Short-wave Jottings

Radio Record, Volume II, Issue 44, 17 May 1929, Page 32

Short-wave Jottings

v dl Mr. Sellens writes :- LETTER and card have just been received from Messrs. James Richardson and Sons, . Ltd. Winnipeg, Canada, owners of radio stations CJRM, Moose Jaw, Sask. CJRW, Fleming, Sask, and CJRX, Winnipeg, Man., in reply to a report sent,on reception of the latter station. CJRX operates on 25.6 metres . with the power of 2000 watts. They state yea at programmes are "tied in" with The schedule of this station, reduced to New Zealand time, is as follows :- Daily except Monday, 10 a.m. till 12.30 p.m, 3 Monday, 4 a.m. till 7.30 a.m.; Tuesday, 2.30 p.m. till 3.30 p.m.; Wednesday, 1.30 p.m. till 4 p.m.; Friday, 1.30 p.m. till 3 p.m. Central standard time is observed at Winnipeg. The owners of CJRX state that they would appreciate further reports as they would like to know if their station is reaching this district consistently. The "Wireless World" report having had a message from 7LO Nairobi, Kenya, to the effect that their daily transmissions are now made on 81 and 400 metres. Lot This station has not been heard recently by the writer, cither on the above or their previous wave. They do not appear to appreciate reports from distant countries, as a Christchureh friend and myself have sent detailed reports with copies of the "Radio Record," which, after some months, remain unanswered. ° The following hints should be of assistance to the inexperienced short-wave listener :- Hints on Short-wave Tuning. N the short waves it is often essential to allow the set to oscillate mildly whilst searching in order to pick up the carrier wave, since a station may easily be passed over if this is not done. But do not, once you have found a speech carrier, go squeaking up and down all over the place and cause interference with others who are listening to the transmission. As soon as you have’ found the carrier loosen your reaction a little, and then slightly re-adjust the grid tuning condenser. In this way you will be able to tune in the transmission very quickly, and will cause a minimum amount of -: -=-vvervweeNG YL eeeeesese ere NN

interference to other people. A transmission which can be heard only by keeping the set in oscillation and tuning to the silent point is practically never worth hearing at all. The proper adjustment for hearing telephony, and the one which gives far the best quality and the sreatest signal strength, is that which vrings the set to a condition just below the point of oscillation. This desirable state of affairs can take place only where reaction is perfectly smooth. Should your short-waver show any tendency to flopping into oscillation you will never have any success worth talking about upon the wavelets. When these symptoms are present there are three points worth remembering. Grid-leak Vaiues. IRST of all try a higher value of gridleak than you are using. If this does not make things right disconnect the grid leak from "A" X and wire it instead te the slider of a potentiometer wired across the "A" busbars. In many cases smooth reaction control will be secured when the slider is somewhere about the middle of its travel. Supposing that neither of these remedies is effective, the high-fre-quency choke is the next component to be attended to. One that suits most circuits of the Reinartz type can be made by winding from 60 to 80 turns of fine enamelled wire in a single layer on a piece of ebonite or paxolin tube 1 inch in diameter. There is one other point that is worth noticing. Sometimes even if the circuits and components of the rectifying valve are up ot the mark reaction is unsatisfactory because the low-fre-quency transformer that follows the valve is of an unsuitable type. A tip that sometimes works wonders in such a case is to fix a variable grid leak across the secondary of this transformer. Saturday, May 4. SW was R8 from the commencement at 5.380 a.m., readability was very poor, This was much better by 6.30 a.m. PCJ was 100 per cent. readable all through from 5.30 a.m. till 7.80 a.m. at about RS-9. At 6.12 they called Mr. Gledhill, of Christchurch, and hoped that he was receiving their signals well. They were again tuned in at 1 p.m. when strength was R2, increasing R8 by 3.30 p.m. ~

At 5 p.m, a special transmission for the Sydney Radio Mxhibition commenced. Greetings were sent to the Mayor of Sydney, and others, ‘he station went otf the air just after the commencement of the special programme for about tive minutes. Signals were very unsteady, aiter.the temporary stoppage. 2XAD was R6 when tirsh heard at 1 p.m. The usual "General Electric" programme, "Half-hours with the Senate," ete., were well received. KDKA. were heard at good volume, but not so clear as they should be. The "Slumber Hour" was_ broadcast from 2.30 p.m.-3.80 p.m., followed by a clock striking 12. Weather forecast and baseball scores completed the programme, signing off at 3.35 p.m. , At 2 p.m. a station on PCL’s wavelength, 18.4, was heard at R3, increasing quite a great deal by 2.30 p.m. Several musical items were given, but no call was heard, W2XG on about 82 metres at 6.35 p.m. called, "Hullo, London, ealling you." Then the usual "write down "" followed. Sunday, May 5. At noon 2XAD was R83, increasing rapidly in strength. From 2.80 p.m. the programme was dedicated to the Byrd Expedition in "Little America." It was stated that a specially constructed an- tenna-the Byrd antenma, was being used. This was a directional aerial pointing due south from the transmitting station. The first item was appropriate to the occasion, being named "Sway Down South." KDKA was good strength, but not so clear as 2XAD or 2XAF. The latter station was transmitting simultaneously with 2XAD. Monday, May 6. On about 31.2 metres at 6.20 am. a foreigner was talking at R4+, The time signal was heard at 6.30 from the Melbourne Observatory, via 3LO, followed by the regular musical, programme Strength R9, with uneven fading. VK2MBE, Sydney and VPD, Suva, car ried out a long duplex telephony test ‘til] 9.10 p.m. Both were received at R9. Wednesday, May 8. At 5.50 pm. W6XN (KGO), were giving news items till 6 p.m. From

then till 7.80 p.m. the programme was by the "Trocaderians,"’ from the San HFrancisco studio of the National Broadcasting Co. Reception was excellent at RY. Friday, May 10. T 5.80 am. the Big Ben from 5SW was R&S. The title of the following talk was missed, but it was about "Operas." It was 100 per cent. readable, Two Columbia records were heard next, followed by a talk on "China." At 6.15 a.m. the musical programme opened at — the studio with an orchestra item .by Coleridge-Taylor, followed by 10 solos. Volume was still better now, ui ce good in all respects. On about "fo.t metres, a foreigner was talking at about R38. A litle lower-about 15 metres-a man and. woman were talking, duplex telephony, I think, Strength Rs,