[Elecraft] K2 assembly question

[Soaring Eagles]

Actually 2 questions:

1. I made the first power up and everything went just like the manual. 
However, the preamp is marked on. The manual doesn't say which way it 
should be and I thought I'd check before I got too much farther.

2. I'm confused about soldering the RF probe. I can't seem to find a good 
way to position and solder the RG174 cable ends to the banana plugs. 
There's just a slight dimple at the end of the plugs and I can't figure a 
good mechanical way to connect them before soldering.

Thanks for any help!

K2 #5757 (in build process)
KX1 #1517 (4 bander)