Protection diodes with less voltage drop?

[garfo]

Hi guys.
Trying to figure out a way of using a diode in series with the rail with the potential of losing the least voltage possible when powering from a 9v source.
The diode being used at the moment is a 1n4001 but that drops the voltage a bit and it would be good to try and keep the voltage as close to the source as possible when using it in series.
Hope someone will have some helpful information on this.

Thanks

[mjg]

Try a 1n5817?   They have less drop than the 4001.