THE LISTENERS' GUIDE

Radio Record, Volume I, Issue 49, 22 June 1928, Page 15

THE LISTENERS' GUIDE

SPECIAL INTEREST TO CONSTRUCTORS | (CONSTRUCTORS and experimenters will find the "Listeners’ Guide" exiremely handy for general reference for lists of New Zealand, Australian, American and Canadian stations, with power and waye-lengths, short-wave stations, and a wide range of other information. Of special interest to constructors there is a list of practically all valves ea

on the New Zealand market, showin at a glance their main characteristics and the positions in the set for which each valve is best suited. There ig also a table giving the necessary gridbias for any valve likely to be used in audio stages, ANOTHER useful list is that of rec tifying valves that are sold without the stipulation that the purchaser must be in possession of the charger for which they are designed. Valves for B battery eliminators and A battery charging are also included, full particulars of all the rectifiers being given. OTHER tables include winding of solenoids for given wave-length; turns for spider-web coils to tune with condensers of different capacities; turns for secondary coils tuned with condensers of various capacities; tables for making fixed mica condensers of capacities from 56 mfd. down to .00015; wire tables; list of amateur transmitters, ete. (HONSTRUCTIVE articles include erystal receivers, with the "R.R." Selective Crystal Receiver, which so ‘many constructors have found highly suecessful, and which makes a highly ‘effective wave-trap. Then there are ‘two amplifiers for the crystal, a one: and a two-valye. The ever-popular four-valve Brow ing-Drake is fully dealt with, including the amplifying for which inquiries ‘are coming to hand in connection with ‘the two ILE. tuning unit. The "Record" short-wave receiver is fully de‘seribed, both as a complete shielded three-valve receiver, and asa one-valye "converter" or "adapter," which can be ‘plugged into the detector socket of ‘any broadcast receiver and thus use the audio amplifier to increase the yole ume of the short-wave reception. Other information includes the Government: regulations relating to wireless listeners, a handy glossary of radi terms, ete. The "Guide" can be obtained from your dealer for 2s. 6d., or 2s. 9d. post ed from the "Record" office.