Fencer
Experimentalist
On long trips I usually ask for VFR radar services and I was never refused. Sometimes I fly without talking to ATC but I always monitor corresponding frequency.  
 
Peacefully sitting on 10.5 minding my own business on the way from FL. Center to somebody - Sheetakwa XXX traffic 12 o'clock 7 miles north bound 10.4 indicated report in sight. OK, everybody happy.
 
In 10 minutes, still in the same sector, I believe the same controller to other aircraft - CommuterXXX traffic 1 o'clock type and altitude unknown... (????) I was his traffic and saw him, he never saw me but reported on fish finder.
 
Why different answers? Is there a radar inability? Unreadability? Other reasons not to give him my alt and heading?
				
			Peacefully sitting on 10.5 minding my own business on the way from FL. Center to somebody - Sheetakwa XXX traffic 12 o'clock 7 miles north bound 10.4 indicated report in sight. OK, everybody happy.
In 10 minutes, still in the same sector, I believe the same controller to other aircraft - CommuterXXX traffic 1 o'clock type and altitude unknown... (????) I was his traffic and saw him, he never saw me but reported on fish finder.
Why different answers? Is there a radar inability? Unreadability? Other reasons not to give him my alt and heading?