[Stu038]

Sorry I've not rejoined this discussion sooner but unlike Ignition I got a life beyond the forum

Much as it hurts I got to agree with him here though, I just don't see how more people using the RF can make the carriers reduce in power.

As we seem to be into dodgy comparisons

If 200 people are listening to Radio 1 everything is ok if 250 are listening then the signals poor? Sorry but RF doesn't work that way.

Both the signal and the carrier can be affected by many things, distance from source, transmission medium, interference in many shapes & forms but not by capacity of usage.

While Monkey maybe partially right with the temperature bit, Ignition may be as well. The problems there are generally related to the fact that the thermal AGCs are normally designed for the American market where everything hangs on poles. What they do is sense the increase or decrease in the temperature of the amplifier and then increase or decrease the RF level accordingly working on the basis that the attenuation of the cable is also increasing or decreasing. The problem though is that in the UK the majority of the cabling is in underground ducting so therefore is not affected by the weather.

Hence you end up over or under driving your amplifiers which not only creates level fluctuations but also horrendous distortions.

The majority of the franchises I've dealt with worked that one out in the early 90s.

Please reassure me that the Telewest network is not overhead or that its not still using thermal AGCs incorrectly.

Originally Posted by Ignition

Modems tend to be rather attached to upstreams and can take hours to give up on one if they do at all. Depending on segmentation they may not even have another upstream to choose from.

Frequency hopping mate, we had lots of problems with it in the early days, that's why the flaplists were a god send.