Is there an iOS that won't install new baseband?

[Phenith]

I have an iPhone with baseband 4.26 but only iOS 3.0... is there an iOS I can install that won't upgrade my baseband?
I'm not concerned about going all the way to 4.2.1.
Or do I have to use tinyumbrella to upgrade without losing my baseband?

 

[Dj101]

google knows

Upgrade iOS 4.2.1 on iPhone 4 with TinyUmbrella Without Upgrading Baseband | Jaxov