helps needed please:(((( possible interference

[mike1]

Can you list some channels with issues?
Is the motor faulty or coax cable not shielded? (High quality copper core)
Have you tried another set top box?
Also turned off DECT base station phone? / WIFI

 

[anto@]

Thank you i Will post some photos later

Anyway what can i do to solve this problem?

Thank you best regards

from a friend of mine we solved in this way, behind the dish there is a telephone BTS that disturbs a certain frequency

 

[Terryl]

Is the system properly grounded?? If the coax is not correctly grounded then you can have direct RFI intrusion to the system.

A simple satellite rated ground block and a good ground may solve a lot of problems.

 

[4Himdj]

Hello, here's the photos I need to make some premises:
1) you can see a lnb without cap in one of the photo. I want to clarify that I've tried 3 different lnb with the same result
2) I'm not very good with some aspects like "shielding". All i know is that I've a "CAVEL DG" cable for all my system. I live at 8th floor and the dish is on the roof, 2 floor above
3) I've switched off both cordless telephone and wifi roouter with no result.
4) I've connected the satellite meter directly to the lnb so I don't understand why i should try another receiver besides my ax hd 61, or another motor (my question is not "polemical", I'm just asking to understand)
5) I put some frequencies affect from this problem (after checking I can say frequencies are between 11400 and 11550)
16east
11471H /11471V / 11512 H NO SIGNAL (before at least 12db)
11512V from 0 to 7db (before at least 14db)
11554 H has 15db

13east
11488 H 9,8db (before at least 13db)
11508 V NO SIGNAL

5West
11509 H from 0 to 10db (before at least 15db)

27,5west
11495 V NO SIGNAL (before at least 7db)








grazie a tutti (thank you everybody)
best regards

 

[Channel Hopper]

If your installation is on the roof of a 10 storey building you could find interference from almost any direction, up to a range of 20kms, depending on the local topography

Have you looked on local maps to check the existence of towers, possibly point to point transmission routes. Do you have any industrial sites nearby, an airport (or military establishment) or are you in between two major built ap areas ?

 

[4Himdj]

hello i live in rome post code 00157
dish it's there since long times, so something has been "activated" now (the problem started one week ago)
yes there's military estabilishment i think 2km near to me.

do you think there is something i can do?

thank you

 

[anto@]

since the problem is on a frequency value ranging from 11450 to 11600 over the whole polar arc it means that it is a transmission that enters you in the direct lnb, so you can change all the lnb you want but the problem will remain for you always, the only solution is to move the dish to a point hidden from interference behind a wall or something else, you can do a test try to put yourself next to the dish and move slightly in order to shield this interference and another person in the house that controls that the signals change in value

 

[ozumo]

If the interference is 1700-1850MHz an LNB with different local oscillator may work. How about an additional offset wideband LNB?

11450MHz to 11600MHz:
Universal LNB 9750/10600 LO = 1700-1850MHz
Wideband LNB 10400 LO = 1050-1200MHz

With the wideband LNB the frequencies affected by the interference will be different to the universal LNB. If the interference is 11450-11600MHz then this solution won't work.

 

[jeallen01]

since the problem is on a frequency value ranging from 11450 to 11600 over the whole polar arc it means that it is a transmission that enters you in the direct lnb, so you can change all the lnb you want but the problem will remain for you always, the only solution is to move the dish to a point hidden from interference behind a wall or something else, you can do a test try to put yourself next to the dish and move slightly in order to shield this interference and another person in the house that controls that the signals change in value

And also, fit a metal shield (like a used baked bean can with a suitably sized hole in the bottom, with the can connected to either the shield on the cable, or to a real local ground !) around the LNB - I can't point to a relevant thread/post but I'm sure this was mentioned somewhere on the forum in times past, so maybe someone else can identify a relevant thread?

 

[Channel Hopper]

I think the problem is not down to the satellite equipment on the roof, but a local source of interference breaking through the outer braid of the cable.

 

[4Himdj]

hello everybody
first of all thank you for all the suggestions and tips.
I went to the roof and I've made some test. It's an inteference for sure.

I gain signal if I stay behind the motor or If i put a steel tray near to the lnb, but it's very very unstable and i loose signal if I make minimum movement. this steel tray decrease signal on all the other tp's anyway

13east
11488 h the signal increase if I stay on the left behind the motor, crosswise. from 9,8 to 13 db. with steel tray near to the lnb i can go to 14db but I need to put in a way completely different from 16 east

16east
11471 v and 11512 v I can catch the tp's (very fringe and unstable) if i put the steel tray in a certain way on the right near to the lnb

Do you think I can ask the 2 person that lives 2 floor above me if they bought something new in the last 10 days, related to cordless or wi-fi? or it has no sense?
In live in a big group of building all around me, at least 500 person...

thank you for your kind help and please share any other suggestion.

best regards

 

[Channel Hopper]

Possibly, but I would go on the roof and have a look in all directions for any new towers put on apartment blocks nearby.

It is gong to be difficult to diagnose without an wide band analyser of some description and a short range antenna working at IF frequencies.

 

[Manikm909]

Hello, here's the photos I need to make some premises:
1) you can see a lnb without cap in one of the photo. I want to clarify that I've tried 3 different lnb with the same result
2) I'm not very good with some aspects like "shielding". All i know is that I've a "CAVEL DG" cable for all my system. I live at 8th floor and the dish is on the roof, 2 floor above
3) I've switched off both cordless telephone and wifi roouter with no result.
4) I've connected the satellite meter directly to the lnb so I don't understand why i should try another receiver besides my ax hd 61, or another motor (my question is not "polemical", I'm just asking to understand)
5) I put some frequencies affect from this problem (after checking I can say frequencies are between 11400 and 11550)
16east
11471H /11471V / 11512 H NO SIGNAL (before at least 12db)
11512V from 0 to 7db (before at least 14db)
11554 H has 15db

13east
11488 H 9,8db (before at least 13db)
11508 V NO SIGNAL

5West
11509 H from 0 to 10db (before at least 15db)

27,5west
11495 V NO SIGNAL (before at least 7db)








grazie a tutti (thank you everybody)
best regards

nice dish...Laminas.