Grumpy_Mike:
Wavelength is the wrong thing here. Period is how long it takes for one cycle
Thanks for the explanation - I had a feeling that wavelength was the incorrect term.
Chagrin:
You should be using a TSSP4038 or TSSP58038. With those receivers you don't need a gap time thus it's pretty straightforward to build an IR emitter with just a single 555 timer.
Thanks for the tip! That's perfect - I will use one of those receivers instead.