Interference

Looking at an OS map a couple of mobile phone masts have been identified which, if you draw a line through them, exactly cross our flying field in the corner where so many of us have experienced glitches. Bear in mind that, if this is the case, then the interference will be found all along the course of this line so it will also extend into the field to the East. Checking on Ofcoms web site these are both mobile phone masts .  It is not the easiest of web sites to navigate but you can get to both locations and it confirms these masts are used for mobile phones.   It is possible that there is a microwave beam between these towers and that we fly through this causing internal interference in 35MHz receivers (2.4GHz receives are largely immune to this interference).  We will be contacting  the BMFA and asking their advice and assistance in checking and confirming if this is the case, but whether they can do anything about it is another matter.

Until we get some feedback the following advice is given in the BMFA 2010 Handbook which members, especially those flying on 35MHz, may find useful.

Page 31,clause b) Radio Control and your Club

The UK is crossed by many low level microwave communication beams and the number of these has increased dramatically since most cellphone masts have been converted from landline feeds to microwave interconnection.  If one crosses your field it may cause problems with interference and glitching, particularly with 35 MHz radios.  If your club member’s suffer from such interference regularly (usually in the same place on the field) then it may be a microwave problem.  You can guard against it completely by simply wrapping 35 MHz receivers in a layer of aluminium cooking foil, making sure to tightly crimp the foil for about 5cm out along both the receiver aerial and the bundle of servo leads. The interference affects the components of the receiver directly and doesn’t work through the aerial.  Note that some receivers already have a conductive coating of carbon sprayed on the inside of their plastic case which has the same effect as the external foil wrap.

If you believe you have experienced interference then please complete the BMFA form and send it to one of the committee who will arrange for it to be forwarded to the BMFA.  Click here to download the form in Micosoft Word format or here to download a PDF copy

Last modified: November 01, 2010