Thank you so much Ms/Mr Anonymous, I appreciate your time and knowledge.
I have on the laptop two plug holes similar to the one that you have provided a picture of. (However, it does not have the ear phone symbol beside it. ) The lead that I have to go from the computer to the transmitter has two jacks on it. The Black has no sleeve, and the red has a sleeve/collar. The sleeve/collar has an up down pattern to it.
I am thinking that maybe they do not both have to go into a computer or CD player or other machine that gives out sound. Maybe one [black] goes into a female hole, and the other red grips the hole [with the collar] that protrudes out of the machine? Do you think so?
Your views and knowledge will be appreciated
Ozzie in Bath UK