In the past I used a remote for a AIWA Hi-Fi to control a AVR processor and circuit I custom made. I used an infrared receiver from Vishay (tuned on the 38 kHz) to demodulate the signal, then fed to the AVR (custom board, not Arduino).
The remote I have uses NEC protocol (http://www.vishay.com/docs/80071/dataform.pdf and https://techdocs.altium.com/display/FPGA/NEC+Infrared+Transmission+Protocol) that is based on pulse distance encoding.
The circuit controls fluorescent lighting (selection of lamp and intensity) in the living room and I found that it has some problems with interferences from the fluorescent tubes. The software already discards most of them but I'd like to improve it.
I would like to use the same remote (due to the multiple and nice looking buttons) but retrofit it with a 433 MHz transmitter.
Would one of the cheap 433 MHz emitters accept the signal meant for the IR LED, after a proper low-pass filter to remove the 38 kHz modulation? or would the 38 kHz modulated signal already work with the transmitter?
On the receiving side I have more freedom and I can put a demodulation circuit if needed, only the remote is space and electronics constrained, that is why I would like the simplest possible solution for the transmitter.
Clarified protocol and encoding