Another thing. The whistle and bell functions in the tender operate independently of the engine even in command so there will not be any need for any other electronics to operate the sounds.
I checked it out by putting the tender on the track in command mode and could operate both the whistle and bell with my CAB1 remote.
Uhh... Not with the command version of RailSounds installed. The commands for it come from the R2LC (or R4LC) and not from the track. Since there is no TMCC receiver in the audio or power board for the RailSounds package, it's not possible to receive the TMCC whistle/bell commands with the tender along for a command model.
The only way that the tender on the tracks along can respond is if it thinks it's in conventional mode and it's seeing the DC offsets on the track for either the whistle or bell. If it's not connected to a locomotive, it would indeed believe it was in conventional mode. That's the only way the whistle or bell is being activated.
I don't know what you're testing, but I've put together a lot of upgrade packages, and I can assure you that the TMCC command will not be received by the tender directly. That also applies to OEM products from Lionel that have RailSounds in the tender.
