How did you use it?
You angled your radar to look in one piece of sky - usually on the nose, with a search either side of your heading, angled up or down by a number of degrees - or using aircraft software to search a particular height band at a certain range. Hopefully you had a friend nearby to search the bit you were missing. So in an example a pair of fighters would commit off towards a contact, as detected by someone else, each looking 20 degrees either side of track and one looking low, the other looking high.
When one got a contact he would tell the other, but you would maintain the radar posture so no one else could leak through. In the Sea Jet a designated track would look like a block on the radar screen with a small stick showing where he was going. At the bottom of the screen you would be shown his heading, height, speed etc. You had a set of target markers (think mouse but controlled with left thumb) and by them would be a digital read out of the height you were scanning.
So you could, for example, be contracted to scan from surface to 20k at 20 miles - but have a detection at 30 nm, and as your altitude was 35k your target marker would say something like 10 k to surface when you put it over your radar contact.
The automatics could trick you because they would want to scan centre on the contact whereas your job was to scan airspace until such a point as you bit the bullet and intercepted that particular chap - with tactics varying depending on who he was and what you actually wanted to do.
Most radar displays were/ are similar. Little tadpoles showing tracks, blocks showing un correlated hits, lines showing interference.
The F3 had an A scope I think - that I was shown in debriefs but it had a utility I didn't understand.