Don't get frustrated...
Same thing here...
xxx
I have flown airplanes with VHF COMM heads that could dial 117.xx -
And some others that could dial 136.xx as well, on the high end...
Yet the VHF COMM frequency spectrum goes from 118.0 to 135.999 mHz...
HF COMM heads that dial 2,000 to 29,999 kHz...
So, get confused with your XPDR...
Never say "it does not exist"... it very well might...!
xxx
Happy contrails