I cannot get my radio to work on a 51 ford focus

If it is nothing obvious like a fuse or bad connection then one  way of proving it is by using a multi-meter or a test lamp to prove that the + and  - (battery and chassis/earth) supply is available to the radio.

Another method is to try your radio in ANOTHER  car (or on a workbench )      and/or try another radio in YOUR car.

This will prove whether the problem is the radio or the battery supply or your car wiring.