if the locomotive manufacturers would remove the weight from the fuel tank on diesels and put the socket for the decoder there. No more disassembly to install a decoder. Just snap the tank off to install or replace the decoder. Same idea as repacing batteries in remotes.
An argument against doing that is that on narrow hood HO diesels (EMD GPs and SDs, Alco RS engines, end-cab switchers, etc.) the fuel tank is the only place the manufacturer can fit in a 1" speaker for a sound decoder. If you install a decoder there, you'd still have to open the engine up and figure out how to squeeze in say a 1/2" by 1" oval speaker (or 2 sugarcube speakers) and enclosure in the body.
Here I was ready to list my favorite Beach Boys hit...
Two of the locomotives in my roster, both electrics, had the easiest decoder plug-ins I've ever encountered. The Atlas AEM-7 has a small box on the roof that pops off and exposes an 8 pin socket that accepts a small motor-only decoder. Similarly, the Bachmann E-33 motor has a setup where the entire top of the long hood can be neatly lifted off to expose the PC board.
I'm with Stix, though. Speaker placement (or replacement) is important to me so chances are I'll be digging into the guts with the shell off anyway.
I recently installed Scale Sound System speakers in five Rapido Alco FAs. A chunky weight had to be removed from the rear portion of the loco to fit the larger SSS speaker. While handling the engine I noticed that the fuel tank was full of nothing but air. I stuffed this with weights that equalled the mass of the removed OEM weight.
Rapido_FA-fuel-tank by Edmund, on Flickr
Rapido-FA2_SSS-tank weights by Edmund, on Flickr
You'll also notice 1.25 oz. of stick-on weights in there, too. Nice to have the room in cab units for decent speakers AND sufficient weight.
Good Luck, Ed
I have a decade old Athearn GE demonstrator. The radiator grill pops off for a nin pin motor decoder. Easy Peasy Lemon Squeezee. It now has a Loksound decoder and ditch lights.
Pete.
A good idea in principle, but you need buy-in from decoder manufacturers. I have sound decoders in my Geeps that are too big for the fuel tanks.
It takes an iron man to play with a toy iron horse.