Cannot acquire satellites 99 and 103

The problem is your dish is not aligned. A properly a;igned dish will have signals mainly in the high 90s or even 100 on satellite 101, Until you get to that sort of signal levels you probably won't see 99 and 103 at all.

I am getting the mid 80s on 101. The 103 and 99, while I can find them, just don’t get a high enough signal strength. It doesn’t matter how much dithering I do I cannot get 103or99 signal strength to an acceptable level. 

Tomorrow, 

tomorrow I will give it another try. 

you are not supposed to dither on 99/103.  dither on 101 until you get very high 90s or 100 on the 101 transponders. then look at 99/103. a very small movement on the adjustment screws should get you the 99/103 signals you need.

It looks like you don't really undestand how dithering works.  The objective is to find the center of the 101 beam which is pretty wide. Forget 99/103 for now. 

Pick a 101 transponder with a high signal strength. move the dish with the fine tune azimuth adjustment until the signal drops to say 65. Record the setting of the fine tune dial. Then use the fine tune to move the dish back through the high signal point until it drops again to 65. Record exactly how much you had to change the fine tune dial to get to that point. Then divide that azimuth change by 2. Move the dish back exactly that amount. You will now be at the center of the beam in azimuth. If most of your 101 signals are not close to 100 repeat the whole process but with the elevation fine tune. You should now be at the center of the 101 beam in both azimuth and elevation. Your 101 signals should now be mostly at or near 100.  If they are not, you have another problem like the mounting post is not vertical

Assuming your 101 signals are now OK, look at 99/103. If you are lucky and have done a good job with dithering most of your 99/101 signals should at least be in the very high 80s. If not, make VERY small adjustments to the azimuth/elevation fine tune until 99/103 are in the high 80s mid 90s. Don't worry about 99s/103s because they carry spotbeams and so many of them will be low or zero.

Exactly @TexasBrit , and for you @rbdaves recheck the elevation and tilt to be sure it is exact. If it is a little off, the desired signal will not be achieved. Also be sure that the mast is level in all directions. (check to be sure that the mast is mounted correctly and that it stays level when the dish is put on)

@detuch254 & @texasbrit:  

Thanks for your input.  Up until the pandamic grounded me, I had set up my dish scores of times.  On this trip, I have had to review the setup process.  Previously, I aimed the dish by swinging it back and forth until I got a “hit” on the Genie box signal strength meter.  I think that is “dithering” (new term for me).  then I fine tuned elevation with the elevation adjustment on lower left of mount.  To fine tune the Az, I just made very minor adjustments by tapping dish one way or another.  I avoided manipulating the lower right bolt because it looks like there are pop rivets that seem to disallow any movement. Am I missing something? Do those rivits actually allow slight adjustments without breaking anything?

Yes, there are two dithering adjustments on a regular DIRECTV Slimline dish. You can use both to adjust the dish and nothing will break. One of the dials is for azimuth and the other is for elevation. This is the main reason why your signal is so low. Tapping the dish one way and another won't do ANYTHING. The lower left and right bolt can be moved with the wrench until the signal strength is your desired strength.

There are videos on youtube that might help.

Yes, if you are looking for YouTube videos to help you with dithering and elevation and azimuth. Follow along with this video from @litzdog911 : https://www.youtube.com/watch?v=QA1krU8eo8E&t=763s

I posted something here and it disappeared, so here goes again:

I watched the video…familiar info - I’ve set my dish up scores of times as I have travelled around in my RV for about 18-years.  I had an extra mount and LNB and swapped them both out, but still could not get a good signal on 99 & 103.  I found this setup at a yard sale and it probably has something wrong with it.  Even though I can’t acquire 99 and 103, I can watch TV, so I’ll be looking around for an eventual replacement.  Thank you for your help.

@rbdaves if you tried all the dithering and still can't get a signal on the Hi-Def satellites, you can try to make sure that there are no obstructions blocking the satellites, be sure that the elevation and tilt are EXACTLY correct as stated on dishpointer.com for your location. After checking and making sure you satisfy these points, it comes down to the fact that the yard sale dish is BENT slightly. A defective LNB is probably not possible because the OP stated they swapped LNBs and still had the same issue. @TexasBrit how do you feel?

rbdaves - so now what signals do you get on 101??

I have set this dish up five times on this trip from CA into OR. There weren’t any obstructions on the last four setups. The results were always the same: Good signal on 101 but not 99 or 103.

I checked dishpointer.com and the magnetic azimuth and elevation were the same as the numbers provided by my DirecTV Genie box.  Dishpointer.com doesn’t provide tilt, at least I couldn’t find it.  The genie box provided a tilt number of 111.  The tilt numbers provided by the Genie during this trip into Oregon have been in that range.