Greetings one and all. I'm new here and asking for help.
I've been asked to assist a friend who is setting up a 00 track, but has no experience with 'DCC rail networks'.
He has a Bachmann "Class 20 Diesel 20023 RailFreight with indicators discs" Model #32-029, and bought a second hand DigiTrax "Challenger" kit comprising of a DB100a Booster, CT4 Quad Throttle, but sadly it is missing the DH84 "Digital Command Control Decoder".

The "loco" has no documentation to support the "DCC READY" claim, and the "decoder" was retired 30 years ago.
DigiTrax do still support the Bachmann rail stock https://www.digitrax.com/products/engine-matrix/decoder/ but where would I establish if the current decoders models work with the DB100a and the loco.

So before I start from first principles with my bench supply and oscilloscope probes, I am hoping that someone here could ease our introduction to getting this combination working.
Any help would be greatly appreciated.

Thanks in anticipation,
Best regards,
Alan M.