I asked this question originally. As an update, I just finished installing a LocoFi-3 module, with a TCS KA-4 keep-alive, in a brass Lambert Models HOn3 Rio Grande Southern three truck Galloping Goose. It all just fit inside the shell, and it works fine with no signal problems even though the only opening into the brass shell is a roughly 5/8” x 1 1/4” hole in the bottom for the metal power truck, which then fills most of the opening.
Electrical pickup on these models is not very good and is difficult to improve, but adding the Loco-Fi plus a keep-alive appears so far to have led to very solid, reliable operation.
I asked this question originally. As an update, I just finished installing a LocoFi-3 module, with a TCS KA-4 keep-alive, in a brass Lambert Models HOn3 Rio Grande Southern three truck Galloping Goose. It all just fit inside the shell, and it works fine with no signal problems even though the only opening into the brass shell is a roughly 5/8” x 1 1/4” hole in the bottom for the metal power truck, which then fills most of the opening.
Electrical pickup on these models is not very good and is difficult to improve, but adding the Loco-Fi plus a keep-alive appears so far to have led to very solid, reliable operation.