RCA BTA-5G Transmitter
To save confusion it is probably best to first get a better understanding of the two smaller transmitters that were used on the Ross Revenge, in particular how and when they featured during Radio Caroline's broadcasting years at sea.
When the Ross Revenge was fitted out as a radio ship three transmitters served the ship during its broadcast years from 1983 to 1991;
RCA Ampliphase (50kW unit)
and BTA-5G (5kW)
It was always the intention that the 10kW transmitter would be the standby unit for the Ampliphase should it be required. However as you have seen from previous pages this changed when Radio Monique co-habited with Radio Caroline, the result being that Monique rented the 50kW transmitter and Caroline assigned themselves the 10kW transmitter.
The RCA BTA-5G transmitter, at the time of installation, was non-operational with many missing parts. It wasnt until 1985 when another 10kW was sourced for spare parts which enabled the 5kW transmitter to be made operational ... and also provided spares for the 10kW unit.
All three transmitters suffered at the the hands of the fateful raid on the Ross Revenge in 1989 and were stripped of anything useful to prevent transmissions. The 10kW in particular was robbed and sustained the most damage during the raid, however both the 50kW and 5kW units were at least repairable. The 10kW unit still sits in the shadows starboard side behind the Ampliphase 50kW transmitter, and whilst it is unlikely that this transmitter will ever be used again, it does however act as a sad reminder to bygone days.
Visually it is almost impossible to distinguish the 5kW unit look from its 10kW counterpart. It has the same 'accordion' style doors and also has the same four cabinet configuration which house the various stages of the transmission process;
i) Audio Stage / Modulator
ii) RF - PA Stage
iii) Oscillator / RF Driver Stage
iv) Rectifier / Control Stage
Both of the smaller transmitters were built in the early 1950's and the main differences between the 5kW and 10kW units is the inclusion of an additional RF PA tube and an upgraded modulator driver stage on the 10kW version
As was the case with all transmitter cabinets capable of carrying thousands of volts, the BTA-5G was provided with door interlocks which prevented the engineer working on the unit from accessing the final stage cabinet which was capbable of producing voltages in exceess of 15,000v.
Download Section - RCA Transmitters
Radio Caroline / Radio Monique Diplexer | Ampliphase BTA-50H (50kW Transmitter