1 dbw is equivalent to how many signal percentage?

It isnt really - the % on the receiver meters is an indication nothing more.

Use 2 receivers on any one system and you will get different results depending on how sensitive the tuner is, its performance with that particular lnb etc.

Ignore the signal strength it shows little more than the lnb is connected. Its the quality you are interested in - the higher the better.
 
1 dBW equal 1.25 watts, this signal level will blow the receiver right off the table top.
 
Where are you getting the dBW readings from????

dBW is one watt of RF power equal 0 dBW, it should not be used in this case, dBM, dBmV or dBuV would be more inline.

Code: 
http://www.rapidtables.com/electric/dBW.htm
 
A fully saturated LNB (maximum signal for 1 dB of compression) will at most put out 0 dBM at the "F" connector, this is equal to 1 milliwatt into 75 ohms.

All this can vary between different brands/types of LNB's.

0 dBM equal -30 dBW.
 
I think italy2006 means dBm rather than dBW, although I could be wrong. Anyone who has been archived for 10 years could make such a mistake.
 
Analoguesat said:
It isnt really - the % on the receiver meters is an indication nothing more.

Use 2 receivers on any one system and you will get different results depending on how sensitive the tuner is, its performance with that particular lnb etc.

Ignore the signal strength it shows little more than the lnb is connected. Its the quality you are interested in - the higher the better.
Click to expand...

Indeed, I've had a fiasco recently after buying another receiver and seeing a 15% increase on some channels whilst others were about 30% lower, and some others not even getting picked up at all! Surprisingly, the cheap Openbox I have remains the best tuner I have in my possession - picks up feeds on my 80cm that I've been told would only be seen by a 100cm+
 
The only real way to tell is with an RF signal generator setup for a 75 ohm impedance modulated with the correct signal for a standard satellite transponder.

This way you can extract the true scaling or the receivers meter functions, as they are mostly based on DC voltages (RSSI) from the sat tuner into an A to D converter chip, the software in the sat receiver then converts it to a display.

And I use an old CoolSat 5000, it has the best tuner in it I have ever used, I set it up in the lab one day and checked it's "S" meter, for a 99% reading it was looking at a Beldin RG-6 quad coax length of 1 foot with a zero dBm output on the RF generator, on a 200 foot length of the same coax it dropped to 50%, this was equivalent to a 41.2 dB drop in signal at 1 GHz.

So I could scale it up from there.
 
italy2006 said:
LOOK AT THIS LINK
FlySat Eutelsat 16A @ 16° East Beams
for every dish size, there is a dbw.
so my question is how we can describe relation between dish size and dbw in term of signal quality.
Click to expand...
You can´t!
The footprint maps are a theoretical estimation of the power received from the satellite at the designated point of focus, don´t think anyone goes out with a meter to check but I could be wrong. As you can see the strongest signal is at the centre of the intended reception area, from which you can make an estimated calculation of the required dish size for stable reception in that area. Hence, as you move from the centre the size of dish increases for stable reception. I guess there is a calculation somewhere which could give an approximate signal quality against dBW, but at the end of the day it does not really matter.
The signal strength and quality in position " alpha " will be governed by the size of dish. If you were on a calculated dish size area of 80 cm, then fitting a 100 cm dish would give you more signal strength and usually better quality. However, if you were in position " Beta " which requires a 10 cm dish, on a 60 cm , 70 cm , etc should return 100 % quality on all of them, unless of course the strength exceeds the max input level of the box, thus flooding the receiver and causing loss of reception without the use of an attenuator.
Fact is, right size dish and decent strength should give decent quality, normally measured in % or dBm. ( dBW is irrelevant when relating to box signal indicators )
 
For dBW to make any sense you need to know the input power.
 
italy2006 said:
LOOK AT THIS LINK
FlySat Eutelsat 16A @ 16° East Beams
for every dish size, there is a dbw.
so my question is how we can describe relation between dish size and dbw in term of signal quality.
Click to expand...

OK now we have something to reference to, the dBW readings shown in the foot print maps are the calculated transmitter IERP power levels at the satellites antenna(s) for that transponder.(transponders RF output power plus antennas gain)

So a couture showing 50 dBw would be equal to +80 dBm, deduct the free space path loss of about 150 dB,(22500 miles at 12 GHz) would give you a signal at the ground of -70 dBm or 10 micro volts, add your antenna gain to that level, lest say 35 dB, so take that away for a signal level of -40 dBm for an RF voltage of 3.16 mV.

For ever 3 inches of increased or decreased antenna diameter you can add or subtract about 3 dB. (-37 dB an increase in power, or -43 dBm a decrease in power)
 
What happens in the case of a 2" diameter dish ?
 
You get two thirds of eff all.
 
Or, the square root of a Cocoa Tin
 
when I wanted to catch one of asiasat tp, my friend told me if dbw level of dvb card reached 9 you can get channels.unfortunately my dish wasnot so big and dbw level just reach 8.5.
so i think you my freinds have made matter very complex so i couldnt understand most of them.
if anyone familiar with dvb card , please explain what does mean dbw in dvb card and its relATION TO signal quality or percentage.
 
Better asking question how to get more from your setup tweaking new lnb etc could give you the little bit more needed for lock
 
I have never had or used a DVB card, only ever had STB´s ( Satellite receiver boxes , also called set top boxes , which also includes terrestrial decoder boxes ) so I don´t know why your card reads dBW , as usually boxes report dBm or dBuV.
However , if the signal you are trying to receive is an HD with high frequency error correction ( FEC ) it will require more signal to work than a SD signal , or one with a lower FEC.
I hope that one of my esteemed forum colleagues who is familiar with such cards will reply in " laymen s terms "
 
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