How to use a sat 'finder'


It seems, due to the European Union, that some manufacturers would rather provide incomplete instructions in twenty languages instead of worthwhile instructions in any one language. Some try to get around the problem by using pictures with arrows - which can be confusing at best.

So here is a short article by Ewen Cathcart explaining how to get the best from your satellite finder...



Originally published in Frobnicate issue 22

In the previous issue of Frobnicate, Rick told us how to locate 28.2°E using a Digibox. This short article will provide a brief description on how to find any high-powered broadcast satellite using a dedicated satellite meter (also commonly known as a "sat-finder").
An example satellite finder. Would you believe this only cost a few pounds from Lidl? Some places charge upwards of 20 euros for one of these!For the purpose of this article I will assume that the satellite dish is fixed to a vertical pole, whether it be on the ground, or as part of a wall bracket. I will also be using a basic type of satellite meter that was recently on offer in Lidl UK. The meter has a 5 LED indicator and an audible tone (the more LEDs that light up and the louder the tone, the stronger the signal), plus a rotary knob for adjusting sensitivity.
This kind of meter is typically a lot less expensive than the traditional "needle" type. You can adapt the advice given here to fit your own circumstances.

First of all, you will need to decide how you are going to power the meter. Of course you can use a satellite receiver to do the job. However, any decent DC power supply capable of delivering 13-18v should be fine. I have a battery pack (10 x AA type) specifically designed for this purpose. I am not too sure how much current your average LNB draws, although in my case the battery pack did provide me with many hours worth of sat finding.
Anyway, if you are rigging up your own supply it goes without saying that you need to observe the correct polarity. Also remember that the 22 KHz tone is absent, therefore your LNB will only receive (and respond to) the lower band of frequencies.
If you desire both low and high bands (or high band only), then use a receiver with 22 KHz tone-switching. Most new digital and analogue receivers should have this facility.

Before starting anything the dish should be "roughly" pointing in the direction of your intended satellite. As Rick stated in his article, there is no point going for exact measurements, as you are highly unlikely to get it "spot on".
Nuts and bolts should be tightened to the point where the dish is secure but can still be moved by hand.

Make sure the sensitivity knob of the meter is turned so that it is in the least sensitive position. Next, connect up the LNB (using the fly-lead that should come with the unit) and the power supply or receiver. On my signal meter the first LED is always lit (this is normal, as it indicates that the meter is receiving power).
Now, adjust the sensitivity knob until the second LED comes on and a tone can be heard. Slowly, move the dish to the left or right until all 5 LEDs light up and the tone is at its loudest.
Now, turn the sensitivity down until the second LED comes on (as before) and repeat the procedure.
Eventually, you will come to a point where you will get no more improvement in signal. You can very very slowly move the dish to ensure that the signal is peaking correctly (you may wish to turn the sensitivity up again for this).
Once you are satisfied, tighten the bolts, although please make sure that the process of tightening does not cause the dish to move out of position.

Next, adjust the elevation of the dish. Again, the same procedure needs to be followed, until you can get no more improvement in signal. Now tighten all the bolts carefully.

At this point you might want to check the skew of the LNB. Slowly rotate the LNB left and then right in the holder until you find the best signal. You might need to do this if your dish is not sitting "plumb". Skew shouldn't be too much of a concern, especially if the satellite happens to be lying close to the centre of your particular view of the Clarke Belt.

The above procedure is very similar to the technique for finding a satellite using a needle signal meter. In this case, you start off with the needle in the centre of the scale and move the dish until the needle goes to maximum.
Needle meters tend to be more sensitive and therefore are more suited for homing in on the weaker satellites.

It might be a good idea to use this method of finding the satellite in conjunction with Rick's own Digibox method. That way, not only will you be sure that you are on the correct satellite (!), you will also be able to periodically check the signal strength (independent of the meter) and quality readings.
Certain digital satellite receivers (for example, the Comag ones) also have an audible beep that responds to quality level. The louder the beep, the higher the quality. I have tried both signal meter tone and satellite receiver beep together, and with a little bit of trial and error it is quite possible to home in on a satellite by audio means alone!


Ewen Cathcart, 2004


To Ewen's article I'll add some of my observations...


· Main index · Next:Thoughts on digital quality

Copyright © 2004 Richard Murray