A 1.8m won't be as reliable as a larger dish and may have periods where it 'works' and other times where it won't. More susceptible to adjacent interference. And getting everything 'just right' requires a lot of patience.
Feed centered and square to the dish. Focal distance optimized, etc.
Maybe spend some time on 99 getting the Q absolutely maximized. Then, if there's improvement, try 101 again(?)
You can check if the winds have warped the dish with a couple of strings. One across the face vertical, and another at 90° to it. The strings should just touch where they cross. Then place the vertical string at a 45 across the face, and another 90 to it. Again, strings should just touch where they cross.
For a larger dish, Keep an eye on the thread more Craigslist dishes for your perusal One may be within reach.
Good luck and happy hunting.
One night I walked home very late and fell asleep in somebody's satellite dish.My dreams were showing up on TV's all over the world. -- Steven Wright
Openbox S9, Pansat 3500SD, 139w to 55.5W +30W
10Ft USS Steel BUD and an assortment of ChannelMaster dishes, (1)84e, (2).7m, (2)1.2m,(1)1.0M, (1)2.4m[8ft] offset in storage.