Yes, Rebecca 8 antennae. A DME system operating at around 220 MHz; you selected the code on a big bakelite box (one clunky rotary selector for each part of the code - letters for the 'Tx' part and numbers for the 'Rx' part) e.g. C4 for Cranwell and D5 for (I think) Cottesmore. Then listened for the coding - because it was't uncommon for the wrong station to have been tuned in, despite the selection made! The indicator in Vampires, JPs and Hunters was a single needle against a range scale with a 'homing' section which could only be used at short range - when the needle was centred you were either pointing directly at the station or directly away from it. We only used it the 'homing' part for DME letdowns, e.g. when inbound on the final approach. QGH to the overhead, then a dead reckoning descent in the 'safety lane', before flying the final approach on DME was a lot easier! Quite a few sessions in the Link Trainer to practise though!
For normal fixing above cloud, we usually used UHF/DF and Eureka/Rebecca; if out of Eureka coverage, a couple of bearings from different stations was fine. Of course there were enough RAF stations around to make that feasible back then. Although we were still without transponders or navaids and using DF/DF fixing in IMC or above 8/8 in HM's Bulldogs in the late 1980s until we were given the magic of VOR/DME/ILS, a multi-channel UHF radio and a transponder.
Eureka / Rebecca disappeared when the Hunter went out of service, if memory serves correctly. Eureka stations were marked on the En-Route Chart as small black blobs with a white 'E' and the legend 'Eur7'.
When the JP 5A first appeared, occasional vibration would be noticed in cloud. Something of a mystery....
Until one day, Geoff St*****l had something go seriously 'twang' in the fin of Finningley JP5; fortunately he managed to lend it safely (at Llanbedr?).
It was found that the fin-mounted VOR antennae picked up ice and could vibrate at sufficient amplitude to fatigue the fin. The LLADTS Finningley Mk5s were probably fleet leaders as regards fatigue, hence Geoff's incident.
The solution was a couple of wires from fin to each antenna tip to stop them moving.