I fly from NW and we don't usually bother talking to Essex Radar, just go straight to Elstree Info. As it's such a short flight from Elstree, changing straight over will give you a chance to hear if there are any jets in the circuit. (There are often Jet Provosts and Gnats flyig, with also a chance of a Hunter and Venom - also the newly based Mustang Jumpin Jacques)
On Saturdays there is the market, so runway 13/31 is unavailable (except for take offs on 31). Main runway 02 LH /20 RH circuits.
Coming from Elstree, aim for joining downwind at Epping if they are using 20 or left base for 02.
If using 20, we normally turn base over the M11 motorway junction at Harlow, which keeps you well outside the Stansted zone.
Enjoy your visit.
RD
