Breaking into the Amateur Game

Radio Record, Volume IV, Issue 27, 16 January 1931, Page 7

Breaking into the Amateur Game

Part I[V-On the Air for the First Time

By

Q.R.

L.

=~ | if) tuning of the Hartley trans@)i mitter described in the last article is not a difficult process. If the transmitter has been solidly constructed so that no vibration of parts or leads is possible, and a suitable power input is used, the outfit is capable of producing a clean, steady signal of which the operator will be proud. The tuning, ~however, will help to determine the character of the signal, and may completely change its note, if an RAC input is used. .Hence it is important that the-transmitter .be correctly tuned, fora poor signal re-. flects discredit on the amateur responsible. The-finer points*of tuning will come with actual experience on the air, but it is the essentials given here which count most. Now, before any attempt can be made to tune the transmitter, some means of listening to the signal must be avail- . able. For this the: ordinary short- ; wave receiver may be-used, or a monitor, which is simply a single valve receiver. The first essential is to tune the transmitter to the desired frequency, which must be within an amateur band-in the first case the 7585 metre band. While this is being done the antenna gear may be left disconnected. The receiver should be moved not less than six feet away from the transmitter and tuned (oscillating) to some wavelength known to be within the 75-85 metre band. AJl connections to the transmitter should be checked, the filament clip being on the fourth turn from the grid end of the plate coil. The power may then be connected up and switched on, the key pressed, and the oscillator condenser turned until a loud whistle is heard in the receiver.’ This is the transmitter’s wave, and a capacity of about .00025 mfd. in: the condenser should bring it within the wend.

if? no whistle is heard, the Fansmitter is not oscillating and the filament clip should be moved a turn or two closer to the plate end of the coil. When the wave has been located well within the band, the antenna gear may be connected up with the coil. separation about two inches, and the torch bulb in the circuit. With the key pressed, the antenna condenser should be varied until the bulb lights up to the maximum, and responds instantly to taps of the key. If more capa-. _ city is required across the ancoil, a small fixed conden)ser of about .00025 mfd. may be connected in parallel with the variable one. Although greater power is transferred to the antenna when its coil is closely coupled t@ the oscillator, a spac

ing of less than two inches should be avoided, because the wave radiated will be much broader (i.e., will cover more of the dial in a receiver and cause interference). The note will also be rougher, and the steadiness of the signal will be affected. It is important to remember that the strength of a signal is far

from being the only thing that counts. Stability and pureness in a weaker signal will often get through where a loud but "wobbly" one would be "lost in the depths.’ When the oscillator has been adjusted to a wavelength: within the band and the antenna tuned to resonance, the bulb must be shorted out: by closing the small switch, and the transmitter is ready to go on the air officially. Hven if the transmitter delivers a good signal, its effect will be lost by poor operating of the station. No amateur in these enlightened times enjoys working a station whose operator is ignorant of the cardinal principles of two-way contact. Two-way Telegraphy. ‘E shall begin right from the start and trace the procedure of making and maintaining a contact. Owing to the obvious necessity of brevity with Morse transmission, a system of abbreviations is in use throughout the world by all Morse stations. These are known as "Q" signals, and the more important

ones with their meaning are shown. The amateur has ‘also devised a handy standard system of abbreviations consisting mainly of shortened words, and a few of them are given, though they are-very easy to pick up. The snappy use of all the abbreviations adds much to the pleasure of a contact. Suppose the amateur has gone

through all the procedure necessary for establishing a station, and is ready for his first exhilarating plunge into amateur transmitting. Naturally he will be excited and very keen to make his first contact, no matter with what station. After making sure that the wavelength of his transmitter is cor‘rect, he should proceed to send out a call inviting any station who desires a QSO to answer him. This is known as a "CQ" call. If his call-sign were ZL2AA, he would send as follows: "CQ CQ CQ de (meaning from) ZL-2AA," and would repeat this for two or three minutes. At the end he would send AR, indicating that the call was finished. ; He would then switch the transmitter off and the receiver on, to cover the band listening for stations calling him. Such a call would take the following form, supposing a calling station were ZL-4AA: "ZL-2AA ZL---2AA ZL2AA de ZL-4AA ZL-4AA," repeated for two or three minutes and finished off with AR. ZL-2AA would then go back at 4AA, sending something like

this: "ZL-4AA ZI-4AA de ZI--2AA; R ge OM se QSO; tnx call; ur DC sigs QSA5 R8 stedi; QRK? ARK." Translated, this means: "Received O.K,, Good evening, old man, I am pleased to QSO. Thanks for the call. Your DO. note signals are easily readable, strength 8 What strength cre my signals?’ The tables for readability. and strength are shown. It is important to note that although signals may be strength R7, they may only be QSA3, owing to QRN (static) or QRM. (interference). Fullstops and’ semicolons in the message are translated by the symbol -. -, as shown in the diagram. The "K" the end of the message tells ZL-4AA to go ahead with his transmission, and he would then give the other a report on his signals. The two would continue thus to send anything of interest across to each other-"swap dope" is the amateur term. When one has exhausted his supply of dope he. would say: "Well OM QRU hr nw. so WL QRT. 738 es tnx QSO gn AR VA." This means "Well, old man, nothing further here now, so I will close down. Best wishes and thanks for the QSO, Good night." VA means that the QSO is finished. For the majority of QSO’s this sign-off is quite sufficient and is better practice than the usual rigmarole about nothing in particular adopted by some amateurs. If the signals are weak and hard to read, each word of the message would be sent twice, but the receiving operator will generally say if he wants it sent "double." Occasionally, if there is QRM on the particular wavelength of a station, the receiving "op." will ask the other to QSY, ie, change. his wavelength. This change should always be slight, just to get clear of the QRM, and the sending "op." should say whether he intends to QSY up or down in wavelength.

It will be found easier to pick up the simple methods of operat ing by listening .to amateurs actually "working" one another. The "Break-in" System. ANOTHER system of communication is "break-in." If handled properly it is more ine teresting and faster than the other system. It is simply "duplex telegraphy," each opera~tor having his receiver and transmitter on, and being able to transmit by merely pressing the key. Thus a conversation may be carried on without the necessity for "changing over." The sys tem is not used much in New Zealand, probably owing to the fact that interference from the transmitier is caused if the ne-

INTERNATIONAL PREFIXES

ZL-New Zealand VK-Australia VE-Canada . CT-Portugal D-Germany EAR-Spain El-TIrish F.S. F-France G-Great Britain

I-Italy T-Japan K-W.S.: Possessions LA-Norway LU-Argentine ON-Belgium 0Z-Denmprk PA-Netherlands PY-Brazil

RA-Russia SM-Sweden SP-Poland SU-Esgypt X-Mexico AC-China ZS-South Africa

THE INTERNATIGNAL MORSE CODE

0 6

0 F 7

1 Eengral Call _ 43# Atention Call End of Message End of Transmission

1 37

1 Comma

"Go Ahead "transmitting 9es Peceived Interrogation non 303 3 Period 6) Double Dash Distress Signal Lesodu

eeiver is nearby. Separate aerials are also necessary, but these difficulties could be easily overcome. Often two amateurs who have special experimental or personal traffic (messages) to put over, will arrange to work each other at fixed times. They establish what is known as a schedule, or "sked," and in America, where mes-

sage handling is unrestricted, thousands of skeds are maintained all over the country. . The amateur is always the leader in radio exploration. After discovering the capabilities of the present-day shortwaves, he is now experimenting on the ultra-short wavelengths of 10 and 5 metres. Test transmissions on these frequencies are regularly taking place, and although little encouragement. has been obtained from the results so far, those responsible are persevering. The Amateur Wavebands. if )F the amateur wavebands, there are | three chiefly used, each having definite characteristics. Thc 80-metre band is not good for DX, but is less subject to variations in reception conditions, and is used for most contacts within New Zealand. Beginners must stay on this band for the first few months, and all the year round they and many older hams can be heard’ chatting to each other on Morse and phone. On 40 metres the DX is moderate most of the year, and good between the months of December to March, when contacts with Europe are (easily made with only medium power. 'The disadvantage of this band is the

QRM caused by hundreds of stations being squeezed into a narrow channel only 300 k.c. wide. It is rare to conclude a DX QSO on "40" without experiencing QRM, more or less severe, from some station or other. The best DX band is the 20-metre band, but‘ only in one season, From. April to December there may be no

stations heard but locals, but thereafter the signals come: rolling in at good strength from the four corners of the earth. Static is not as a rule so troublesome, but a curious effect known as "skip-distance" is felt on this band. A high-power station 100 miles off may come in at much less strength than a similar one 1000 miles away, because of the reflection of the waves by the Heaviside layer. Fading is occasionally bad on this band. Daylight is better for reception, as signals begin to fade out with the approach of darkness. It‘may puzzle some readers as to the procedure of making contacts between amateurs speaking a different language. However, all amateurs use their international abbreviation language with English as a basis, and all foreign hams know this. Another interesting point is the time difference between countries. It is quite common for the amateur at one end of a contact to be about to go to bed, and the other to work, as in the case of N.Z. and U.S.A. Securing Stability. Qu the higher frequencies (shorter wavelengths) the adjusting and tuning of the transmitter and receiver

becomes more critical. It becomes harder to maintain a good note and stability of signals. In a single valve, or "Self-excited" transmitter, there are several factors which sometimes cause the signal to vary slightly in frequency. If the valve is at all overloaded (i.e.. the input is too great for the valve) heating of the elements will cause them to expand, thus’ changing the capacity between them, and making the signal "ereep"’ in frequency. Also, swinging antennas or fluctuations in the plate or filament power supply will wobble the signal. These difficulties are not great in a sensibly-designéd ‘and: operated transmitter, but to-overcome them and secure absolute frequency stability there has arisen in recent years a type of transmitter known as "erystal-con-trolled." . "The Basis of this type is a smal quartz plate, ground to a definite thickness, which entirely controls the frequency of the oscillating tube cireuit in which it is connected. Only changes in temperature will cause its frequency to change. The power to this "crystaloscillator" is very low and is kept con-

stant, thus avoiding heating. The output of the oscillator is then fed into a graduated series of R.F. amplifiers, each "exciting" the next one. Each amplifier is simply a transmitting valve, arranged to amplify, and the final one couples the power into the antenna. Nearly all broadcast stations are cry-stal-controlled, and many amateurs use this method on a smaller scale, but it is too complicated for beginners to touch. There are dozens of other interesting factors in the amateur game besides shose mentioned here. Space does not permit of more being described, but they will all be met with when one gets on the air. In all phases of radio it ts experience that counts, and especially

with the ham. For a really live hobby there is none to better amateur oe mitting, for metaphorically "His is t world, and all that’s in it." To a followers of these articles, the writer wishes good luck and 738.

"Q" SIGNALS

QRA-Location of station, Q@RH-W avelength. QRI-Tone of signals. QRK-Sirength of signals, QRM-Interference. QRN-Siatic. QRO-Higher power. QRP-Low power.

QRS-Sending slower. QRT-Stop sending, QRU-Nothing further. QRX-Waiting. QSA-Readability. QSB-Fading. QSL-Acknowledgment, Q@S0-Contact,

ARRREVIATIONS

sked-schedule sri-sorry TOA-to-day ths, tnx-thanks U-you ur-your vy-very wen-when wkd-worked wl-will wx-weather . Xmitr-transmitter YL-young lady. 73-Best wishes abt-about agn-again amt-amount ani-any BCL-broadcast listener

B4-before BK-break BN-been | CK-check . CKT-circuit -cond-conditions cud-could cul-see you later cum-come em-them es-and FB-fine business | FM-from GA-go ahead GB-good-bye GE-good evening gud-good Hi-laughter hr-here hrd-heard

hv-have ‘hw-how mani-many nd-nothing doing ng-no good nite-night | NM-no more nw-now OB-old boy OM-old man op, opr-operator OW-old woman . (wife) pse-please pwr-power 0.K. Rpit--report, repeat sa-say sed-said sigs-signals