RADIO NOTES

Rotorua Morning Post, Volume 2, Issue 399, 7 December 1932, Page 6

RADIO NOTES

"Kathode.")

(By

The past week has not been a good one for reception. Fading, distortion, static and local interference have been more or less present each evening, and with weak signal strength listening has been anything but pleasant. 2YA is well received during daylight but soon after darkness falls, fading hecomes severe. 1YA is not strong during the day and^ suff-ers from intense fading and distortion at night. ^3YA cannot he received before 5 p.m. but is fairly steady and free from distortion at night, though the tonal qualities leave much to be desired. Evidently. this statioii has not yet been hi*ought into line with 1YA and 2YA. 4YA is usually weak at

night and not worth tuning in. The Australian stations cannot he relied upon and it is seldom that they are worth listening to before 10 or 11 p.m. Short wave listeners report excellent reception of the English stations during their tests with Wellington and Sydney. The story of the unveiling of a monument, reported in tha loeal news a few days ago, was actually instructions being given from London to Cairo previous to the ceremony, and not an account of the unveiling as reported. Listening to 2ME Sydney, both sides of the conversation could he heard, though the Cairo station could n6t he heard direct from Rotorua.

The present cricket test. England , v«r.-:us Australia was relayed from • 2ME, Sydney on short wavlp, and ! Mv kvu uu in Rotorua at good volume. ; The listener tuned in early and was ' . rj. ).ving cxcellent reception from 2 , p.m.' in th* af ernoon, long before the j nrdinary broadeast stations could he heard cven in paris of Australia. Now thnt summer conditions are vcii ostablisbed, it is necessary to see that the carth eontact is kept moist. Oaro should be t-aken to keep ■ he ;'vt covered when not in use, as the !ine *(lu.st oi summer penetrates the uelieatc- ports of a receiver, and the bigii pnvontage of su.lphur contained in' local dusi, soon corrodes most meial parts. Dust will also create mysterious noises in a set by setting bJtween the plates of variable condenser*. and penetrating shaft bearings. A certain amount of noise can. be cclerated when the apparatus causing 'it is esvemial, ■such as violet ray and X-ruy, but the interference being ex.erienced locally .from certain Neon light advertising signs should he remedied without delay. One particulurly bad plant, causes interference over a whole bloek and ruins reception ior at leasi seven license holders.

Complaint.- of morse code interfer•nce on th e broadeast band have been rnado on many occasions, and local aniateurs are usually blamed, but the writer has no hesitation in saying ihat most of the code heard has been vansumted from ships. On one oe■:*asion during the past week, a con- . inuer.s strer.ni of code interfered u jth ihe reception of 2YA for ovei* m hour m; J. at that time none of the lf*eai aniateurs were on the air. That -iitv rl* -.rence is sometimes received "ror.i transiniiters in Rotorua is ceraiu, but in most eases it is accident- \ j.jul easily remedied. Listeners ex-

mrioiicing morse interfcrenc * oi a tui nature should get in touch with v>r.e oi' ihe local transmitters, giving vime' heard and any other information .f a valuable nature, when steps will ' } .* taken to remedy the cause. N"o little stir has been caused in the radio world by the latest of Marconi'o achievements in transmittting on ultra short waves over a distanee of under 200 miles While it is yet too early to predict the use of such high frequeneies it is probable that they will not be used to the same extent as the wavelengths in use today. Amateur experimenters have ,eon using the high frequencies below 10 metres for some years and have i'ound that little or none of the energy is r -fiected by the Heviside iayer. That being so, unless reflectors are used at frequent intervals from he transmitter the radio frequency nergy will be lost in space after .•overiug a few miles. No information is diselosed giving details of methods used, but from what we already know •jf these extremely short waves, it is probable that Marconi usid a balloon aerial or a series of i-elay or reflector stations. If reflectors were used, the oxpense of transmitling over a thou--and miles would be great and if .a balloon aerial was used, the height necessary to transmit over a similar distanee would he cumbersome. If other methods liave been used, thcn a real and valuable discovery has been made. It is doubtful though whether the use of such frequencies will play any part in domestic life, though their use may extend the possibilities of short distanee television. Without doubt, inter plane communication will be carried out on wavelengths below 5 metres, and aviation will find ihe ultra high frequencies useful for all communication work. The trend in radio design seems to be a return to the 245 type of valva in prtference to the greatly boomed pentode. The torie from two 245's in push p.'ull is far superior to a couple of pentode and the pentode will only be used in eompaet reeeivers where room is the primary consideration.