Stock TDC UI and TDC Mod

[EddieMuntz]

Hi guys,
I've had UBOAT since EA, and got back into it after watching Wolfpacks vids. Picked up the TDC mod which is great but I'm scratching my head with the stock TDC UI and what is entered into it that and the mod TDC, as I'm have literally hit and miss results.
So as an example of my process.
Target Speed - ID ship in stock recognition book- do the stopwatch thing - data imputed in to stock and mod tdc automatically.
AOB - from map work- Enter on the MOD tdc dial ( do i need to also add this to using the Stock UI Course/AOB dials?)
Range - Stadiometer - which enters date automatically into mod TDC and Stock.
Spread- Combination of using the vessel length dial and spread angle.
Matching torp speed etc between TDC and the Torpedo panel.
Entering run depth
Do i need to input the spread in this section also?
Then switch to green light on the torp panel to use the TDC mod data.
Then fire,

Its just a made a save at the point at which all this data is inputted, and i cant get a consistent hit and just wondered if inputting into both is messing up the solution, or does the green light switch on the torp panel negate any data in the stock tdc?

Thanks for you time.

EM