do record mats work

yes i had it set up by a good repair shop it seams like hum gets louder as the needle goes to the middle of the record allso tryed other cables the first one grounded out whhen you touched it think it was less insulited

I was thinking you were talking about vibrations from motor rather than electrical hum; I can't see how a mat helps that. Have you tried grounding your table to the center screw on an AC outlet? I also use to use a cheater plug to reverse the wall connection. Hum problems are notoriously difficult to deal with. I would look on Audio Asylum to see if anyone else has had this problem.

I used on to damp the 'ringing' of the platter of a Pioneer TT. That wordked fine. Never used them to diminish hum though.
Keep in mind that you'll have to adjust the VTA (Vertical Tracking Angle) of your cartridge if the replacement mat is thicker or thinner then the original mat.

Let me guess. You are using a Grado cartridge?

Anyway, what you describe is probably caused by the cartridge picking up EMI from the table's motor. NO platter mat is going to help with that.

I believe Dan ed has it correct!