LNB & Feedhorn Question

radical

Member
Joined
Apr 5, 2008
Messages
4
Reaction score
0
Points
0
Age
53
My Satellite Setup
150 Cm Focal Nokia Dish.
Topfield TF-7700 HSCI.
LNB: Invacom C120 single.
Feedhorn: SMW-XM 140
Cables: Edison >120
My Location
Sweden
Hi,

I have some problems with the reception on my motorise sat-system, after a while of watching..the picture jumps out of signal.

It seems to me there is some interference between the V&H signals?

I have the Invacom Single SNF-031 C120 LNB combined with an older SMW XM-500 Feedhorn.

Does anyone know if these combination could be the cause of this problem?

Thanks
 

Llew

cerca trova...
Staff member
Joined
Jan 1, 2000
Messages
15,641
Reaction score
3,823
Points
113
Age
79
My Satellite Setup
Triple Dragon, Dreambox 8000, Echostar AD3000ip, TBS6522,6925,6983 PCie cards.
Gibertini 1.25m motorised dish driven by the AD3000, with either Inverto BU Quad or Norsat / XMW Ka LNBs . SMW 1.05m + 3 other dishes. Speccy: Promax HD Ranger+
My Location
The Flatlands of East Anglia
Thh XM-500 is a circular feedhorn ideally mated with an SMW dish. This is almost certainly why you are experiencing polarisation problems.

How have you coupled it to your Invacom?

Llew
 

radical

Member
Joined
Apr 5, 2008
Messages
4
Reaction score
0
Points
0
Age
53
My Satellite Setup
150 Cm Focal Nokia Dish.
Topfield TF-7700 HSCI.
LNB: Invacom C120 single.
Feedhorn: SMW-XM 140
Cables: Edison >120
My Location
Sweden
Llew said:
Thh XM-500 is a circular feedhorn ideally mated with an SMW dish. This is almost certainly why you are experiencing polarisation problems.

How have you coupled it to your Invacom?

Llew



Yes the XM-500 feedhorn is circular and for focal dishes, but so is the Invacom SNF 031 Single LNB.

The flange is C120 and it is fitted to either the older XM-500 or the never SMW XM 140 without problem.

What i get out from the spec of the feedhorns F/D. there shouldn't be a problem really?

What i don't get is what combination of feedhorns and LNB are compatible then?

The Invacoms feedhorn are to thin in diameter, but of course a handyman like me could always fix that :)

I just want the best reception for all channels

Any recommendations of compability?

Thanks
 

Llew

cerca trova...
Staff member
Joined
Jan 1, 2000
Messages
15,641
Reaction score
3,823
Points
113
Age
79
My Satellite Setup
Triple Dragon, Dreambox 8000, Echostar AD3000ip, TBS6522,6925,6983 PCie cards.
Gibertini 1.25m motorised dish driven by the AD3000, with either Inverto BU Quad or Norsat / XMW Ka LNBs . SMW 1.05m + 3 other dishes. Speccy: Promax HD Ranger+
My Location
The Flatlands of East Anglia
So you had no problem fitting the feedhorn to the Invacom? I found my XM-604 4-hole fixing didn't align with the Invacom perfectly, and had to leave one screw out. Still a good seal though on the O-ring.

Don't know the best feedhorn for your PF dish, only have offset ones.
 

Robbo

Retired Mod
Joined
May 17, 2007
Messages
6,424
Reaction score
5
Points
38
Age
54
Website
www.mbcsatellites.co.uk
My Satellite Setup
TM6800HD, TM1000, TM600 Linux,TM2200 motor, Channel Master 1.2m motorised, TD110 dish Meter=Satlook Micro+G2 NIT
My Location
Gravesend,Kent,UK
Your XM-500 hasn't got the integrated RHC/LHC integrated depolariser by any chance, as I imagine this would affect performance?

_http://www.smw.se/res/pdf/feedhorn1.pdf

Robbo:)
 

radical

Member
Joined
Apr 5, 2008
Messages
4
Reaction score
0
Points
0
Age
53
My Satellite Setup
150 Cm Focal Nokia Dish.
Topfield TF-7700 HSCI.
LNB: Invacom C120 single.
Feedhorn: SMW-XM 140
Cables: Edison >120
My Location
Sweden
Robbo71 said:
Your XM-500 hasn't got the integrated RHC/LHC integrated depolariser by any chance, as I imagine this would affect performance?

_http://www.smw.se/res/pdf/feedhorn1.pdf

Robbo:)

Ok thanks all satpros.
I was thinking of fitting the XM-140 with the Invacom C120 SNF-031.

What LNB,s would be better then Invacom SNF 031 if.. i'm after a better performance for all freq ?

My current dish gives me about 38 Eirp in KU-band from where i live.If i could get it better in performance with a better feedhorn and LNB it would always be appreciated.The F/D on my dish is 0.4. Amplifing 11.3Ghz is 43,3dbi.

The offset dishes is said to get better performance then focal ones. How much difference % are e talking about here with the same size dish?

Is a wider feedhorn like invacoms give better reception&performance if fitted correctly then the XM-140?

I thought i might get it to fit my feedhornholder with some special made adapter.

Thanks
 
Top