One thing I have noticed whilst searching for RC Equipment is that there are a number of EBay Stores that either are based or ship from the Far East. This in itself is not an issue, but if it happens to be Synthesised equipment then a problem arises. The European 40 MHz channel allocation is different to the Far East 40MHz channel allocation. For example,
With JR Radio Equipment, Channel Number 71 Relates to a Transmit Frequency of 40.710 MHz whereas the UK Channels do not have a 71 equivalent, we in the UK use the frequency as the channel number ie 705 or 715. These relate to 40.705 MHz & 40.715 MHz.
As you can hopefully see, if you are using a Legal UK Equipment then you cannot transmit on 40.710 MHz as this frequency does not legally exist ! What can happen is that your 40.710 MHz Signal can interfere with BOTH 40.705MHs & 40.716 MHz systems.
Therefore, if you are using Far Eastern sourced equipment, then you run the risk of both causing and receiving interference and the subsequent possible loss of model.
If in doubt, there are plenty of shops that will give you guidance, or do a search on the internet. It costs nothing to ask, but can cost plenty if you get it wrong !!