No signal from a few channels... NASN

PaulBM

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Thought I'd ask in here if anyone else is having problems receiving a signal from a few Sky Digital channels?
One in particular that has recently stopped is North American Sports Network, which we subscribe to.
I've looked at their website and followed their FAQ about checking my signal strength and quality, but they are both apporaching 75%.

The only thing that I don't do is have the telephone line connected, it hasn't been connected for years though. :)

Any ideas what might be the problem?
 

rolfw

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The signal strength indicated in the services menu under system setup is purely for the default transponder, you can check the specific signal strength by going to services, system setup, 01select, manual tuning and typing in the frequency of that transponder.

It may of course be a problem with the digibox, Grundig boxes experience sporadic channel loss when the power supply goes.
 

PaulBM

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Here's what NASN tell us to do in their web site FAQ. This produces a 75% strength and quality reading.

Press Services
Select #4 System Set-up
Press 01 followed by select
Select #2 Default Transponder
Frequency input 11623 (this is the satellite where NASN sits)
Polarisation change V to H using the east - west buttons
Save new settings - press select
Press Backup
Select #6 Signal Test.

I've tested all the channels up to 588, here's the list of our broken channels...

208 Freindly TV
220 Fashion TV
247 Classics TV
417 Nasn
427 Wrestling Channel
588 Information TV

Our sat box is a Panasonic , btw.

No answer from my enquiries to NASN yet, either. :)
 

rolfw

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I bet Sky don't know that they are telling people to change the default transponder, not generally a good idea when the manual tuning does the same thing more quickly and doesn't change any critical settings.

Have you tried what I suggested?
 

rolfw

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Those channels are all on the same transponder, have you by any chance installed a DECT phone recently?
 

twag42

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some of the problem might be that some of these channels are actually on the eurobird satellite and not astra2.i have a skybox also and im not having any problems with these channels.

TWAG
 

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Rolfw, I tried what you suggested and all seemed fine. Then a day or so later I think it was BBC3 gave no signal. A day or so after that NASN went again and BBC3 came back!
We've had no changes to our phones in the house, either. I even connected the skybox to the phoneline for 24 hours, but no joy.
Checking NASN today.... it's working! Too early to check BBC3 and 4 though. :)
Seems to be an intermittent fault, the worst kind. O-st

Thanks for your help anyway.

BTW, what *should* be the default transponder?
 

rolfw

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11.778 V 27,500 2/3 is the correct default tramsponder, the box may well go back to it on its own.

The problem of channel loss can happen with digital wireless phones when one is left near the digibox, it only seems to affect certain frequencies. But if you don't have one, then it won't be that, there can however also be problems with radar detectors in cars.
 

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Thanks. My main concern is that the digibox has an intermittent fault. But, if it does turn out to be interferrence, replacing the box won't help.
Not sure how to proceed now. :)
 

rolfw

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Next step is top borrow a friend's box and try it on your setup, or alternatively take your box to their house, you need to eliminate some possibilities
 

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twag42 said:
some of the problem might be that some of these channels are actually on the eurobird satellite and not astra2.i have a skybox also and im not having any problems with these channels.

TWAG
Thats interesting twag.if the broken channels are all on eurobird then the dish needs a slight tweak to the left.because the other signals are strong,if your dish has moved a bit to the right you would still be able to receive the sky channels at 28.2.Maybe your dish is warped a bit Paul.
 

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I saw a post on one of the digital sat newsgroups recently and the lad had the same problem with NASN. It turned out there was a new cellphone mast in operation near his house, and the mast was leaking a signal into his satellite equipment. The down converted frequencies from the LNB were getting obliterated by the same freq out of the mast.

So - any new masts or cell phone repeaters been put up near you recently??
 

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Analoguesat said:
So - any new masts or cell phone repeaters been put up near you recently??
That's interesting. We live very close to a 28 floor tower block that has cellphone masts on it. I have no idea if a new one has been set up on there though.

It's very intermittent too. The other night if I switched to NASN I received a picture and sound for 5 seconds, then the picture froze and the 'no signal being received' message returned. Swap to another channel and back to NASN and the same thing happened.

Another thing is.. generally, I find that BBC2, 102, seems to be 'no signal' when NASN is ok.
 

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Apologies if this is long & / or badly formatted- its the info off the digital newsgroup. Thought it might be interesting for you:

>Some of you might remember me asking if anyone knew which Astra 28E
>transponder NASN was on. The answer turned out to be D9S. The frequency is
>11623MHz.

After being down-converted by the (Universal) LNB, then that would be sent to the receiver at 1873 MHz. You should keep in mind that the receiver does not receive the signal at the same frequency as is sent by the satellite.

>Today I investigated the complaint that started me on this trail. A >very nice US citizen living near here in a large apartment complex had >intermittent reception of NASN. No-one else in the block had a problem, but
>there again no-one else is American, and the other channels in the mux would
>only be of interest to lunatics. When I asked the analyser to analyse D9S it
>said that the channel power was just fine, but it refused to even consider
>decoding the datastream. I turned the line power off, thus disabling the
>polarity switch at the repeater. Exactly where D9S had been there was a large
>spike, only a few dB below the transponder power. The IF frequency is 1873MHz.
>I suspect a local cellphone mast.

That is highly likely, when 11623 subject to the 9750 L.O would be downlinked to the receiver at exactly 1873 Mhz.

However, there is one thing that you can do to get around this problem, provided that you have control over the 22 KHz tone signal in your receiver of course.

As the second L.O in the LNB is 10600 Mhz. This means that this 11623 MHz signal can also be downlinked at 1023 Mhz. And watching it at this frequency instead means no more interference.

Using a Digibox to do this is unlikely to be helpful, when this receiver only works one way.

This could also explain why other viewers do not report this problem, when receivers can switch between the lower and upper L.Os at different points. And 11,623 MHz is within the range when most receivers would consider switching over.

>In theory nothing should get into the TV system thanks to heavy screening,

Many earlier cable installations were far from ideal in terms of screening, where of course that was also before these signals were shared with the telecoms market.

I noticed interference myself on the same cable type as Sky's recommended CT100 cable. My solution was to upgrade the cable to CT125 spec (more correctly FT125), when then the interference on this frequency was greatly minimised.

Remember that the coaxial cable if the shielding is not good enough will act like a giant aerial. On large early installations, then the cable type could be far from ideal.

Anyone fitting coaxial cable these days of less than CT100 spec is really asking for trouble.

>but of course that's theory for you.

The professionals know far beyond simple theory.

>I walked
>right round the block with a screwdriver shoved into the analyser's input. The
>spike peaked at one corner. Above my head was a hideously rigged point-to-point
>microwave aerial -- one of those things that looks like a length of pipe. Dunno
>whether that was the culprit or just a red herring.

You would have to check the frequency output, but at that frequency it would have to be faulty.

Not to mention that by turning it off, then you can see if the problem goes away. Should it be the problem, then quite rightly the owner has to have it repaired, replaced or removed.

>Has anyone any experience of this sort of problem?

Anyone who values their satellite reception and have encountered what happens when the telecoms system shares this frequency range.

I noticed my interference problem during analogue reception, when under digital you would simply have blackness. Still my problem was not bad enough to take out digital reception, but I upgraded the cable anyway.

Before that time there was no interference...
 

rolfw

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Went to see a chap with a reception problem today, couldn’t receive Motors on Astra 28.2, no matter how I aligned the dish, there was signal there, but fluctuating quality.

Now Motors being at 11,303 Mhz, that would make the Intermediate Frequency 1,553 Mhz, switched off his DECT phone and Bingo , Motors back in glorious colour and stable as you like.

Didn’t think that these phones worked at that frequency, was obviously mistaken. :-)
 
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