-01-2008

I wanted to try something new, so thought I would try the norsat 4106A.

This will hit the range I require.

And yes I know the feed on the post is the one which you are suppose to use but for what ever reason the one on the left performs better even though it is not designed for linear.

If I do get the norsat I will report back with results.

**canofan** · 20-01-2008

@keano,

I gathered the following info about the Norsat LNB. I could provide the links if interested.

"The lack of voltage controlled polarity switching limits the practical application of these LNBs to one satellite-one polarity installations.

Unlike the newer lnb's and they should actually be called lnbf's this lnb is usually made to pick up only h or v and a polorotor changes the polarity..... so add it to a feedhorn and the motor switches the polarity

the newer lnbfs allow voltage switching usually via coax this one doesn't

FTA receivers intended for the consumer market are designed to work with LNBs which automatically switch between horizontal and vertical polarity signals. This switching is controlled by the level of DC voltage the receiver uses to power the LNB, which varies between 13 and 18 volts.

This Norsat LNB is primarily intended for commercial applications that are dedicated to a single signal satellite and polarity. In these installations polarity adjustment is accomplished by the installer rotating the entire LNB and clamping it down in the LNB holder.

An LNB can see some amount of signal from transponders of both opposing polarities, even without any change in the LNB's polarity adjustment. Attenuation of adjacent signals by polarization can be very effective, but is always less than absolute. The greater the strength of the incoming signals, the more this becomes evident.

If the LNB is aligned to a polarity position between what would be optimal for one polarity or the other, the difference between the signals is diminished.

If you try rotating the Norsat for optimal performance on one polarity. You should see a very noticeable degradation in performance on transponders of the opposite polarity."

To me using the Norsat with a polar rotor is a complication that I would want to avoid as my dreambox cannot command the rotor.

Does this also knock it on the head for you?

**keano** · 20-01-2008

Interesting read.

Thanks m8.

20-01-2008

Back in the spring i brought a new digi cam and still have some pics on my pc from it here is a 2.2m dish (dish on the left) with a norsat c120 lnb which i replaced for 11634 v from 16'e which are feeds to transmitter sites then at the site they are converted to DVB-T ,

_http://img260.imageshack.us/my.php?image=s8000956sw2.jpg

Also we also use 11659v some times but only use 11659v if we are in scotland as 11659v is the scottish dvb-t transimtter feed

Originally Posted by canofan

@keano,

I gathered the following info about the Norsat LNB. I could provide the links if interested.

"The lack of voltage controlled polarity switching limits the practical application of these LNBs to one satellite-one polarity installations.

Unlike the newer lnb's and they should actually be called lnbf's this lnb is usually made to pick up only h or v and a polorotor changes the polarity..... so add it to a feedhorn and the motor switches the polarity

the newer lnbfs allow voltage switching usually via coax this one doesn't

FTA receivers intended for the consumer market are designed to work with LNBs which automatically switch between horizontal and vertical polarity signals. This switching is controlled by the level of DC voltage the receiver uses to power the LNB, which varies between 13 and 18 volts.

This Norsat LNB is primarily intended for commercial applications that are dedicated to a single signal satellite and polarity. In these installations polarity adjustment is accomplished by the installer rotating the entire LNB and clamping it down in the LNB holder.

An LNB can see some amount of signal from transponders of both opposing polarities, even without any change in the LNB's polarity adjustment. Attenuation of adjacent signals by polarization can be very effective, but is always less than absolute. The greater the strength of the incoming signals, the more this becomes evident.

If the LNB is aligned to a polarity position between what would be optimal for one polarity or the other, the difference between the signals is diminished.

If you try rotating the Norsat for optimal performance on one polarity. You should see a very noticeable degradation in performance on transponders of the opposite polarity."

To me using the Norsat with a polar rotor is a complication that I would want to avoid as my dreambox cannot command the rotor.

Does this also knock it on the head for you?

**keano** · 21-01-2008

Cheers m8, good pic.

I like the dish on the right

**canofan** · 21-01-2008

I am trying to imagine a polarotor actuator. It would be triggered by the 14/18 volt of the v/h diseqc.
Does such a contraption exist?

**Llew** · 21-01-2008

Nothing to do with DiseqC. A polarotor is a servo motor operated by the skew output of a receiver with this facility. (My Echostar AD3000ip for instance).

It's a discrete uniit that is connected ahead of the LNB to change the polarity.

Preferred the magnetic polariser myself when I had that setup.

Llew

22-01-2008

The dish on the right is not for satellite it is a 3.7m andrew terrestrial microwave antenna

Originally Posted by keano

Cheers m8, good pic.

I like the dish on the right

22-01-2008

I miss not having a polarizer wish they still made digital receivers with it and 36v,

Originally Posted by Llew

Nothing to do with DiseqC. A polarotor is a servo motor operated by the skew output of a receiver with this facility. (My Echostar AD3000ip for instance).

It's a discrete uniit that is connected ahead of the LNB to change the polarity.

Preferred the magnetic polariser myself when I had that setup.

Llew

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Professional help req Information exchange on LNBs, Single satellite, motorised and multi-satellite systems. DiSEqC switches, positioners, motors, actuators, dish-alignment etc.

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