EXPERTS SAY

Sun (Auckland), Volume III, Issue 729, 31 July 1929, Page 16

EXPERTS SAY

A defective HIT. battery sometimes gives rise to distortion that is only noticeable on certain notes.

It is unwise to use indifferent quality condensers for inter-valve coupling. For if there is a slight fault in this component distortion will inevitably result.

Do not throw' away old hacksaw blades, as one of these, filed down and put on a handle of suitable size, will make a good keyhole saw for cutting small holes in ebonite. «* * * It is advisable to test the voltage of any dry battery at regular intervals, because if any of the cells become defective all kinds of mysterious troubles can arise in the set. High-tension accumulators should never be allowed to run down below 1.8 or 1.9 volts a cell, and they should always be recharged promptly and not left standing idle. * * * Voltmeter tests of H.T. voltage should be taken after the battery has been in use for a little time, as the correct working voltage is not shown when the battery is standing idle. * * * Although no current is actually taken from the grid-bias battery, its paste electrolyte tends to dry up after six months or so, so that the battery should be replaced when the distortion appears or its voltage drops.

When adjusting a neutralising condenser it is a good plan to choose hours during which there is no broadcasting, or else to disconnect the aerial so that there is no danger of interfering with your neighbours while the adjustments are carried out. * * * The holes in a panel through which the fixing screws are driven to secure the baseboard to the panel are best drilled when the panel and baseboard have been placed in their correct relative positions. If fixed together outside the cabinet they may not make a smooth fit such as would otherwise be the case. HUGE NEON SIGN Mrs. Lois L. Emerson, wife of the Governor of the State of Illinois, touched a button in the executive mansion at Springfield, 111., which turned on the current to -what is claimed to be the largest Neon sign in the world—the “Majestic Radio” sign on the Harry Alter Building in Chicago, 111. For the first time in history a complete radio and telephone hook-up was used to complete the circuit. Three Chicago radio stations, WMAQ, j WBBM, and KYW, announced the time promptly at 5.30 p.m., and advised that all was in readiness for Mrs. Emerson to touch the button. At the executive mansion in Springfield, Mrs. Emerson’s little grand-daughter, two-year-old Miss Watkins, had just tuned in the “Majestic” receiver, and as the announcement came over the air, Mrs. Emerson pressed the button and the giant sign flashed on. The American Telephone and Telegraph Company made most extraordinary arrangements so that “Majestic” might thus be honoured by the Governor’s wife. Over 16 miles of special wire was laid, and the services of 64 men were required to complete the hook-up. The “Majestic” sign is over five stories in height, and the lettei “M” alone measures 32ft. Thousands of feet of Neon tubing make th'3 sign visible on any night, and during clear weather it can be read when 40 miles out on the lake. Newspapers credit “Majestic” with "an outstanding landmark on the Chicago sky-line.”