[Kymmy]

Two things will effect the signal, transponder ERP and also the position of the sat. Think of Astra2 as three sats all moving inside of a box in space, if your dish is perfectly pointing towards the middle of the box you'll get a good signal from the inner sats and an OK signal from the sats near the edges of the box. If your dish is slightly out then the other sats will be even weaker.. Mix that with varying transponder ERP's and you then have an issue.

If you need to keep the join then you need to check that the cable is good and that the connectors are joined to the cable properly and securely.. A good connector might equate to adding 1m to a cable (same attenuation) where as a bad connector might be the same as adding 20m to the cable) Even then it might not be enough