All posts by Chris.SE
Below are all of Chris.SE's postings, with the most recent are at the bottom of the page.
Darren Brown:
Hmm, those figures didn't quite behave as I was anticipating.
Interesting what you've said about having the two filters.
It's going to be a case of a bit of experimenting, Leave both filters in place.
Try first turning the gain down a bit at a time and watch the figures.
The try turning the gain up a bit at a time and watch the figures.
Make a note of the figures as you go, as well as the position of the gain control.
What you are looking for is 100% Quality with as high a signal strength as possible, but what you have to watch is if there's too much gain the strength "figures" start to creep down again and it can then have a detrimental effect on the Quality.
I can only guess we may have a combination of factors here, changes in propagation conditions as dusk approaches and some interference compounding matters.
If you can't find an optimum, then maybe a change to Pontop Pike maybe the next best thing to try. Can you safely access your aerial yourself?
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Darren Brown:
HI Darren, well that's certainly looking somewhat better.
Here's another experiment you can try -
Leave the gain where you have it and put both filters in series on the input to the booster and see how that affects the figures.
Post the results of that, it will be interesting whatever they do.
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Darren Brown:
I also have the search box issue, so it's the site!
The last set of figures you posted are excellent. I think that proves beyond doubt that mobile cell interference is a primary problem here.
Chatton is currently on Planned Engineering, so there can be other variations in signal, so some of the "drop-outs" may be just that. U&Dave is on COM5/ArtqA.
It's encouraging signal returned at about 9.30. I think as you have now got some good figures, it's a case of watching what happens for a while.
Post the figures when you get any noticeable changes that persist for longer periods.
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Harro:
This is most likely to be recent local weather conditions causing changes inn signal propagation, this can sometimes occur with high pressure.
Do NOT retune though. You cannot tune to signals that aren't there or can't be decoded, the usual result is to clear the correct tuning.
If you are now missing a multiplex ie. COM4/SDN then MANUAL tune UHF channel C32 until you restore it, then don't retune, you just have to wait for conditions to change.
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Wednesday 9 April 2025 12:10AM
Darren Brown:
This is looking a bit like too much signal. In that situation, the front end of the receiver is overloaded and signal strength readings go down because of the way AGC circuits work and so does the signal quality.
Turn the gain down a bit more and post the new figures.
The primary reason the filter needs to be on the aerial side of the booster is so you don't amplify the interfering mobile signal which could also saturate the booster as well as the TV receiver because the filter on the "wrong" side may not reduce it enough either.