3.
20
Shanghai
the Transmitter will be the same as used for much longer
distant circuits and have ample power available.
will probably use a Standard Telephone & Cable Co's
Type II Transmitter. The distances are 700 miles
(Shanghai) and 625 miles (Manila), the former over coast
land and the latter over sea.
Under the circumstances, it is proposed to
commence with horizontal dipole receiving aerials of
optimum heights, but it is suggested that contractors be
requested to supply constructional details for Double
Horizontal Dipole and Series Phase Arrays, whilst only
supplying, at present, materials for simple Dipole and
harmonic aerials in accordance with our Indent.
(6)
Frequencies.
It is proposed to use 9244 Kilocycles (32.45
metres) for the normal transmitting wavelength, with 4622,
13866 and 18488 Kilocycles (harmonically related) available
in addition. Due to the rather abnormally high noise
level experienced at times on frequencies below 12500 Kc/s,
it is frequently found that 13 to 15 Megacycles are more
suitable even at these comparatively short distances.
The highest frequency will not normally be used, except for
any long distance tests that we may decide to make.
Manila will normally use his KAZ Transmitter on
9990 kc/s (30.03 metres) and Horizontal Dipole Antena,
except during early morning (8 to 10.30 a.m.) when his KAY
San Francisco Beam Service may be utilised on 20.03 metres.
Shanghai will probably use a Standard Telephone & Telegraph
Co's Type II Transmitter on a terminated dipole transmitting
antena. His frequency has yet to be fixed, but will
probably be approximately similar to ours. His new
Marconi Beam Transmitter may possibly be available on
Franklin Uniform aerials, during certain hours, but this
Page 20Page 21