NEW ZEALAND GAZETTE

28 NOVEMBER

5921

clearly and distinctly marked, and a positive indication that 2182 kHz has been correctly selected shall be given:

(f) It shall be possible by means of a single control to change from any type of emission to any other type for which the transmitter has been designed to operate, except that on 2182 kHz selection of the A3H mode shall be automatic. The positions on the switch shall be clearly and distinctly marked.

(g) A control to switch the equipment on and off (with the exception of heating circuits as provided for in subclause (9) of this clause) shall be provided. This control may have a standby position.

(h) A special control for the disconnection of heating circuits from the power supply as provided for in subclause (9) of this clause may be provided.

(i) If additional controls are provided, they shall be for use only for transmission in frequency bands additional to that required in subclause (1) of this clause or for operation of the alarm signal generator specified in Part II (A) of this Schedule or for both purposes.

(7) Receiver Controls—

(a) Selection of the frequency of 2182 kHz shall be by not more than 2 controls. For frequencies other than 2182 kHz, more than 2 controls may be used only in the case of selection of the frequencies by means of an unprogrammed synthesiser or similar device.

(b) The control or controls which select 2182 kHz shall be clearly and distinctly marked, and a positive indication that 2182 kHz has been correctly selected shall be given.

(c) It shall be possible, by means of a single control, to change from reception of any type of emission to any other type for which the equipment has been designed to operate, except that on 2182 kHz selection of the A3/A3H mode shall be automatic. The positions on the switch shall be clearly and distinctly marked.

(d) The receiver shall be fitted with a clarifier (a fine-tuning control) to adjust slightly the nominal tune frequency of the receiver. The tuning range of the clarifier shall be within 250 ± 50 Hz above and below the setting determined in clause 7 (11) of this Schedule. The rate of adjustment of the clarifier control shall not exceed 3 Hz per degree of rotation. The frequency of the transmitter shall not be affected by operation of the receiver clarifier control, and when the receiver is switched to A3H reception the clarifier shall be disconnected.

(e) If an externally adjustable aerial tuning control is provided, the receiver shall meet the requirements of this Schedule on any frequency in the Maritime Mobile Bands between 1605 and 6525 kHz, irrespective of the setting of this control.

(f) If a device is fitted to reduce the effect of impulsive noise it shall be fitted with an on-off switch.

(g) A manual audio gain control shall be provided.

(h) A standby control to switch the receiver on and off, with a standby if desired shall be provided.

(8) Size of Controls—All controls shall be of such size as to permit normal adjustments to be performed by a person wearing thick gloves.

(9) Warming-up Period—

(a) The equipment shall be operational 1 minute after switching on. It shall meet the requirements of this Schedule after 5 minutes, except as provided in paragraph (b) of this subclause.

(b) If the equipment includes parts which require to be heated for longer than 5 minutes in order to operate correctly, for example crystal ovens, then those parts can be allowed a warming-up period of up to 30 minutes from the instant of application of power to them. After this, the rest of the equipment shall be switched on and the requirements of this Schedule shall be met.

(c) Where paragraph (b) of this subclause is applicable, the power supplies to the heating circuits shall be arranged so that they remain operative when other supplies to the equipment or within the equipment are switched off. If, however, it shall be possible, for maintenance or emergency purposes, to readily disconnect such circuits from the power supply by an approved method. If a special switch for these circuits is provided on the equipment, the function of this switch shall be clearly indicated, and the operating instructions shall state that the circuits should normally be left connected to the supply voltage; a visual indication that power is connected to such circuits shall be available on the front panel; if necessary, an indicator shall be provided specially for this.

(10) Frequency Adjustment—

(a) It shall be possible to change the transmitter from operation on any frequency to operation, within the terms of this Schedule, on any other frequency specified in subclause (1) of this clause in a period not exceeding 20 seconds.

(b) It shall be possible to change the receiver from operation on any frequency to operation, within the terms of this Schedule, on any other frequency specified in subclause (1) of this clause and reduce the frequency error in the A3J and A3A modes to less than 30 Hz in not more than 30 seconds, except that it shall be possible to set the receiver to 2182 kHz in not more than 10 seconds.

(11) Transmitter Meters—

(a) The transmitter shall incorporate an indicator of aerial current. Failure of this indicator shall not disconnect the aerial.

(b) Other indicators or meters shall be included, as necessary, to enable the transmitter to be checked and adjusted.

(12) Alarm Signal Generating Device—The transmitter shall provide facilities for readily using, by approved means, the radiotelephone alarm signal generating device. The performance requirements for this device are listed in Part II (A) of this Schedule.

(13) Automatic Delay—If it is necessary to delay the application of power to any part of the transmitter after switching on, the delay shall be provided automatically.

(14) Facilities for Two-Way Communication—

(a) For simplex operation, the equipment shall be capable of being changed rapidly from ‘transmit’ to ‘receive’ and vice versa.

(b) A non-locking switch shall be provided for transmit-receive switching, which, in its normal position, leaves the equipment in the receive condition with the loudspeaker or the headphones or both in circuit. When the equipment is in the transmit condition, the microphone shall be in circuit, and the loudspeaker shall be disconnected automatically.

(c) If a voice operated device is provided, it shall meet the following requirements:

(i) The operate level of the device shall normally be 25dB below the level which produces maximum modulation of the transmitter, and means shall be provided for the adjustment of threshold of operation between 6dB and 25dB below the level which produces maximum modulation of the transmitter.

(ii) The operate and release times of the device shall be within the limits given in the following table. For the purpose of this test, the operate level shall be defined as