Serrate radar detector
Serrate was an Allied radar detection and homing device, used in Allied nightfighters to track German night fighters equipped with the earlier UHF-band BC and C-1 versions of the Lichtenstein radar during World War II.
No. 141 Squadron RAF, commanded by Wing Commander J. R. "Bob" Braham and flying the Bristol Beaufighter, commenced operations over Germany in support of the Bomber Offensive from 14 June to 7 September 1943. 179 operational sorties yielded 14 claimed fighters shot down, for 3 losses.
The Serrate equipment could detect bearing and elevation/depression but not range. Using Serrate, a bearing/altitude to fly was obtained then forward looking radar (AI Mk. IV radar) used to capture the target and attempt interception. As these two pieces of equipment shared the same two display tubes they could not be used at the same time.
The technique described here is for the Monica tail warning radar: The technique developed was for the RAF nightfighters to fly slowly off the bomber stream, mimicking the characteristics of a heavy bomber, until the rearward-facing Serrate (Monica) detector picked up the emissions from a Luftwaffe night fighter approaching. The Radar Operator would then pass directions to the pilot until the fighter was 6,000 feet behind, at which point the Beaufighter would execute a swift turn onto the tail of the German night fighter, pick up the enemy aircraft on his forward radar and attempt to down it.
Serrate was also subsequently fitted to de Havilland Mosquito nightfighters.
No. 141 Squadron transferred to No. 100 Group Bomber Command in late 1943 and during the Battle of Berlin on the night of 16/17 December, a Mosquito crewed by Squadron Leader F. F. Lambert and Flying Officer K. Dear made Bomber Command's first successful Serrate-guided operational sortie when they damaged a Bf 110 with cannon fire. The Serrate night fighter offensive preceded far greater and wide-ranging support operations by the specialist 100 Group during 1944-45.
- List of World War II electronic warfare equipment
- Air interception radar in World War II night fighter aircraft 
- Staff. Campaign Diary December 1943, Royal Air Force Bomber Command 60th Anniversary web site. Retrieved 11 August 2008