The Jet Provost Mk3's and 4's also had Rebecca Mk8 fitted, our JP4 XS186 had Rebecca re-fitted as art of it's restoration a couple of years ago, and we have been pleasantly surprised to see that on switching on, a reading of 12 miles is shown to the beacon......and the tone in the headset is strong.....
It would probably get a few of the old timers all teary eyed.
If you want aerial dimensions I can measure them up for you at the weekend?