ChristianH, on 07 October 2012 - 12:39 AM, said:
I hope all this makes sense.
When your masthead is turned down with the gain switch on low, it is not supplying any gain, only a small amount of noise, which shouldn't be affecting the signal too much.
Therefore, you could try bypassing the amplifier with a F connector barrel, and see what the result is then.
Presumably you have updated the coaxial cable at the same time, if you had the mast down to change the antenna over.
While the mySwitch site may show good signal strength for your location, this is a guide only.
It doesn't give any indication of the expected signal quality.
If there are areas of variable coverage around your location, I would be inclined to consider that your antenna positioning is going to be critical.
The Panasonic showing strength 10, quality 0 suggests to me (obviously, perhaps), there is a signal quality issue. You could try retuning the TV, if not already tried, although I can't see how this would change things.
If you are going to lower the mast, I'd be trying the antenna lower down, and adjusting orientation, just to see if it causes an improvement.
Bear in mind, my previous comment about antenna type & position being critical to good reception*.
*Last week I dropped a 6.5M mast installed on the second level of a house, (in the analogue days, for reception in a bad area), about the same distance from the transmitter as you. After an hour or so of testing, the best spot found was 1 meter above the same roof, about 3 meters diagonally lower down from the ridge where the foot of the mast was secured. This was in an area of terrain & vegetation blocked reception.