On Wed, 19 Nov 2014 12:57:30 +0000 (GMT), Jim web wrote: > Be interested to hear if anyone else has had the same sort of weird > behavior that seems to be phased with sunset!
ADSL is affected by interference from MF broadcast stations. During the day the ionosphere is "wrong" for the long distance recepetion of MF stations and you can only hear local stations via the ground wave. At night the ionopshere changes and reflects the signals from MF stations over the horizon and you can receive them via the sky wave. Under the right conditions it's possible to hear east coast US MF stations in the UK. Normally all you can hear are stations from all over Europe. This added "noise" at night can play merry hell with ADSL2 which uses frequencies from 125 kHz to 1.1MHz (or 2.2MHz for ADSL2+) for the downlink. The MF broadcast band covers 530 kHz to 1.6 Mhz. I know if my ADSL resyncs during the day it'll do so at aroound 7 Mbps, come evening the noise will have increased and the error rate skyrockets, thus reducing throughput and causing the connection to drop, though unless it gets really bad it won't actually resync. Resync at night and it'll be just over 6 Mbps, this produces a stable connection day or night that is relatively error free. What is a bit odd about your "fault" is the fairly regular timing. Sync during the day could well be way above what it can do at night hence the drop at sunset (though that seems a bit early). In the morning the reduced noise prompts the modem into resyncing at a high rate, ready for the evening... Apart from the last 50 m or so our line is undergroud. I can imagine that a line with a lot of overhead would be far more sensitive to this diurnal change in noise level. -- Cheers Dave. _______________________________________________ get_iplayer mailing list get_iplayer@lists.infradead.org http://lists.infradead.org/mailman/listinfo/get_iplayer
