460 PROPAGATION THROUGH 
whether set performance is normal. The curves 
can be used for this check by using a known ship. 
Such:a check is shown in Figure 9 for two different 
days. On one day, the points for the ship fell in 
the correct region. On the other day, they fell too 
low by about 20 db. Accordingly, on the latter day 
the curves should have been used with an ordinate 
correction of —20 db. 
Other types of performance check may be used, 
THE STANDARD ATMOSPHERE 
such as permanent echoes, free-space range of air- 
craft, or a signal generator. 
DATA ON EQUIPMENT 
The tables given in this section are not intended 
to be exhaustive. These are the best available data 
but should be used with caution, since specification 
changes may change rated characteristics of sets. 
Tasie 3. Communication equipment. 
Power Antenna 
Communieation Frequency output Receiver Polarization Gain Beamwidth 
equipment (mc) (watts) sensitivity (db) Horizontal Vertical 
SCR-608 30 25 0.2 uv V Whip 
SCR-300 44 0.5 2.5 Uv Va Whip 
AN/TRC-1 70-100 50 25 uv H 6 
(4 channel) 
SCR-522 125 6 4 pv 4 Whip 
AN/TRC-8 240 12 30 LV H 7 
(4 channel) 
AN/TRC-5 1,400 400 NF* 12 db H 14 
AN/TRC-6 4,600 2 NF* 19 db H 33 
TBS 70 50 5 pv V 1 
AN/ARC-1 125 10 5 uv V Whip 
* Noise figure. 
TaBLE 4. Radars. 
Receiver 
Power sensitivity 
Frequency output Noise figure Bandwidth Antenna Beamwidth 
Radars (me) (kw) (db) (me) Polarization Gain (db) Horizontal Vertical 
SCR-271DA 106 100 6 1 H 19.8 11° 12° 
AN/TPS-3 600 200 11 1.8 H 23.4 12° 11° 
SCR-584 3,000 300 15 1.7 H 30.8 7° a 
AN/MPG-1 10,000 60 17 10 40.8 0.6° 3° 
SC-4 200 200 6 0.5 H 13.5 20° 60° 
SQ 2,500 1 13 2 V 20 8° 15° 
SG-1 3,000 50 18 1 H 28 6° 15° 
ASB 515 10 15 1.4 H 30 60° 
Taste 5. IFF or beacons. 
: Antenna 
Frequency Power Receiver Polarization Gain 
IFF or beacons (mc) output sensitivity (db) 
AN/TPX-4 170 0.5 kw 15 Hv V 6 
AN/UPN-1,2 3,000 50 kw 0.05 Lv H 6 
AN/UPN-3,4 9,320 300 kw 0.02 HV H 12 
