H2S, Navigation & Bombing
H2S is a radar device carried in aircraft to reproduce, on a cathode ray
tube, a picture of the area over which the aircraft is flying. The centre of the
display will always represent the point on the earth's surface directly below
the aircraft. The operator is thus enabled to:
- Fix his position;
- Determine range and bearing of built up areas;
- Home on target for blind bombing.
By means of a second cathode ray tube and an associated marker and control
the height of the aircraft above the earth's surface can be determined.
When the appropriate adjustments have been made the ground speed of the
aircraft can easily be determined from the movement of the indications across
the main H2S display.
If an additional unit known as "Lucero" is in the installation, the
equipment can be used for homing on long range beacons and blind approach runway
beacons.
In 1943 another indicating unit, known as "Fishpond", was
introduced. "Fishpond" could show range, and
azimuth of aircraft appearing on a hemisphere below the aircraft. The centre of
this hemisphere will be at the aircraft and the radius of the hemisphere will be
equal to the aircraft height.
The H2S installation with Lucero and Fishpond is therefore:
- An extremely versatile navigational aid;
- A blind bombing aid;
- A warning device which can give warning of attack from enemy aircraft,
provided the attack is made from below.
Aside from Lucero applications the equipment is self-contained in the
aircraft and is therefore not subject to the range limitations inherent in
equipments dependent on ground transmissions.
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| Map display |
H2S display |
H2S Mk 1
H2S Mk 2
H2S Mk 2A
H2S Mk 2B
H2S Mk 2C
H2S Mk 3
H2S Mk 3A
H2S Mk 3B
H2S Mk 3C
H2S Mk 3D
H2S Mk 3E
H2S Mk 3F
H2S Mk 3G
H2S Mk 3H
H2S Mk 4
H2S Trainer type 54
H2S Mk 1
| Year of issue |
1942 |
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| RAF designation |
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| Frequency |
2900 MHz, 10cm |
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| Main items |
Transmitter
Transmitter
Modulator
Waveform generator
Switch unit
Receiver timing unit
Indicator
Heading control unit
Junction Box
Scanner
Power unit
Voltage control panel |
TR 3190
TR 3191
type 64
type 26 (or 27)
type 207B
R 3515 (or 3516 or 3518)
type 162 (or 163A)
type 218
type 83
type 3 (or 51)
type 224 (or 280)
type 5 |
| Remarks |
experimental, 200 produced |
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H2S Mk 2
| RAF designation |
ARI 5153
ARI 5560, including fishpond. |
| Function |
ARI 5560 is an airborne radar equipment
used an same Bomber and Coastal Command aircraft. The installation
includes all the units of ARI 5153 (H2S Mk. 2 and 2A. ASV Mk. 3A and
3B) and an additional unit for the detection of aircraft in the
vicinity. The additional unit is auxiliary to the main equipment and
is an indicator designed to present part of the normal PPI map in a
form suitable for the detection of aircraft. The additional
indicator displays in PPI form the volume swept by the ARI 5153
scanner between the aircraft and the ground, i.e. it covers what can
be regarded as the "hole" in the original ARI 5153 PPI map |
| Year of issue |
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| Wavelength |
9,1cm S-Band |
| Pulse width |
1 microsecond |
| Pulse recurrence
frequency |
670 p.p.s. (approx) |
| Range scales |
10, 30, 50, 50 to 100 miles |
| Power supplies |
14Volt aircraft supply and 80 volt Ac
supply to power unit 224 or 280. |
| Main items |
Transmitter
Modulator
Power unit
Waveform generator
Switch unit
Receiver timing unit
Indicator
Aerial system
Junction Box
Scanner
Generator
Junction box
Mark III IFF set
Lucero Mk I or
Lucero Mk II
Lucero aerials
Voltage control panel |
TR 3159 (or TR 3191)
type 64
type 280 (or 224)
type 26 (or 27)
type 207
R 3515 (or 3516)
type 162 (or 163)
type 307 (or 178)
type 218
type 51
type U and KX or UKX
type 83 (or 206)
R3090
TR 3190
TR 3160
type 301
type 5 |
| Remarks |
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H2S Mk 2A
| Year of issue |
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| RAF designation |
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| Frequency |
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| Main items |
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| Remarks |
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H2S Mk 2B
| Year of issue |
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| RAF designation |
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| Frequency |
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| Main items |
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| Remarks |
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H2S Mk 2C
| Year of issue |
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| RAF designation |
ARI 5590 |
| Frequency |
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| Main items |
Transmitter
Modulator
Power unit
Waveform generator
Switch unit
Receiver timing unit
Indicator
Tuning unit
Heading control unit
Junction Box
Scanner
Amplifier
Track marker control
Scanner speed control unit
Gyro control unit
Motor generator
Junction box
Stabilised platform
Main junction box
Fishpond indicator
Fishpond junction box
Fishpond bright up WFG
Lucero Mk II
Lucero control unit
Lucero aerials
Voltage control panel
Alternator |
TR 3191 (or TR 3159)
type 64
type 280 (or 224)
type 34 (or 35)
type 207B
R 3515 (or 3516)
type 184 (or 184A)
type 207
type 446
type 247
type 63
type A3562(RPU)/A3562A(Gramco)
type 468
type 477
type 453
type 74
type 246
type 26
type 83
type 182 (or 182A)
type 222
type 43
TR 3160
type 222A
type 184
type 5
type U |
| Remarks |
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Click here for the
interconnections diagram of the ARI 5590
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H2S Mk 3
| Year of issue |
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| RAF designation |
ARI 5564 |
| Frequency |
9600 MHz, 3cm |
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| Main items |
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| Remarks |
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H2S Mk 3A
| Year of issue |
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| RAF designation |
ARI 5583 |
| Frequency |
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| Main items |
Transmitter
Modulator
Power unit
Waveform generator
Switch unit
Receiver timing unit
Indicator
Tuning unit
Heading control unit
Junction Box
Scanner
Amplifier
Track marker control
Scanner speed control unit
Gyro control unit
Motor generator
Junction box
Stabilised platform
Main junction box
Fishpond indicator
Fishpond junction box
Fishpond bright up WFG
Lucero Mk II
Lucero control unit
Lucero aerials
Voltage control panel
Alternator |
TR 3555B (or TR 3555C or TR 3555A)
type 64
type 280 (or 224)
type 34 (or 35)
type 207B
R 3553 (or 3554)
type 184 (or 184A)
type 444 (or 499)
type 446
type 247
type 71
type A3562(RPU)/A3562A(Gramco)
type 468
type 477
type 453
type 74
type 246
type 26
type 231
type 182 (or 182A)
type 222
type 43
TR 3160
type 222A
type 184
type 5
type U |
| Remarks |
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Click here for the
interconnections diagram of the ARI 5583
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H2S Mk 3B
| Year of issue |
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| RAF designation |
ARI 5793 |
| Frequency |
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| Main items |
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| Remarks |
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H2S Mk 3C
| Year of issue |
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| RAF designation |
ARI 5716 / 5717 |
| Frequency |
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| Main items |
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| Remarks |
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H2S Mk 3D
| Year of issue |
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| RAF designation |
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| Frequency |
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| Main items |
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| Remarks |
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H2S Mk 3E
| Year of issue |
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| RAF designation |
ARI 5705 |
| Frequency |
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| Range |
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| Main items |
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| Remarks |
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H2S Mk 3F
| Year of issue |
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| RAF designation |
ARI 5698 |
| Frequency |
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| Main items |
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| Remarks |
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H2S Mk 3G
| RAF designation |
ARI 5747 |
| Function |
H25 Mk. 3G is fitted in aircraft to give
a plan position indication of the area over which the aircraft is
flying. The Mk. 3G has been derived from the Mk. 3A by the removal
of the roll-stabilization mechanism and also by the addition of a
PPI indication on the range scale switch 100/40-80. Height
indication is given on a separate cathode-ray tube |
| Year of issue |
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| Wavelength |
3 cm |
| Type of wave |
pulse |
| Pulse width |
1 uS |
| Pulse recurrence frequency |
670 per sec. |
| Peak power output |
30-40 kW |
| Power Supply |
180Volt 2000c/s
28Volt DC Aircraft supply |
| Main items |
Transmitter
Modulator
Power unit
Waveform generator
Switch unit
Receiver unit
Indicator unit
Tuning unit
Heading control unit
Junction box
Scanner unit
Amplifier unit
Track marker control unit
Scanner speed control unit
Fishpond indicator
Fishpond junction box
Fishpond bright-up WFG
Lucero Mk2
Lucero control unit
Lucero aerial
Voltage control panel
Alternator |
type 3555B (or 3555C or 3523A)
type 64
type 280 (or 224)
type 65
type 289
type 3653
type 184 (or 184A)
type 444 (or 499)
type 446
type 247
type 71
type A3562 (RPU) (or A3562A (Gramco))
type 468
type 477
type 182 (or 182A)
type 329
type 43
TR3160
type 222A
type 184
type 5
type U |
| Remarks |
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H2S Mk 3H
| Year of issue |
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| RAF designation |
ARI 5746 |
| Frequency |
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| Main items |
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| Remarks |
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H2S Mk 4
| Year of issue |
1943 |
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| RAF designation |
ARI |
| Frequency |
3cm |
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| Main items |
Indicator unit
Transmitter
Scanner unit |
type 300
TR 3523
type 109 |
| Remarks |
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H2S Trainer
type 54
| Use |
H2S Ground training equipment. |
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| RAF designation |
trainer type 54 |
| Main items |
Indicator unit
Switch unit
Control unit
Table recording unit
Junction box
Power unit
Waveform generator
Receiver unit
Modulator unit
Control unit
Follower unit
Scanning unit
Power unit
Power unit
Rack assembly |
type 197
type 207
type 218
type 2
type 217
type 224
type 26
R 3515
type 167
type 425
type 51
type 54
type 548
type 549
type 108 |
| Remarks |
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