CO129-510-21 Hong Kong and Canton wireless service- report- and recommendations 7-8-1928 - 7-8-1928 — Page 38

3.

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transmission is to be satisfactory. This point has also a

big effect on the life of valves: the difference between

5% regulation and 1% effects the life of the valve to the

extent of about 50%. This fact alone justifies the purchase

of voltage regulators and accumulators, etc.

8. Short Wave transmitter. It was observed that the

circuits used in the Canton transmitter were very closely

coupled to aerial, and the oscillating circuits were not

controlled. It is advisable to reduce the coupling and work

with controlled oscillators.

9. The receivers in use were unscreened. With a

number of such receivers in use in close proximity to one

another there would be a risk of mutual interference.

It

is desirable that all receivers be carefully screened, and

their circuits designed to eliminate oscillation.

10. With the establishment of central transmitting and receiving stations, duplex working will be possible, and in laying out the receiving gear sufficient bench room should be allowed for two operators to be employed adjacent to one another so that the sending operator can speak to the receiving operator.

11. The installation of "Facsimile" transmission, or photo telegraphy, has been suggested. Investigation as to price and working is being made and a further report on this matter will be forwarded. It should be noted that no system of "Fassimile" transmission will be successful unless the medium used for transmission is absolutely steady and of sufficient power to ensure signals of ample strength being received: therefore the whole transmitting plant must be built and arranged.on thoroughly sound lines.

12. In general it may be said that the essential factor of telegraphy depends on reliability and speed.

Reliability