Great Circle Map of the World centred on the Kingdom
of Fife, Scotland. This shows you the shortest possible path from
Scotland to any other place in the world. As used by radio waves and
aeroplanes !
What parts of the world can you hear right now in Dunfermline ?
Click here to find out !!
3860 kHz Interference If you hear a rough-sounding and very broad signal centered at 3860 kHz there is a high probability that the source is a T1 data line within a half-mile or so. Internet data service provided by DSL, wireless, and various other means sometimes is referred to as T1 where the bandwidth approximates T1 bandwidth. However, they are not true T1 circuits and do not cause 3860 kHz interference. True T1 lines carry what is called a DS-1 signal. The data rate is 1544 kHz +/- 75 Hz. However, the transmission mode is bipolar using a code called Alternate Mark Inversion (AMI) which causes the pulse repetition rate to be 2.5 times the data rate. (2.5 x 1544 kHz = 3860 kHz) Signals at that frequency are sent in both directions down two 100-ohm twisted-pair balanced transmission lines that are often not shielded. Changing to shielded lines significantly reduces interference radiation.
