WIRELESS NEWS FROM FAR AND NEAR

Auckland Star, Volume LVII, Issue 251, 22 October 1926, Page 14

WIRELESS NEWS FROM FAR AND NEAR

The Northern Boxing Association has granted permission for the broadcasting of details of next "Wednesday night's fights in the Town Hall. The propriety of transmitting ringside accounts of boxing contests has raised quite a flood of correspondence in Australia, most of it strongly in favour of the practice. Another crystal record comes to light. Using a small set that could be carried in an overcoat pocket, a ship's officer picked up IYA at a distance of 170 miles.

Auckland district has now well over 3000 licensed listeners, and the numbers are increasing steadily week by week. The most remarkable feature of the boom is that there are fully two hundred dealers in radio apparatus in the province. When it is considered that in the Sydney metropolitan area, with twice our provincial population, there are less than a-quarter of this number of dealers, it is plain that the majority who are now handling radio goods will retire from the business when the first eager rush to purchase has passed.

It is wonderful what a big difference a good aerial makes to a crystal receiver. • Many people have said: "I don't want to bother much about an aerial, I have have only got a crystal set." In a crystal set where no amplification is used the aerial system is the most important factor in good reception. A southern paper is responsible for the statement that there are 20,000 receiving sets in the Dominion at present, only about 6500 of which are licensed.

There is a most persistent rumour in local wireless circles that "Uncle George," that genius of the microphone, who presides at 2BL, is coming to the Auckland station. Inquiries fail to find any foundation for the run»our.

2FC is now 'broadcasting for fourteen hours daily. A lengthy letter has been received from "Cadmium" on the question of tihe hydrometer test for batteries as recommended in this column. The matter is too involved and technical for newepapcr discussion, but reference to the instructions supplied by the manufacturers of storage batteries will confirm the merits of the use of the hydrometer. Letters of appreciation from wireless fans in all parts of Nei* Zealand iiave been, received by the organist of the Pitt Street Methodist Church, Mr. T. S. Webster. On Thursday evenings music is relayed from the church to station IYA, whence it is broadcasted. One letter expressing appreciation of the music was posted at Tumbybay, Eyrie Peninsula, a little-known township in Australia, something like 2800 miles away. Requests for favourite compositions have come from almost every town in New Zealand. Incidentally many'of the letters give further proof of the joy that the radio broadcast has brought into the lives of the old and the sick.

REGULATION RE AERIALS. A wise precaution*by the Government has been taken by the gazetting of the following; regulation: Wireless aeria,ls shall not, without the consent of the licensee fpr the supply of .electricity concerned,; be erected above 'or below wires used for the supply of electricity, or sufficiently near to such wires to permit of contact! with them should either class of wire break, become detached from its support, or the support fall. Wireless aerials shall not, without the consent of the Minister, be-erected above or below any electric line erected and maintained by the Post and Telegraph Department. . ■ • p

ANALYSIS OF DETECTION. The method of detection in valve work commonly used makes use of a grid leak and condenser. The operatrpn of- the circuit may be roughly as. follows: In the absence .of incoming waves the potential of the grid is tae, same as that of the filament. .^lncoming-,waves cause the grid to become alternately.more positive and more negative than the filament. While the grid is more negative, nothing happens, but while it vie more positive it attracts negative electrons. These electrons cannot get off the grid once they are on it (the grid is not hot like the filament), except via the high resistance, -which is called the grid leak. If, for the moment, we suppose there is no grid leak, provided, we can see that after a'very few waves have come in the elec.trons drawn to the grid will charge it to a steady, megative potential equal to the maximum instantaneous potential of the top of the coil in the antenna circuit. This steady negative potential causes a reduction in the plate current. Even if the waves cease coming :in or their amplitude is diminished the grid retains its negative charge, since there is no way •for the electrons to get off it. So We put in a very high-resistance path, by which they may slowly (compared to the wave frequency) escape so that, if the, amplitude of the incoming waves slowly (i.e., at voice frequency) diminishes, electrons will leak off until the grid potential drop to the new maximum; value of potential at ihe upper end of the coil. In this system the greater .the strength of incoming waves the less the plate current. The size of the grid leak is more or less important. If its resistance is too great it is possible that the grid of the valve will block on strong signals, whereas if the grid leak resistance is too' low,

By "PHONOS. ,,

LOCAL SHORTCOMINGS.

the signal strength will be decreased. For the ordinary 201-A type of valve a grid leak of about four megohms resistance j will give the best results. If a soft; detector valve is used a somewhat lower: resistance leak is generally required,, about one-half, to two megohms being about right.

MORE FREAKS. In England recently a mosquito was induced to broadcast its song. Heaven knows -why anyone should 'have wanted to engage a mosquito as a soloist; too many sleepless nights are associated vvith the insect. But, anyway, the experiment was tried, and so Cynthia; the only contralto mosquito doing the "big time." in London, was engaged. She arrived at the studio on time, and was given a little respite to recover her breath; she was asked to sit on the microphone. It was then the tragedy happened. Whether the metal gave her cold feet, or whether she had cold feet when she came to do her trying stunt will now never be known. Cynthia died at the very moment of switching ondied mute, uncomplaining, ready to do -her duty, though snatched by-, death in the very moment of its accomplishment. This is a true tale. Her pho£ograpli is in the "Radio Times" —a death mask —because there is an absence of that ready good nature one is accustomed to associate with the live insect.

The general dissatisfaction that as being felt at the quality of the programmes from IYA is typified by the letters that appeared in last night's "Star." It is evident that there will be a decided decline both in the popularity of listening-in and in the radio trade unless some very radical improvement is effected very quickly. Wednesday's programme, as an example, was both mediocre and tedious. To have a surfeit of band music such as was then sent out is no tribute to the Broadcasting Company's judgment in supplying an entertainment, and a repetition* of such fare will not only discourage further prospective licensees, but may cause many to abandon in disgust what they had hoped would be a source of pleasurable and varied entertainment. It is quite time that the facts were faced. The number of listeners in the Auckland postal district is mounting Tip towards the 4000 mark, and if they are properly catered for" they should exceed 5000 in the province ere the year closes. The Broadcasting Company's revenue from the Auckland district alone must be at the rate of about £5000 a year already. In fact, it would appear that at present the north is carrying a very big proportion of , the radio expenditure throughout the Dominion, and the station catering for us is being managed in detail .-from Christchurch. Certainly the tail is wagging the dog, and there will be a very general outcry unless the system is altered. Before the Dominion scheme ' was finalised there were suggestions—tftfvourably considered too— for local advisory boards for each station. If such bodies are not possible, then more scope should be given for running IYA so that it will reflect Auckland, in programmes; and in details of, control. ; ' ■'„ "

DONT'S. Don't permit your telephone receivers to be jarred. Such treatment demagnetises the permanent magnets or develops loose connections. Have a hook to hang receivers on. Don't permit batteries to lie idle. If a battery is to be out of use for several months, leave it in care of a service station. Don't permit dust to gather in your radio set, for dust causes electrical leakage. Don't use a gas pipe for the lightning ground. . : Don't ■ stretch aerial across power ■or telephone wires. This is dangerous and unlawful. "Don't burn valves too bright. If you do your reception will be poor and your valves will not last long. Don't forget to shut off your set. Don't have a long ground wire. Don't use cheap insulators for your aerial. They are unsafe. Don't annoy your neighbours if you have a regenerative set — keep below oscillating point and enjoy better quality reception. . . Don't stand a "B" battery on its side instead of top up. If you do the electrolyte will ooze out and make contact with the cells, causing a short circuit. - Don't lay your set down with a jar or permit the cover of the set to. slam. Fine adjustments in the set or in the valves might be disturbed so as to impair the quality of your reception. STATISTICS OF INTEREST. An American radio engineer has been delving into official figures concerning radio in his own country, and has deduced the fact that slightly. more ' than half of the sets in use there are of the home-made variety, and that nearly halt 6f these are of the regenerative type. The most popular set is the five valve, which claims a 31 per cent proportion of those in use. There are seven per cent, of eight valve sets, and half per cent' with ten valves. Fully threequarters of the army of listeners in the States use outdoor aerials.