Letter from Bruce T. Neale, Marconi Radar Systems Ltd., to Martin Shough 10 Nov 1986
Marconi Radar Systems Limited
Writtle Road
Chelmsford CM1 3BN
Telephone: 0245 267111 Telex: 99108 Facsimile: 0245 357927
Ext.2268
Ref. BTN/VGD
10th November 1986
Dear Mr. Shough,
Apologies for delay in responding to your letter dated 31.10.86.
I was hoping to send the handbook as promised, but unfortunately
have run into a snag. M.O.D. have refused to give their OK on the
grounds that the A.P. is still classified! (Restricted) If you
have any friends who have connections with M.O.D. Security, the A.P.
number is 115H-1300/1400-1 entitled Radar Type:13 (Mk.6 and 7)
and 14 (Mk.7, 8, 9 and 10).
However, to help with your research, I have summarized the
parameters of the Type 13 and 14 as follows:-
1. Type 13 (Height finder) Mk 7
Frequency: 'S' Band (IOcms).
P.R.F; 250 or S~Op.p.s (depending on role)
Vertical Beamwidth; approx 1°(parabolic)
Horizontal Beamwidth; approx 4°
'Nod' Angle; 21°
'Nod' Rate; 6 nods per min (?)
Antenna dimensions; 20 ft by 5ft 6ins. fed by slotted waveguide
Transmitter Peak Power ;approx 500KW (Magnetron)
Pulse length; 1.9 microseconds
The antenna is 'azicated' onto target by the operator who
controls the bearing by means of a servo mechanism from the P.P.I.
Console.
The height range console is usually calibrated 100 to 150
miles but its detection range will obviously depend on the radar
cross-section of the target.
2. Type 14 (Surveillance) Mk 7 and 9.
Frequency: S .Band
P.R.F.; 250 or 5~0pps (usually 250pps)
Horizontal Beamwidth; approx 1° (parabolic)
Rotation Rate: 0 - 6RPM (normally operates at 6RPM)
Peak Power and Pulse Length as for Type:14 [sic. "14"
should read "13"] (Note: The cabins are identical with
the Type 13 Mk.7)
The range performance depends on target cross-section, but the P.P.I,
is usually set up to 150 miles.
3. Type 14 (Surveillance) Mk 8
As for Mark 7 and 9 but antenna profile shaped to give a Cosec2
cover diagram (Fan beam) for high cover.
4. Type 7 (Surveillance)
Frequency; 200 MHz (metric)
P.R.F.; 250p.p.s
Peak Power; approx 500KW
Pulse length; 3.8 microseconds
Antenna Rotation Rate; 0 - 6 RPM (usually 6)
Antenna Type; 8 bays of stacked full-wave horizontal dipoles,
switched for height finding, to compare signal amplitudes from
the vertical lobe structure due to ground reflections. (It was in
fact a '3D' System!).
Description of typical G.C.1. ("Happidrome")
Station
The 'master' radar was the Type:7.. A Type 14 Mk.7 and a Type 14
Mk.8 were synchronised in turning by a servo system at a rate of
6 RPM. The Type 14 Mk.7 with the parabolic beam shape 'looked' in
the same direction as the Type:7, and the Mk.8, with the Cosec2
beam 'looked' 180° off beam (ie. the reciprocal bearing). No
distinction was made as to which radar was used for interception,
all radar data was fed to the various consoles and was
selectable, the choices were: Type:7 only, Type:14-Mk.7, Type:14-Mk.8,
Type:7 plus Type:14-Mk.8 (automatically switched over a
selectable sector of 180°). In general, the Type:7 was the main
radar, the Type:14-Mk.7 was a 'low-cover' gapfiller and the Type:14-Mk.8
was for high cover. The controller/operator made the best use of
the available data to suit a specific situation.
Two Type:13's were used to supplement the height finding of the
Type:7. The Type:13 was 'laid-on' (azicated) by the operator by
bisecting the target on the PPI by an 'intertrace' marker and the
height read from an adjacent height-range console.
I have sketched a rough layout
to the best of my recall and enclosed photographs of a Type:14
and Type:13.
I hope this brief data will suffice. Should you have any further
questions, please call me on Chelmsford (0245) 26711 either on
Tuesdays or Thursdays.
Yours sincerely,
For and on behalf of THE MARCONI COMPANY LIMITED
s/s BRUCE NEALE
Consultant ~
Marconi Radar Systems Limited
Enc: Photographs
Sketch