I have purchased an Atlas HO Master GP-40 - Analog engine and want to install a sound decoder.  My problem is I cannot fine the exact light board anywhere on the Atlas site.  It has a 21 pin as well as an 8 pin socket.  If I go with the 21 pin how is the speaker installed?  The existing board space is too short for any board replacement.  I do believe there is a socket on the existing board that may be a socket for a speaker plug.  Since I cannot find a detailed drawing of this light board where do I go to find one.

I want to feed 12 VDC into my Roundhouse. It has 27 GOW incandescent bulbs that draw 1.45 Amp. Wired in paralell. I would also like to reduce the voltage to about 10.5 V to prolong the bulbs. So, if anyone can help me: What type and value of Resistor would do this? What size dedicated transformer and rectifier would I need to supply the power? Yes, I could have used LEDs but I like the glow from these for structures and street lights. Thank you. By

I'd like to explore options for onboard (inside the locomotive) DCC controlled actuators.  There are a number of commercial solutions for accessory actuators that are stationary - such as controlling turnouts. However, there doesn't seem to be many options for onboard that are small enough to fit inside an HO switcher.

Finding small actuators doesn't seem too difficult. I've found and acquired the following:

Hi all,

Just jumped into the deep end of the pull from N scale to HO. 

In my last N scale adventure I quickly found that sound units needed juiced frogs for any kind of reliable operations. 

Is this the same for HO?  I am getting ready to lay down track (Atlas C83) #4 custom line switchs 

{ please before we get off onto the wrong spur, there is a ryme and reason for my track choice. I am not switching at this time. }

This for all intents and purpuses will be a temporary layout.