Q: Can I use non-Digitrax decoders on a Transponding layout?
A: Yes.
If you want to add transponding to a decoder that does not have the feature, add TL1 or TF4 to the decoder.
Some non-Digitrax decoders that use supersonic features are not compatible with transponding unless you switch off the supersonic feature.
Digitrax supersonic decoders are compatible with transponding and can be used in supersonic mode while transponding.