A DX-PEDITION from 1928




(By “Experimenter.”)

From the Press, Volume LXIV, Issue 19338, 16 June 1928, Page 10.

Although a very pleasant evening may be spent listening to New Zealand and Australian broadcast, this form of radio entertainment is poor sport when compared with the fun to be had in searching the air in the hope of “logging” stations on the other side of the world, or, to put it in radio parlance, hunting for “DX” —the radio symbol for distance.

With the discovery and subsequent rapid development of short wave radio, reception of stations in distant parts of the world has already become an accomplished fact, and to-day the band of “DX” listeners numbers hundreds of thousands. The spirit of competition among listeners is very keen, and in Now Zealand there are many who think nothing of keeping a night-long vigil on the chance of bringing in a new station.

During last week-end three Christchurch radio men —Messrs R. A. McLennan, J. Orbell, and the writer—kept a practically continuous radio watch from Friday evening until noon on Sunday, the object of which was principally to obtain data on European phone stations which transmit in the early hours of the morning, New Zealand time. Three receivers were in commission, these being a Bremer Tully counter-phase eight, an eight tubo superheterodyne, and a specially constructed short wave outfit. The station was located high up on Cashmere Hills, and a special aerial was erected for the occasion, this, for the most part, being used in conjunction with the short wave receiver.

A start was made at 8.30 on Friday evening, when the signals transmitted from the Southern Cross, on flight from Suva to Brisbane, were held continuously until 3 a.m. on Saturday. The strength was exceptionally good, and the Morse could be heard over 100 ft from the loud speaker. While the aeroplane was passing through the heavy storm between 8.30 and 11.30 o’clock, the note of the generator often changed violently in pitch, indicating that the plane was passing through bad weather, alternately climbing and racing. Prior to closing down, the French station at Saigon, Indo-China, was heard on phone, all announcements being made in French.

Concert from England. At 7.30 on Saturday morning the aerial switch was thrown over again, and this time 5SW, Chelmsford, England, came in with a rush, broadcasting gramophone records on a special Australian test transmission. This station went off the air at 8.15, New Zealand time, and KHAB, the Southern Cross Station, came through at signal strength equal to that of the previous evening. The aeroplane was held until the landing was made at Brisbane. The transmission on short waves was much more clear than the rebroadcast by 2YA, Wellington.

After several alterations of a minor nature had been made, the short wave set came on the air again at 1.15 p.m., when a number of orchestral selections, played by “The Columbians” in the studio of WGY, New York, and broadcasted by 2XAD, one of WGY’s short wave stations, were heard at good loud speaker strength, maximum volume being attained at 3.5 o’clock. The announcer, who was typically American, hoped that the transmission was being picked up in Australia The other WGY station, 2XAF, was also heard, but its transmission was not nearly so steady as was that of 2XAD.

The short wave outfit was given a spell until 1 a.m. on Sunday morning, when IDO, Rome, was heard having a little chat with a station in South America. Within a few minutes of this reception PKX, Malabar, Java, was. tuned in on 27 metres, on both Morse and speech. This was followed by a German station, but the call sign was missed. The station was working Japan, the medium of conversation being the international code of abbreviations. Farmer’s short wave station at Sydney was heard next, apparently testing with Great Britain. At 3 30 PC JJ, Eindhoven, Holland, opened up, and, although rather weak, the speech and music were very clear. Other calls received during the night were:— GLW, Dorchester Beam Station, England; VNB, South Africa; PCG, Malabar. Java; GBL, Leafield, England; AGK, Nauen, Germany; JES and JEW, Osaka, Japan: NAA. Washington, United States; FW, Ste. Assisse. France; SPW, Rio de Janiero; VIS Sydney: 2NM (G. Mareuse), Caterham England: NPG, San Francisco; LPI Buenos Ayres, South America: and NPM. Honolulu. Apart from the calls listened above, over 20 amateur transmitters were logged, the “stations being located in England, France, Germany, Russia, America, and Australia.

The Best Yet.

As mentioned already, the short wave set is of special construction, and, incidentally, is the best that the writer has yet seen in operation. It has four valves, there being one stage of radio frequency amplification, detector, and two stages of audio frequency, and the set is entirely encased in aluminium. The radio frequency tube is one of the new screen-grid type, and has a very high amplification factor; in fact, it is considered to be worth at least three ordinary stages of radio frequency amplification. Each unit is completely shielded, and, in consequence, capacity effects are reduced to a minimum; this also makes for stability of operation. The set is very easy to control, and, at the same time, the degree of efficiency is exceptionally high, the receiver combining sensitivity with selectivity.

Shortly after four o’clock on Saturday the Bremer Tully was brought into operation. 2FC and 2BL, Sydney, and all the New Zealand stations being heard. The set was very sensitive, and gave faithful reproduction, and the selectivity was all that could be desired in any eight-valve set. All the New Zealand and Australian A class stations were listened to in the early part of the evening, and at 10.30 4QG, Brisbane, was tuned in for the reception of the Pacific flyers, which was broadcasted on relay by that station. It was possible at all times to follow the speeches in spite of very pronounced fading, this being overcome by utilising the rejector circuit. When the station was tuned in at maximum volume, the use of the two trimmers enabled the operator to “clip” either side band at will. If this had not been possible a large portion of the speech would have been lost. By use of the rejector it was easy to cut out 3YA and bring in 1YA, and without the slightest “mush” from the Christchurch station. When the set was properly balanced, the trimmer of the rejector stage was the only adjustment needed for medium strength signals.

Japanese Entertainers.

During the evening all the Australian A class stations were heard at loud strength, particularly 2FC, 2BL, and 3LO. The Adelaide and Brisbane stations were much weaker than usual, although, strange to relate, 2KY, Sydney, usually a very weak station, and 3DB, Melbourne, came through at exceptional strength. A few minutes after midnight concert items were heard from stations JOAK and JOBK, Japan At this stage static was very bad, otherwise the “Japs” would have given the loud speaker a bad shaking.

At 7 o’clock on Sunday morning the French station at Saigon was picked up again, PCJJ, Holland, having closed down at 6.30, after a splendid concert programme. Another couple of hours were spent in searching the ether, but no other phone stations were brought to light, and it was decided to call it a day—or rather a week-end and three very tired men packed up their gear and returned to town for a much-needed sleep.

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