5G Card or even Possible 4G to us eon old vintage car phones 2G

Do you have anything that I could change the guts out of the brains in the transceiver (not sure if that’s the correct terminology) box and replace with a 4g/5G card to make one of these work on today’s network (https://www.ebay.com/itm/284826500225?h … Sw0aVii98d)? I have seen this guy’s post (https://www.electro-tech-online.com/thr … 0s.162764/) where he is using a modern phone and going through the Bluetooth, but I would rather stay as original as possible if it can be done. I really appreciate any help you can provide.

Jim

It is certainly possible, if you are reasonably good at electronics. One could fairly easily reuse the case, keypad, microphone and speaker, but probably not the display (have to take the phone apart to be sure).

This article is fun: https://www.sparkfun.com/tutorials/51