Author Topic: Freesat  (Read 3095 times)

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Offline Ian

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Freesat
« on: November 02, 2010, 07:50:48 am »
Snippets about tuning, changes and how to sort out problems.

The best source of info about Freesat and Freeview is Satcure.  Many of the tips and hints are drawn from their excellent newsletter.
« Last Edit: November 02, 2010, 07:58:18 am by Ian »
Nothing is so firmly believed as that which we least know.  ― Michel de Montaigne

Si hoc legere scis, nimis eruditionis habes.

Offline Ian

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Re: Freesat
« Reply #1 on: November 02, 2010, 07:51:57 am »
BBC satellite channels changed frequency on Monday 18th Oct. See

BBC freesat

If you experience a problem, reboot your receiver first of all before messing with any settings.
Nothing is so firmly believed as that which we least know.  ― Michel de Montaigne

Si hoc legere scis, nimis eruditionis habes.


Offline Ian

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Re: Freesat
« Reply #2 on: November 02, 2010, 07:55:08 am »
From Satcure's excellent newsletter:

There are many sellers on eBay who have very little knowledge of the products they are selling. The result is misleading claims that might fool you into buying something for the wrong reason. As an example, take LNB amplifiers. In almost all instances, a slightly larger dish will outperform a small dish with a booster. But that fact doesn't deter people from buying boosters!

See http://search.ebay.co.uk/sky-amplifier

Anonymous seller "d4nn7" offers:-

"New improved design to give a variable signal boost avoiding over amplifying stronger signals while giving extra amplification to lower signal channels. Will not give picture problems by over amplifying signals. Better performance on lower gain signals."


I can assure you that these claims are complete rubbish. It's a standard LNB signal amplifier with gain slope equalisation to compensate for long cable runs. If you feed it with a strong signal, it WILL over-amplify the signal. It has no built-in intelligence to prevent it from doing so.
Nothing is so firmly believed as that which we least know.  ― Michel de Montaigne

Si hoc legere scis, nimis eruditionis habes.

Offline Ian

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Re: Freesat
« Reply #3 on: November 02, 2010, 07:56:37 am »
More...

A company calling itself "Digitalis" gives a more honest (if misleading) explanation of the "equalised slope" amplifier. This is designed specifically to compensate for a long cable run. It has no other purpose than to overcome losses in a long cable.

A company calling itself GMAX is selling a very cheap LNB amplifier that does NOT have slope equalisation. It states "This excellent device is perfect for boosting a signal on a long run of cable." In fact the reverse is true because it has no gain equalisation. This amplifier is intended for boosting the signal to compensate for losses in an LNB switch or a signal splitter. It has no other purpose.

Let me explain briefly: Coaxial cable loses signal along its length and adds "noise". The signal losses are higher at higher frequencies. An amplifier with "equalised slope gain" gives an additional boost to higher frequencies so that all frequencies coming out of the far end of the cable are roughly equal in amplitude and at a high level compared with the "noise" added by the cable. It uses the same principle as a hearing aid for older people.

So you might need an "equalised slope" amplifier to compensate for a long cable run.

An amplifier without this feature will result in low frequencies being boosted more than high, resulting in unequal amplitude signals, which is bad news.

A drawback of all amplifiers is that they also add "noise" and they can only amplify what they receive. If the dish is too small and provides a weak, noisy signal, that's what gets amplified. (If you make enough weak tea to fill a bucket, you'll still have weak tea.)

Nothing is so firmly believed as that which we least know.  ― Michel de Montaigne

Si hoc legere scis, nimis eruditionis habes.