Changing the Hash algo in gpg1.2.3

[Admin @ Petridish.org]

I am sorry I sent this on another thread by mistake.  Please forgive me (won't happen again) 
(posting b4 coffee)

here was my question, now that it has a more aptly named title

Hello, 

I was wondring if someone could point me to an online doc on how to set a different hash algo in gpg
I spent a while sniffing around on the net - to no avail.  

If there isisnt a manual or faq that explains it, would someone mind laying out a thumbnail sketch of how to do it? 

I have heard that sha1 has been broken and I wanted to begin using md5


-respectfully 

john