Landlubbers ahoy!  An input resistance to die for...

Classic Marconi Oceanspan MF spec:

Measured into an artificial aerial load with the following constants :

Capacity                              300 uuF

Resistance                           3.6 ohms

CW (A1)                               65 Watts  at  4.2 amps approx

MCW(A2)                             72 Watts  at  4.5 amps approx

 Aerial  Characteristics

The transmitter is designed to work into an aerial with the following characteristics :

Medium Freq

Main aerial                       410 -  512 khz              300 - 750 uuF +  1.9 - 10 ohms

Emergency aerial               500 khz                     200 - 400 uuF +   1.9 - 10 ohms

As an approximation, the aerial capacitances given above would be equivalent to the following aerial lengths:

Main aerial                                                               150 - 330 feet

Emergency aerial                                                      90  -  170 feet.

end.

Class I ship:

Main Tx:       102 metre-amps:   Range 175 nautical-miles.

Reserve Tx:     76 metre-amps:  Range 150 nautical-miles.

QTO,

Rog.