Basic Service
Provides advice and information useful for the safe and efficient conduct
of flights. e.g. weather information, changes of serviceability of facilities,
conditions at aerodromes, general airspace activity information, and any
other information likely to affect safety.
Provision: ATC and FISO
Flight Rules & Met: VFR and IFR, VMC and IMC
Identification: Possibly, but does not imply radar service
Traffic & Deconfliction: Not specific
Terrain Clearance: Pilot responsible
Headings & Levels: Not required to notify, No specific control
Note: Allocation of a squawk does not imply a radar service
My best piece of advice is to buy a transponder; they're not an arm and a leg nowadays. If you spent a while sitting with a Farnborough radar controller, or similar, on a busy Sunday or Bank Holiday you'd rush out and buy one next day!