That lower part should be taller, and more detailed.
The edges/whatever they are of the main, tall section look better white/what colour you used for the other "white" parts.
If you want it hollow and looking better, it's better not to make those windows transparent.
The fact that (it seems like) you used lengths different than the default brick lengths is really good.
You should give us screenshots of the antenna, from what I can make out I suggest giving it more detail.
I give it a 6/10.
Poll