Loosing Channels above 12207V

Kenny Powers

I have a Quad LNB only using 3 o/p, I have a twin combo tuner in one room and a single combo in the other.

When I switch on the single tuner which is closer to the dish I loose Sky News and another couple of channels above 12207V (CNN, Pick and a few music channels) when I switch it off they come back. The single tuner has no issue.

I have checked all connections and replaced the LNB with a known good one still no change.

I also checked the twin tuner on another dish and it works fine.

After all that I put the old LNB back on now I can't get any of the above channels even if the other tuner is off. (It's possible I need to adjust the dish after messing with the LNB) although the single combo box can still get all channel's.

All other channels are unaffected.


Any advice am I missing something here?

Technofobe

Kenny Powers wrote: »

I have a Quad LNB only using 3 o/p, I have a twin combo tuner in one room and a single combo in the other.

When I switch on the single tuner which is closer to the dish I loose Sky News and another couple of channels above 12207V (CNN, Pick and a few music channels) when I switch it off they come back. The single tuner has no issue.

I have checked all connections and replaced the LNB with a known good one still no change.

I also checked the twin tuner on another dish and it works fine.

After all that I put the old LNB back on now I can't get any of the above channels even if the other tuner is off. (It's possible I need to adjust the dish after messing with the LNB) although the single combo box can still get all channel's.

All other channels are unaffected.


Any advice am I missing something here?

If you move the single tuner box to where your twin tuner box is and check the signal quality for both feeds on one of the affected channels see if there is any reduction in quality on one of the 2 sat feeds

Kenny Powers

Technofobe wrote: »

If you move the single tuner box to where your twin tuner box is and check the signal quality for both feeds on one of the affected channels see if there is any reduction in quality on one of the 2 sat feeds

Thanks man I tried that but its an amiko mini combo everything always says 90 on it. The TV has a sat tuner in it that can pick them up, could be a case the signal is weak and the tuner isn't as sensitive and can't get a lock, that doesn't explain why its OK when the other one is switced off.

Technofobe

Kenny Powers wrote: »

Thanks man I tried that but its an amiko mini combo everything always says 90 on it. The TV has a sat tuner in it that can pick them up, could be a case the signal is weak and the tuner isn't as sensitive and can't get a lock, that doesn't explain why its OK when the other one is switced off.

is the cable to the twin tuner the mini shotgun cable
Or 2 single seperate cables

Kenny Powers

Technofobe wrote: »

is the cable to the twin tuner the mini shotgun cable
Or 2 single seperate cables

2 separate ct100 cables with cablecon compression f connectors on both ends.

Technofobe

Kenny Powers wrote: »

I have a Quad LNB only using 3 o/p, I have a twin combo tuner in one room and a single combo in the other.

When I switch on the single tuner which is closer to the dish I loose Sky News and another couple of channels above 12207V (CNN, Pick and a few music channels) when I switch it off they come back. The single tuner has no issue.

I have checked all connections and replaced the LNB with a known good one still no change.

I also checked the twin tuner on another dish and it works fine.

After all that I put the old LNB back on now I can't get any of the above channels even if the other tuner is off. (It's possible I need to adjust the dish after messing with the LNB) although the single combo box can still get all channel's.

All other channels are unaffected.


Any advice am I missing something here?

Isint there some kind of adjustment on a sky lnb when you rotate it left or right a bit are there some markings on it to make it a bit more sensitive as the sky dishes are oblong
is your dish a sky one

http://www.satcure.co.uk/tech/LNB_skew.htm

May only be relevant to having moved the lnb and now getting no signal

Thurston?

Technofobe wrote: »

Isint there some kind of adjustment on a sky lnb when you rotate it left or right a bit are there some markings on it to make it a bit more sensitive as the sky dishes are oblong

Skew applies to all reception of linearly polarised signals, not just Sky dishes. It's to do with your position on Earth, relative to the position of the satellite: the aerial probes in the LNB need to be aligned in the same plane as the radio waves from the satellite, for optimum reception.

Technofobe

Thurston? wrote: »

Skew applies to all reception of linearly polarised signals, not just Sky dishes. It's to do with your position on Earth, relative to the position of the satellite: the aerial probes in the LNB need to be aligned in the same plane as the radio waves from the satellite, for optimum reception.

Thanks

Thurston?

Kenny Powers wrote: »

I have a Quad LNB only using 3 o/p, I have a twin combo tuner in one room and a single combo in the other.

When I switch on the single tuner which is closer to the dish I loose Sky News and another couple of channels above 12207V (CNN, Pick and a few music channels) when I switch it off they come back. The single tuner has no issue.

I have checked all connections and replaced the LNB with a known good one still no change.

I also checked the twin tuner on another dish and it works fine.

After all that I put the old LNB back on now I can't get any of the above channels even if the other tuner is off. (It's possible I need to adjust the dish after messing with the LNB) although the single combo box can still get all channel's.

I wonder can switching on the LNB outputs connected to the twin single tuner receiver, add extra electrical noise to the other ones? Might be enough to scupper an already poor signal, due to a badly aligned or undersized dish.

winston_1

Sounds like the single tuner combo is generating interference/oscillating and sending it up the cable to the LNB.

Thurlston2 sky dishes are elliptical not oblong.

kyeev

Hmm, I'm having a similar problem with a quad LNB and 1 metre dish.

Empty cable on connection 1
Freesat box A on 2
Freesat box B on 3
Freesat TV on connection 4

2 and 4 are working well.
Getting about 65-75% quality.
But I'm getting no signal to freesat box on 3.

Have checked freesat box B on connection 2 and it gets 75% so box B is okay.
If I skew the LNB a fair bit past 15 degrees, I get box B working on connection 3, but I lose 2 and 4 signal?

I thought once the LNB is tuned into satellite, all the cables received the same signal?

Do I need to get signal quality up to 90% to sort this out?

Thurston?

kyeev wrote: »

I'm having a similar problem with a quad LNB and 1 metre dish.

... If I skew the LNB a fair bit past 15 degrees, I get box B working on connection 3, but I lose 2 and 4 signal?

I thought once the LNB is tuned into satellite, all the cables received the same signal?

I'd imagine the signal would vary slightly across the LNB outputs.

So this LNB is at the prime focus of a 1m dish pointing at 28 degrees east, & you're in Ireland?

Too much signal could be your problem.

kyeev

Thurston? wrote: »

I'd imagine the signal would vary slightly across the LNB outputs.

So this LNB is at the prime focus of a 1m dish pointing at 28 degrees east, & you're in Ireland?

Too much signal could be your problem.

Yeah, in Ireland.
I wouldn't say its prime focus cos I haven't bothered to get out my Satellite finder.
I just do it by freesat signal on the TV.

I'm getting about 65% on Astra and 67% on Eutelsat on TV.
And freesat box A says 75% (as does box B when on connection 2)

Incidently, Freesat box B on connection 3 was working up until 2 or 3 nights ago.
Then went dead.
I cut off a couple of inches of cable and reconnected in case it was rain water but still no good

Thurston?

kyeev wrote: »

Yeah, in Ireland.
I wouldn't say its prime focus cos I haven't bothered to get out my Satellite finder.

By 'prime focus', I mean is the LNB at the actual focal point of the dish, as opposed to being an offset LNB in a multi-LNB setup. There's no need for all the gain of a 1 metre dish for reception from 28 east in Ireland.

Try attenuating the signal some way.

kyeev

Thurston? wrote: »

By 'prime focus', I mean is the LNB at the actual focal point of the dish, as opposed to being an offset LNB in a multi-LNB setup. There's no need for all the gain of a 1 metre dish for reception from 28 east in Ireland.

Try attenuating the signal some way.

Okay, I get you. Yes its at the actual focal point, not offset.

Actually I just checked, its an 80cm dish (not 1 metre as I said).
I noticed rain fade on other peoples sky dishes, thats why I went with the bigger dish.

Thurston?

kyeev wrote: »

... I'm getting no signal to freesat box on 3.

Have checked freesat box B on connection 2 and it gets 75% so box B is okay.
If I skew the LNB a fair bit past 15 degrees, I get box B working on connection 3, but I lose 2 and 4 signal?

With the LNB properly skewed, did you check channels from both polarisations, vertical & horizontal, from connection 3? (E.g. Channel 4 for H., Channel 4 +1 for V.)

kyeev

I'll try that and see what happens