Romeo romeo you are probably right, the biggy must certainly get a radar service like you ask for but only as longt he radar service is not limited due to poor radar performance or limited radar coverage (happens everyday).
- I am not too familiar with the sheffield area so the following may not apply but wherever you are, Class G remains class G with its rules and responsabilities. ie the controller can't do much to help you.
Using a personal and daily experience, when I descend towards Filton, I usually get a sqawk 50 miles inbound with a RIS from Radar. Great you think but not that great because as it happens, I fly near Gloucester at a relatively low altitude and there is nothing that tells me how much traffic there is in the area at that time. Filton is only aware of people who talk to them, not the gloucester traffic manoeuvring at various height. Of course It is good idea to inform Gloucester of my presence (usually about 20 miles West) but it is if I have the time for it and again only 100% useful if they have been made aware of any activity.
My points are:
-Do not assume that ATC knows all about every traffic in the sky. They simply don't.
As a matter of fact my ex house mate is an ATCO which allowed me to realise how little there is they can do if we don't do our bits (and know the rules, limitations and pilot/ATCO responsabilities). Very scary how much I took for granted
-Class G is scary as hell and I try to avoid it as much as possible
but that is because I can.
-Flying IMC without radar service (RIS or RAS) seems rather risky (my own perspective)
-As for TCAS, not that CessnaEng said otherwise but just as a reminder, It only works with Transponder Mode C SELECTED.
Good night