Bredhurst Receiving and Transmitting Society |
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Operating Practices & Procedures ADVICE |
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CB roots A note for all of you that have come in from CB - please do yourself a favour, when you obtain your Foundation Licence give up using those expressions you have come to love like "give us a 9" or "10-4" or your signal is giving me 5lbs etc, when talking on amateur radio, even when it is to your friends who have also come into amateur radio via CB but even . There are those radio amateurs on the bands that will not like nor understand such CB expressions. However to quote some advice heard on the amateur bands :- "The only serious conviction that a person should have is that nothing should be taken too seriously." So when you feel an anger moment coming on do suppress it on the air waves as it is not your duty to be the local policeman on air - it is better that you should show by your good operating practice how others should operate. Listening So after those words of advice where should you start your operating - by listening and more listening. You can learn more by being a SWL (short wave listener) before you obtain a licence than from attending lesson after lesson on operating practice. You will soon learn that listening on FM channelised frequencies is much easier to hear the QSO (the chat) than on the SSB unchanalised frequencies. Now you may be saying that you do not have a receiver etc etc - so the answer is to join a club and ensure that they have equipment that you can use during meetings. At the Brats we hold weekly meetings and many times there are those who want to operate / listen to QSO's and also during the summer the Brats hold field weekends where again you can listen into stations. When you listen to SSB you will hear single tones at times and then going on and off, this is likely to be someone tuning up and often you will hear this right on top of a station who is working another station. Why does this happen - because of incompetance of the operator tuning up just because he / she may not realise what disruption they are causing. Do not be an operator like that learn to tune on a clear frequency! Tuning There two parts to tuning :-
The Rig Properly tuning a modern transistor PA SSB rig take time to learn how to operate especially if there are filters to aid reception. You have then not only to be able to tune to the signal but to get the best audio then you have to learn how to use the filtering. Sometimes you will find that a rig also has an RF attenuation control, which exists on some transceivers, which can cut out many associated signals just off tune but heard without the filters in place and then by using the attenuation, to reduce to total RF received, makes the wanted signal even easier to hear. This is more difficult to write than to demonstrate!!!! Complexity increases if you buy a second hand valve rig as you will then have to learn how to tune up the output from the valves - but discussing that here would need more than just a few paragraphs so consult your local club if you plan to run a value rig!!! Even a relatively modest modern rig such as the Alinco DX 70 which can be used as a main rig and can be used as a "holiday" radio (that is a radio which is taken on holiday when you work /P) and then by the use of the attenuation and the single filter control you can dig out many signals from the noise. Another control to understand the use of is the IF control. By practical experience you can learn how to adjust the received signal and cut out an immediately adjacent signal. It is hoped that this has given you some good advice as to how to participate in amateur radio even before you have a licence to transmit. The ATU The ATU is used to match the antenna to the 50 ohms impedance of the rig. The way not to do it is to tune to a station and then decide to tune your ATU by transmitting on that frequency and making the adjustment. The correct way to tune the ATU is to locate what appears to be a free frequency and on the lowest power available to you press the PTT and assess the amount out of tune. Remember that you have to tune with a signal going out and the easiest to use is an FM or AM signal as an unmodulated SSB signal will not show on the meter as it is only when there is audio on the signal that the transmitter signal has any power leaving the aerial. So decide which you want to use and if you rig have no FM or AM then you will have to whistle into the mic or it you have RTTY tones then key those and you will have the signal to use. (Remember with RTTY tones you can only have the power out level at 50% of the maximum the rig can use on SSB but with the limitation of the power allowed by the Foundation Licence this should not worry you initially). An untuned match between aerial and rig will cause low power into the antenna and a high SWR. Where as a properly matched antenna to the rig will show a higher power output than initially and low SWR due to low reflected power. Of course you will need to have an SWR UNIT either in your rig or in the atu or if separate then linked directly to your rig by a patch lead and then the SWR connected to the ATU and then lastly the aerial attached to the ATU. By operating the PTT at low power you will do little to upset other operators and then you will need to practice the tuning of the controls on your ATU. Usually there will be two controls one that will move the reflected needle of the SWR unit greatly and one that seems only to move it a little. Then as you tune the movement of the control may reverse round the other way. Only practice will ensure that you achieve the ability to tune the antenna to the rig quickly and cause minimum disturbance to others. In fact in the course you will learn that the ATU does not actually tune the antenna but merely alters the impedance so that it matches that of the rig. Having "tuned" the aerial to the rig even putting up the power will have little or no effect on the SWR but with higher power the error of tuning the ATU shows up, so do not think that it is an operator error but just fine tune it. Then when really tuned you can move back to the frequency and call other station etc etc AND you will not have interrupted any QSO and will not have annoyed anyone!!! Have Fun... The important thing in amateur radio is to have fun and enjoy the fun there is to have... ANY QUESTIONS ?????? Due to spammer the email information is as a graphic
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