...what is wet towel method?
The "wet tea towel" simulates rain fade of various margins by covering part of the dish with a suitably damp tea towel, allowing you to "fine tune" your installation.
1. Get a tea towel and one or two clothes pegs...
2. Soak the tea towel under a tap & ring it to help remove some of the water, but don't ring it too hard!
3. Introduce the wet tea towel down from the top of the dish face so that it progressively covers more of the dish until the signal you had prior to using the wet tea towel disappears - at this point, raise the tea towel back up the face of the dish slowly until you get the wanted signal back at a weak but usable level (i.e. it locks without picture break up), and once in position clip it to the top rim of the dish using the clothes pegs (or anything suitable to hold it in position - if only about half of the tea towel is covering the dish face, you might get away with it lying loose.
Notes: (a)If the wanted signal is really strong & the wet tea towel fully draped over the face of the dish face doesn't cause the signal to be lost, then soak the tea towel under the tap again and **don't** ring it out to force it to hold more water. If this still doesn't weaken the signal enough to cause loss, then either get a bigger tea towel(!) or work with what you have with the current tea towel covering part of the dish face (which should have introduced at least some signal loss otherwise either something is wrong or you're using a monster sized dish!), clipped on at the top of the dish rim. (b) if introducing any part of the wet tea towel on the dish face causes the signal to be lost, then your received signal was already very marginal to begin with - work on improving that first, then introduce the wet tea towel. If you can't improve your signal levels before even introducing the wet tea towel, then you probably already have about as good a signal as you can get with your setup otherwise.
4. With the wet tea towel in place, carefully but firmly tug the dish on its rim at its sides and top & bottom - if your signal meter readings show an increase in signal quality from tugging the dish in one particular direction, then adjust either the azimuth or elevation of the dish to ensure you have it pointing accurately at the wanted satellite, getting the best possible signal reading with the wet tea towel still in place.
Notes: (a) after doing the above, go back and repeat 3 & 4 again. (b) if tugging the dish sides shows a loss of signal quality in all directions (up, down, left, right) then you likely have the dish pointing at its best position. Go to 5.
5. With the tea towel remaining in place, now check the skew of the LNB, adjust for best signal quality results. Do this for several different transponders on the same satellite (if you can receive more than one) to get the best compromise.
6. Once you've adjusted the LNB skew for the best signal quality on both horizontal & vertical polarised signals, go back to 4 and tug the dish on its rims as a final signal check - if the signal quality level goes down in all directions then remove the wet tea towel from the face of the dish - your job is done! Otherwise, you'll need to fine tune the dish alignment again
In general, it is best to try this using the weaker received transponders from the one satellite position though in some cases it might be better to home in on a stronger signal first and then switch to a weaker one (what determines what is a stronger & weaker transponder will depend on location & the satellite in question, as an example in N. Ireland the signals from the Astra 2G European beam at 28E are a bit weaker than the UK spot beam signals from 2E/2F/2G at the same position). Transponders that broadcast using DVB-S2 8PSK as opposed to DVB-S tend to be a bit more "touchy" with incoming signals, especially concerning accurate skew adjustment and so such transponders are prime candidates for this method of accurately aligning the dish.
Also bear in mind that the wet tea towel will eventually dry itself out, and the tea towel might go from soaking to bone dry in a matter of minutes in dry & warm/hot weather, so you might need to re-soak the tea towel periodically.
