If two or more people are talking, you can record it as long as YOU HAVE CONSENT of at least one party member. If you are one of the party, then of course you have your own consent. Therefor it is not eavesdropping.
Possession of an eavesdropping device requires intent to eavesdrop. If you are intending to protect yourself with the use of a recorder, that is not eavesdropping.
If you are installing a recorder or other device for the purpose of listening to other peoples' private conversation, then you are eavesdropping. If it is a conversation you are privileged to the conversation or have any other kind of consent then you are not eavesdropping.
Long story short, if you have access to the conversation in person then you can legally record it as you are a member of the conversation.