how to get 5.2 volts

[Kyo]

does it really need to be 5.2? is there no tolerance? Have you tried using 5V?

[collinE]

the 7805 only outputs 1 amp so if your needs are higher than that, you should do two.

[OMGpedobear]

put a 1W to 5W 10 ohm resistor on the output of the regulators if your put them in parallel, stops the stronger regulator taking all the load and dying (such courageous hard working soles are 7805's , they'll die for the purpose of regulation), ignore that.

Your not going to do any damage under volting so start low and work up until 12 volts, i cant think of any application where 0.1 volts means killing an ic, if its serial your using , that is rather fussy on 5 or 10 volts , so if your using 10 volt serial , don't go feeding it 10.9.

[OMGpedobear]

just had a thought, if you get a really fine trim pot and wire it up to an adjustable 8 pin ic voltage regulator you could probably get around a consistent 10.9 volts.