Speeding Ticket
I tried the speedo off thing because of oversized tires once. The judge said if I wanted to use that as a defense then he would have a ticket issued for defective equipment. The courts are so busy with real crimes like felonies they do not have much patience for this petty ticket stuff.
Also the judge can remove you from represent yourself just like they can do with an attorney and then you will have to pay an attorney which will be way more money than the fine. If you are eligible you could get a public defender.
If you know you were speeding then be a man and accept you punishment. These whole loophole things just to keep from paying for something that someone did is crap. If you really know that you were not speeding then yes you have a case but it will cost you more than it is worth and because of the technicality stuff that happens every day in courts just like the what you are talking about doing they will not believe that you were not speeding. With a ticket it is quilty to proven innocent.
Chuck