Does jammer only jam your location only and not your teammats? (That's silly since it's in the Teamplay catergory when you Research it).
Also if both you and your opponent have jammer and detector, does that mean you won't be able to know each other's location? Because I have jammer and a teammate has detector, but then suddenly there are a few enemies appearing in front of me which wasn't detected.
Jammer only conceals you. Yes, the category is a bit odd, but I suppose MF wanted less pages of weapons with more content on each and couldn't find a better classification.
Correct on the second part. You will not be able to see your enemy on radar nor can they see you. Jammers block out the equipped player on both radar mk1 and radar mk2 for all enemy radars. (Still visible to teammates if anybody is wondering.)
Keep in mind the roommate's radar is also limited to a range around them. I sometimes do recon at or behind enemy lines with radar and jammer, using silenced Maurauder and commanding teammates when to move up with quick command icons.