RADIO NOTES

Rotorua Morning Post, Volume 1, Issue 119, 12 January 1932, Page 2

RADIO NOTES

"Kathode."

By

Conditions for radio reception in Rotorua have not been good for some - time past. Low powered sets have been almost out of the running, while powerful receivers have had; to' be opened out to such an extent the noise level has been raised above the average signal strength. The YA "stations have been suffering from fading, and static has been more or less present on most evenings. The New Plymouth station, 2YB? has been coming over with good strength and has been a good stand-by when "the higher powered transmitters have been weak. These conditions will remain about the sarne until after the equinox. The American station KFI has been received in Rotorua at good strength at '4 p.fn. in the afternoon. Several other Americans have been heard well and one local listener reports having logged fifteen of them in one evening on a four-valve receiver. These conditions are quite normal, and listeners after "bags" of stations from the U.S'.A. should he able to receive them now. 1 Conditions on short waves have been good during the past week. The 40-metre American stations have been coming in well from 5 p.m. on, though those on shorter waves have sufffered from sever fading. The Siberian station has maintained fair strength edch evening and Siam arrives at good speaker strength after 11 p.m. The local transmitters report good conditions and ZL1BG (Dr. Thompson) , made good contact with Spain during i the week. ZL1BN (Mr. D. W. Tapp) also succeeded in holding contact with Switzerland and Italy during the past ;few days. The publicity obtained \ from these world wide contacts cannot , be over-estimated and it would be a wise move if each of the transmitting stations in Rotorua were supplied with pamphlets to be enclosed with their contact cards. When a contact is made, each? transmitter eoncerned posts a card confirming the contact, and as these cards are sent to the four corners of the world, Rotorua would receive unique publicity. During the past year, one transmitter sent 153 cards to the United States alone. When an a.c. receiver using a pentode valve becomes noisy, the valve should be tested. Several cases of noisy sets have been traced to a defective pentode. In some cases the valve 'has been almost new, while on others the defect has occurred through long use. The past year did not produce any revolutionary changes in radio receivers, and so stands out in contrast from previous years. Step by step, as each year passed, we can trace the development of receivers from the homely. crystal set to the modern a.c. instrument, hut 1931 brought only changes in design and the addition of several refinements. 1931 produced the compact a.c. receiver using the superhejxodyne circuit and pentode valve- — both of which were developed some years ago. . For some time past it has been evident that the number of home built receivers has been on the decline. This, no doubt, is due to the fact that modern a.c. construction is beyond the average enthusiast. . But the experimenter himself has not disappeared, although he has decreased in numbers. Every now and again a new development arrives and he builds himself or his friends another set in advance of the manufacturer. While the tables may have been turned in receiver building, in this, that the manufactured set is generally better than the home built design, the home constructor has two advantages over the manfacturer, namely, the advantage of later developments in design and the advantage of overcoming location peculiarities. "Kathode" inspected two a.c. locally built receivers, over a year ago, which were almost a year in advance of the manufactured sets. The screen grid deteetor, now almost universally used, were employed by amateurs almost two years ahead of manufacturers. Not so long ago, people were asking "What is this radio music from the air everyone is talking about?" Today the same people are visiting talking picture theatres and taking them as a matter of course. Much water has flowed under the bridge since 1921, when the first radio transmitter to broadcast music went on the air, and many developments have been made, among which is the talking picture,, ' .