LNB and scalar assembly

[larrchev]

Hello
I just bought a DMX741U lnb with a scalar ring.It came from WS international and they didn't include assembly or setup instructions.I am familiar with DSS and ku band assembly but I am new to C-band.I'm using a rotor with my offset dish and I need to know how far I'm supposed to lock the scalar ring on the lnb.HELP!
Thanks.

 

[1beertap]

I have the same LNBF as you. Just go to this link below for instructions to install:

http://www.wsidigital.com/dmx-lnb/DMX741 INSTALL MANUAL.pdf

 

[Long Hair]

if your using a offset dish you might not want to use that scalar ring. I've read
here on this forum that you will get a better signal without it.

 

[larrchev]

thanks beertap.I tried it but It doesn't tell me much about offset.I would prefer a diagram to start off.

 

[larrchev]

Thanks longhair,will try both ways and see.

 

[Anole]

What sort of offset dish are you using?
Size and brand.

There are a number of threads on the forum suggesting a conical scalar is preferred for many offset dishes.
However, there was also a post for fine-tuning a flat scalar, but either way the adjustment is critical.

 

[larrchev]

Picking up dish Wed,will let you know.

 

[nycrich]

I have a DMX741U motorized from 12.5W to 139W getting most of the C & Ku sats. The scalar that came with it is designed mainly for prime focus dishes. Signals would be marginal on strong sats, and trying to get C & Ku together would require lots of experimentation and modding if you want to continue using the scalar that came with it.
Best would be to use a conical scalar ring with the lnb on your offset dish. Manually move your dish to a strong sat depending on your location like 87W that gives strong C and Ku signals for tweaking.
The dielectric plate (small brown fiberglass piece) is used for reception of circular polarizations, sats like NSS806. You cannot have this in the lnb for linear sats because the signals will be degraded.
I have attached pics using the same lnb, but with a prime focus dish. The O degreee on the lnb should generally be orientated downwards and set to 0 at your true south. Remember this lnb have a diseqc switch built in. Therefore you have to set Port1 "on" for c band, and Port 2 "on" for Ku band signals.

 

[larrchev]

Hi Nycrich
I'm using a 36" multistar offset dish and conical scalar ring.So I set the zero on the back of the lnb at bottom south and on the receiver set the disq settings at port one for c band and port 2 for ku?I also use a hh90 rotor,will this change anything?

 

[greenguy]

what i dont like about the instuctions on the link a member posted is that they dont say anythign about centering the lnb.

I have a DMX741U motorized from 12.5W to 139W getting most of the C & Ku sats.

off topic. . .


what lengh jack are you usin to gettin a full 126 degrees of rotation?

do you hav any pics of you dish?

 

[larrchev]

I have a DMX741U motorized from 12.5W to 139W getting most of the C & Ku sats. The scalar that came with it is designed mainly for prime focus dishes. Signals would be marginal on strong sats, and trying to get C & Ku together would require lots of experimentation and modding if you want to continue using the scalar that came with it.
Best would be to use a conical scalar ring with the lnb on your offset dish. Manually move your dish to a strong sat depending on your location like 87W that gives strong C and Ku signals for tweaking.
The dielectric plate (small brown fiberglass piece) is used for reception of circular polarizations, sats like NSS806. You cannot have this in the lnb for linear sats because the signals will be degraded.
I have attached pics using the same lnb, but with a prime focus dish. The O degreee on the lnb should generally be orientated downwards and set to 0 at your true south. Remember this lnb have a diseqc switch built in. Therefore you have to set Port1 "on" for c band, and Port 2 "on" for Ku band signals.

I'm using a Fortec Lifetime Ultra and a 36" Multistar dish.The DMX741U switch says it's freq is 10650.Will it pick up 10750 ku?I've tried everything you suggested,still no ku signal.I do get 95% signal but no quality.I tried an external disque switch,still nothing.

 

[Lak7]

The DMX741U switch says it's freq is 10650

It says 10650 or 10600?

Will it pick up 10750 ku?

As long as you enter the correct LNB L.O. then you are good.

I'd Start with C Band first, don't even connect to the Ku LNB.
The instruction should tell you which Diseqc Port to use for C and Ku.
I "think" it's Diseqc Port 1 to c Band and Port 2 for Ku

 

[nycrich]

Hi Nycrich
I'm using a 36" multistar offset dish and conical scalar ring.So I set the zero on the back of the lnb at bottom south and on the receiver set the disq settings at port one for c band and port 2 for ku?I also use a hh90 rotor,will this change anything?

Make sure that C band is set up as
Standard-5150Mhz
Disecq settings-Port 1 (or "A")

Ku settings
Universal- Low 9750
High 10600
Disecq settings- Port 2 (or "B")

Have jumper coax from ku out on lnb to in on C band
Then have "To recv" on lnb to your receiver.

Need to set up the declination angle for your HH90/Dish (very important).

 

[nycrich]

Hi Nycrich
I'm using a 36" multistar offset dish and conical scalar ring.So I set the zero on the back of the lnb at bottom south and on the receiver set the disq settings at port one for c band and port 2 for ku?I also use a hh90 rotor,will this change anything?

Sorry I'm reponding to multiple post on this thread, ignore the C band settings. However set up wiring the same as described above. I noticed that if I run coax only from Ku output signal level is weaker. Better to wire through the built in disecq switch as mentioned above, as it seem to have a built in amplifier. I ran 100 ft coax to my receiver.

 

[nycrich]

what i dont like about the instuctions on the link a member posted is that they dont say anythign about centering the lnb.




off topic. . .


what lengh jack are you usin to gettin a full 126 degrees of rotation?

do you hav any pics of you dish?

Using a 6 foot Fortec )(6 panel dish)/ DMX741U lnb/ 24 in motor to a Vbox 3000 to a Coolsat 4000 (until AZBOX Premium Plus arrives).

 

[nycrich]

I'm using a Fortec Lifetime Ultra and a 36" Multistar dish.The DMX741U switch says it's freq is 10650.Will it pick up 10750 ku?I've tried everything you suggested,still no ku signal.I do get 95% signal but no quality.I tried an external disque switch,still nothing.

Better to wire from "Ku output" to "lnb input", then another coax from "to recvr" to your FTA receiver. I get better signals. However depending on your receiver then C band lnb freq is 5150 Standard and the Ku needs to be set as Universal Low 9750 High 10600 (not 10650 or 10750), as this is a universal lnb and not a linear. The port settings under disecq should also be set for C band as the first (Port 1 or A) and Ku second (Port 2 or B).
After setting up receiver, look for a strong Ku sat in your location and verify reception. Then do the same with C band if applicable.

 

[nycrich]

what i dont like about the instuctions on the link a member posted is that they dont say anythign about centering the lnb.




off topic. . .


what lengh jack are you usin to gettin a full 126 degrees of rotation?

do you hav any pics of you dish?

Attached is some pics of the dish, motor , and reception of 15W(MSNBC) and 139W Nothing showing currently on 12.5W when I took the pics.
The first set of pics show the dish/lnb installation looking at 55.5W (Caribvision sig 90). The last set shows dish moved to 139W.

 

[greenguy]

thanks for the pics. . .you really have that jack to the limit

 

[nycrich]

thanks for the pics. . .you really have that jack to the limit

I decided not to go all the way to 139W, because the main transponder is scrambled and the rest of channels are radio. Therefore I gained some lenght on the east limit and stopped at 135W. I really don't look at anything on C band past 129W (I have Dish network for that). As a result I gained a couple inches to use on the east limit (makes a big difference) and the dish does not struggle/bind as before. I usually go only to 15W, as 12.5 W I get those channels on other sats between 15W to 135W.
As I go to the east -west limits it takes small increments on the jack to hit sats, because the curvature of the arc makes them appear closer.
I also use the dielectric insert with good results on C band. I am also lucky to get most of the C-band Brazilian sats( linear).
The only sat that I cannot get on ku from 12.5W to 129W is Satmex at 116W(can get data/internet feed though). My other dedicated 36in dish in the background receives signals on that sat at marginal quality. However I can get almost all the C band transponders on Satmex 113 & 116W.