Satking decoder strength and quality bars

[jclerke]

Hello all
I have been using a Satking VAST decoder for several years now when travelling around in our caravan. I usually align the dish manually at each location by going to signal finder menu and manipulating the dish till I get the strongest level on the TV onscreen quality bar. As soon as I have a reasonable signal on the quality bar the strength bar moves to a pretty high level of 80%-90%.
My question is does anyone know what the strength and quality bars actually represent? On my old analogue decoder one of the bars use to represent how good your connections were between LNB and decoder but this does not seem to be the case with the satking decoder.

Any help appreciated.
Thanks
John

[mtv]

John,

The signal/quality bars are indicative only.

There is no actual direct comparison to industry-standard signal measurements of DCP/BER/MER.

They are intended for the average user to obtain an approximate indication of reception, which you have been doing for some time now.

It's probable you could compare ten decoders of the same model and all ten may have a variation of 'displayed' signal indications.

The only real important thing with digital signals is that you have sufficient signal strength and quality to maintain reliable reception.

The most important factor is signal quality, as this determines if the decoder can correct any bit errors in the data stream fast enough to prevent break-up or loss of reception.

[jclerke]

Thanks for your response MTV. Seems as though the strength bar is a bit unnecessary on these decoders then.
John

[mtv]

Thanks for your response MTV. Seems as though the strength bar is a bit unnecessary on these decoders then.
John

A single signal bar 'may' be sufficient, but the two bars representing signal strength and quality behave differently.

In simple terms, Signal strength is a measure of how 'loud' a signal is and signal quality is a measure of how 'reliable' a signal is.

Both are important and interact with each other, but are independent of each other to a degree.

Eg: you can have high signal strength, but low signal quality, which usually results in unreliable reception.

If you have high signal quality but low signal strength, you 'may' have reliable reception, providing the signal strength does not drop below the minimum 'operating window'.

Another way of looking at it with satellite signals.... signal strength is more of an indication of how well you have the dish pointed at the satellite and signal quality will vary greatly with LNB skew. Eg: aligning the polarity of the LNB antenna with the polarity of the received signal.

For this reason, I go against what most decoder instructions say, of getting the best dish alignment first, because if you don't have the LNB set to an 'approximate' skew angle for your location, you may not get pictures, even with a strong signal.

So, set the LNB skew FIRST to an approximate position for your location, then align the azimuth & elevation of the dish.

Then make small adjustments to the LNB and dish to 'peak' signal quality and strength, giving priority to signal quality, as sometimes you may need to sacrifice a little signal strength to obtain the highest signal quality.

This has gone a little OT (how to set up a dish) but it may help you and others.

[jclerke]

OK Thanks for the elaboration.
John