The antenna on my 940 is not going up all the way. Shy or replacing it, are there any basic PM or corrective steps I can take to fix it? It does go up to the second joint without any issues and then it stops.

use WD40 or simliar to clean and lubricate, run the antenna up and down a couple of times - you will be suprised at the amount of crud. Assuming that the antenna isn't bent and that you can gently pull it to its furthest extension, it sounds like it just may not be extending enough on the motor. If that is the case then suggest remove it and refeed in. Whilst it is out you can clean the antenna as well from the inside to get all the crud out.