Hello,

I have three channels that are on the 20% threshold. Sometimes the channel starts at 20-21%, and I can see the channel; sometimes I start the channel at 18-19% and I have a black screen with no sound. However, if I start the channel and if the level is at 20-21%, if I don't change the channel, I can keep this level for hours. But if I start the channel and if it is at 18-19%, if I don't change the channel, it also stays at 18-19% for hours. Why doesn't the level vary?
Thanks,

If it's satellite, there are a few possible main reasons for behaviour like this:

- weather condition
- satellite drift in azimuth and elevation
- LNB temperature
...

Then, depending on even more aspects, like LOF precision, you will find some treshold style behaviour, caused by the AFC hold range being a bit wider than the lock range. More unpredictable symptoms may come from polarisation or position cross talk, irritating the PLL circuits.
Things get even worse on motorized dishes, due to arc precision and mechanical drive tolerances.

However, all this can normally be avoided by perfect dish and LNB alignment and / or a dish of sufficient size. If problems mostly occur at higher frequencies (of each band), the cable losses may also interfere.
Get away from the lower limits...

Thanks. I have a DVB-T reception.

So maybe you should think about a bigger antenna.
Just 2 or 3 dB more gain should help quite a lot.
An amplifier would not be that helpful, except if your tuner was half deaf.

Thanks, Jürgen, and happy new year's eve to you and Prog