For HO scale, yes. Use his phototransistors. I have his crossing gate flasher/gate kits and the phototransistors he provides for that fits between the ties.
Elmer.
The above is my opinion, from an active and experienced Model Railroader in N scale and HO since 1961.
(Modeling Freelance, Eastern US, HO scale, in 1962, with NCE DCC for locomotive control and a stand alone LocoNet for block detection and signals.) http://waynes-trains.com/ at home, and N scale at the Club.
Is there a phototransistor made that would fit between the ties without cutting them of a Peco C100 track? These would be used on Rob Paisleys` 4 circuit photodetector boards.
Bob D As long as you surface as many times as you dive you`ll be alive to read these posts.