The technician's response was to that post was:
The customer describes what I believe is a mechanical issue with a cable connection. I recently had a very troubled customer with an identical problem and after five visits to his home, I discovered the cause of the problem to be a power-passing splitter in line with the preamplifier. During the day, the antenna system worked fine and on clear nights or on various cluody days, suddenly fail without warning. The splitter was good but the center connectors were sprung too wide.
Some newer splitters, lightning arrestors and cable splices are constructed of a multi-leaf center conductor contact that can be sprung too wide for reliable contact of smaller center conductors. For most RG-6 cable of #18 center conductors, this is not a problem but for some non-name RG-6 cable and especially RG-59 cable using #20 center conductors and smaller, this can lead to a very elusive intermittent contact, later in time. In other cases, the center conductor contact of the "F" jack is rather far into the connector body and a short center conductor length may also make intermittent contact.
Ask the customer to check each cable connection for at least 1/8" center conductor length beyond the top of the connector body. More importantly, make sure there is some resistance as the cable connector is inserted into the "F" jack. This will confirm that the center conductor is making reliable contact. Look at the interior of each "F" jack and make sure the center conductor contacts are closed. Check everything, including wall plates, cable splices and lighting ground blocks.
During a period when there was a loss of signal, I tried temporarily bypassing the ground block and wall jack by hooking the antenna coax directly to the digital converter box but it didn't improve anything. So now I'm at a loss as to what to try next?
To save some money I used preformed coax (GE brand, 18awg) and wrapped the exterior connections with coax seal. All connections were snugged tight with a wrench. There's about 74' from antenna to TV. We have a Digital Stream DTX converter box and HD7696P antenna. No signal splitters. A HDP269 preamp didn't help so was returned.
There's a pine tree about 25' in front of the antenna. When I moved the antenna across the roof to clear the tree from line of sight only one channel grew stronger while others weakened slightly. Normally most of our channels are in the "green zone" on the converter box - 71 to 90 on the meter, but some days we lose channels for hours or the whole day. Weather doesn't seem to factor in.