I think I have inadvertently sent you in the wrong direction - apologies. Looking at the attachment also emailed across, it's actually 79, not 53. I think it is hex, but if this helps the command for channel up is shown as hex 00, and this is the code that I am using and which works:

0000 006D 0022 0002 0157 00AB 0016 0015 0016 0015 0016 0040 0016 0015 0016 0015 0016 0015 0016 0015 0016 0015 0016 0040 0016 0040 0016 0015 0016 0040 0016 0040 0016 0040 0016 0040 0016 0040 0016 0015 0016 0015 0016 0015 0016 0015 0016 0015 0016 0015 0016 0015 0016 0015 0016 0040 0016 0040 0016 0040 0016 0040 0016 0040 0016 0040 0016 0040 0016 0040 0016 05F3 0157 0055 0016 0E5C

Perhaps you could have a bash? I really appreciate it!