Same radar different mounts for two totally different ships, the data and info I have passed on comes from the guys who served on Tiger
Bob
Here's a video of a Harrier taking off from Blake, where you can see the 278 rotating through 360 deg:
https://imgur.com/gallery/HyT39TMThe link to the video came from this site, which has a great article on the Tigers, complete with lots of big, clear photos (if you download them):
https://www.navalanalyses.com/2016/08/warships-of-past-tiger-class-cruisers.htmlDoing a bit of reading, it seems that the 278 was a modernised version of the 277Q, which dated back to WWII, with new components to improve reliability, but working in the same way. 277 (of which 277Q was an update) was primarily an air/sea-search radar, which only started to be used in a height-finding role later. Air/sea search radars scan, by rotating 360 deg, by definition. There's a scan rate in the specs: 16rpm max. A system to
stop the scanning had to be added later in order to do height finding.
There aren't many good online sources for info about radar unfortunately (at least that I've found). Wikipedia doesn't have an article on the 278, but it does have a long and well-sourced article on the 277 here:
https://en.wikipedia.org/wiki/Type_277_radar#P_and_Q_modelsFrom that article:
"The
Type 277 was a
surface search and secondary aircraft
early warning radar used by the Royal Navy and allies during World War II and the post-war era."
"The 277 used a 500 kW magnetron... and added a
plan-position indicator (PPI) system with several remote displays."
"The resulting system, Type 277Q, arrived too late for Project Bubbly and did not see service until the post-war era. In tests aboard HMS Illustrious in March 1947, 277Q provided reliable
detection in the TI role out to 85 miles (137 km) and heightfinding to 55 miles (89 km), dramatic improvements on the 293."
The 'TI role' mentioned is Target Indication, which basically means 'air-search with enough precision to point weapon systems'.
Why would a pure height-finder use a PPI (Plan Position Indicator: the classic 'radar scope'), which is designed to show a map-style 360 deg view around the ship?
Speculation: (I have no evidence for this, it just makes sense to me) The Type 278 was
mostly used as a height-finder on Tigers, so it was
usually stationary. However, at times when they didn't want to use the big Type 965, for instance when close to other ships or helicopters whose crews they didn't want to fry, they swtiched the 965 off and used the 278 in it's search mode instead. I know the 965 is rotating in the video, but just because it's turning, doesn't mean it's transmitting: the Type 1010 IFF (Identify Friend or Foe) transponder is mounted on top of the 965 aerial, so that'd be reason enough to keep it going round.
ANYWAY, taking my 'obsessive geek' hat off for a minute, the object of the exercise here is to help Chris build his model, and the good news, as far as I can see, is that there isn't a
wrong way to build the 278! Rotating, still, turning back and forth at random, it's all good.
Stay Safe,
-Harold