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Bredhurst Receiving and Transmitting Society

FLC title

Operating Practices & Procedures Theory

The key to the FLC is the "practical" aspect of this section as you not only have to learn how to answer questions on operating practices and procedures, but will also need to be able to demonstrate competency in operating amateur radio equipment as part of your practical assessment.

The Theory for the written exam

The Operating Practices and Procedure section of the course is designed to prepare you for successful and competent operation of an amateur radio transceiver using the accepted conventions of operation that have been on the amateur bands for many years. The training is also intended to make you feel at ease with operating as you will know what to expect of others and what others will expect from you.

The Practical Assessment

The first thing to note is DON'T PANIC - the practical assessment is designed to make sure that you can set up a station and operate safely and with courtesy to other radio users. You will be taken through the practical assessments in this section with a licensed amateur who may well still remember their first time on the air and how nervous they were!

In order to complete these tasks your tutor should first show you what is required with regards to setting up a radio station, you will be asked to setup a radio station (ie connect all the cables and leads up in the correct order for safe and reliable operation). Then you be asked to make radio contacts - on VHF FM and on HF SSB. The operation on FM is subtly different from SSB and you need to show that you manage the differences for yourself.

At the end of the practical assessment you and your assessor should be confident that you can do these tasks yourself without any supervision (once you have your license of course!)

It is worth repeating that for all of you that have come into the hobby from CB - please do yourself a favour and consider only using those expressions you have come to love like "give us a 9" or "10-4" etc when working on CB and NOT on amateur radio bands. There are many amateurs who do not like such CB expressions even though they freely use similar expressions which may be exclusive to the amateur bands.


8. Operating Practices and Procedures.

8a Operating practices and procedures

8a.1 Understand why one should to listen before calling and then ask if the frequency is in use.

It is often said that the first rule of operating amateur radio is to listen, the second rule is to listen and the third rule is to listen again! It is important to check that the frequency that you are about to talk on is free - i.e. that no-one else is currently talking on it. That may seem obvious, but when you consider that there may be a conversation taking place between 2 people - one of which you can hear ( and can therefore hear you! ) , and one of which you can't - how do you know if it's free?

Well, the first rule is to listen to see if there is anyone already using this frequency. Sometimes you can easily hear a station talking and you know that the frequency is in use. Sometimes you may not hear anything, but remember this only means that may be you can't hear them - not that someone else can't.

Consider this simple example - two people are talking on the radio ( in a QSO ) - one in London and one in Oxford ( North West of London ). They have been talking about the hobby and the person in Oxford is now talking. You are in Canterbury ( South East of London ) and listen on the frequency - and hear nothing - that is because you can't hear the person in Oxford. If you were to start using this frequency the person in London would be able to hear you and it would disturb his conversation.

So how do you avoid this - again if you were to listen for long enough you would finally hear the person in London respond and start talking and know that the frequency was in use. The answer is that after you have listened for a while and heard nothing, that you politely and simply ask "Is this frequency in use please, this is G7BRC asking" - or similar words and using your own callsign. Please remember to keep this call short and to the point as you may be interrupting another conversation, and to include your callsign as after all you are now transmitting. If the frequency is clear you will hear nothing - if it is in use you may hear something like "This frequency is in use" or "Please QSY, frequency is in use" come back to you. Do not respond ( you don't want to interrupt their conversation again ! ) but move onto another frequency and try again.


8a.2 Recall how to make a CQ call.

Radio amateurs use a code of abbreviations that stem back to when most conversations were held over Morse code - and these abbreviations were used to shorten the amount of letters that had to be sent as part of a message. A lot of these are still in use today. The first of these that you will use is "CQ". CQ is the call that radio amateurs use to invite other amateurs to have a conversation ( or QSO ).

How you call CQ depends on which frequency and / or mode you are using.

In a nut shell when there is a calling channel such as on 2m FM the CQ call can be much shorter than for that used on SSB on HF where the station needs time to tune into your signal or even for that matter on the SSB calling channel on 2m where again your signal would need to be carefully tuned into by the receiving station. On VHF, when we use the FM mode, we have defined "channels" that we use. This means that I don't have to search for anyone calling all through the frequency range - i.e. I can just search the defined channels. This makes finding someone calling CQ very quick and easy. In fact there is even a standard calling frequency on certain bands ( such as 145.500MHz FM on the 2m band ) that you use to call CQ. This is a shared frequency that is used by all radio amateurs, so you do not need to ask if the frequency is in use before using this calling frequency. If you were not using the standard calling frequency you would be expected to check if the frequency is in use before calling CQ. You also should not call CQ when someone else is talking ( such as calling CQ themselves ) on the calling channel.

As it is so easy to find someone calling CQ when using these defined channels. You do not need to make your CQ call very long. If someone wants to respond to you, they can find you and respond very quickly.

On FM therefore, your CQ call may sound like this:

"CQ, CQ, CQ, This is G7BRC, G7BRC calling CQ and standing by for any contact"

You have called CQ, given your callsign ( in this case twice in case anybody didn't get it first time ) and stated that you were looking for anyone to have a conversation with. Do not speak too quickly. You know your callsign but if you say your callsign quickly those listening may not hear it clearly and decide not to give you a call. Use the proper Phonetic alphabet of the letters Golf Seven Bravo Romeo Charlie.

If you get no response after a short period you may try calling again. However do leave a reasonable gap for someone to respond to you, and also so that someone else can also come in and put a call out ( they may be calling for a certain individual rather than an all stations call such as CQ ). Remember you are sharing the calling frequency on the FM modes. If after 2 or 3 attempts no one has responded, either move to a different band / mode and try again, or leave it for a while. You will not get anyone responding to you just because you keep calling, in fact it may put people off talking to you!

Once you have made a contact on the calling frequency you must move off that calling frequency so that other may use it. This is described in more detail below.

extra logo

You may also call for a specific person rather than call CQ ( which by definition means a call to all amateurs ) by giving their callsign in place of the CQ call. For example if G7BRC wanted to call G0BRC on VHF the call would be:

"G0BRC, G0BRC, this is G7BRC, G7BRC calling for you". This would indicate to other amateurs that you were only interested in hearing from G0BRC.

On the HF bands, there are no defined channels and people are free to hold conversations anywhere within the agreed ranges specified on the band plan. This also means that there is seldom an agreed calling channel that you can use to make a call ( although for some modes of operation such as SSTV / low power operations etc there are calling frequencies defined and agreed upon ).

As there is no one place to tune to in order to look for someone calling CQ, radio amateurs scan ( or search ) through the frequency band trying to find someone who is calling CQ so that they may respond. As this searching can take a long time ( the bands are quite large so you have a lot of frequencies to search ) and tuning to the exact frequency is slow ( as you will find out, tuning accurately to a SSB signal takes some practice ) you are expected to make your SSB CQ calls longer to give someone time to find you.

Call CQ on SSB and particularly HF

A good rule of thumb when calling CQ is the "three times three" rule. This means that you call CQ three times, give your callsign three times, then repeat the whole procedure three times. Your CQ on HF may therefore be like this:

"CQ CQ CQ, this is G0BRC, G0BRC, G0BRC calling CQ.

CQ CQ CQ, this is G0BRC, G0BRC, G0BRC calling CQ

CQ CQ CQ, this is G0BRC, G0BRC, G0BRC calling CQ and standing by for any contact."

Remember that you should have checked to make sure the frequency was free before calling CQ!

If anyone has tuned into your signal and wants to respond they can do so now. If after a few seconds have passed by no-one has responded then you are free to call CQ again. This is a balance between giving other amateurs a chance to respond, and waiting too long so that anyone who is searching through the frequency misses you because you are not transmitting. In this case, 3 or 4 seconds is enough time to wait before calling CQ again. You may repeat this as many times as you wish while waiting for a response.

If / once you get a contact, you do not need to change frequency on the HF bands. You are said to "for the time you are there to own" the frequency if you first checked it was clear and made the CQ call. The frequency is yours until you choose to give it up.


8a.3 Understand the need to move off the calling channel (when on VHF/UHF) once contact is established.

logoWhat is the Calling channel? If you look on the band plan for the 145MHz (2m) if you look at the frequency 145.500 against it you will see V40 and FM calling channel. The V40 means channel 40 and the calling channel means that is where you tune your rig onto so that you can listen to the calling channel for stations or where you call CQ your self.

As described above, the VHF and UHF calling channels are shared between all radio amateur users. This means that if you were to make a contact on the calling frequency and stay on that frequency whilst holding a conversation, you would be stopping other users from calling on that channel. It is therefore necessary to move to a clear frequency once contact has been established with another radio amateur so that you can continue the conversation without interfering with other users.

You will most likely come across codes used by radio amateurs, namely QSY. QSY means to change frequency or channel.

This is the point where many new radio amateurs think is complicated - but it's not! Just remember that all you want to do is find somewhere quiet (i.e. a free channel) to continue your conversation. If you look at the mock conversation below, we have highlighted the steps that you may take the move to a clear channel.

a) You call out asking if anyone wants a conversation:

"CQ CQ CQ This is G7BRC, G7BRC calling CQ and standing by for any contact"

b) Another radio amateur responds:

"G7BRC this is G0BRC returning to you over"

c) You would acknowledge the response and ask the other radio amateur to wait while you find a clear channel:

"G0BRC this is G7BRC, thank you for coming back to my call. If you would like to wait here I will go and find us a clear frequency, G0BRC from G7BRC"

d) The other station will probably just wait for you to go and find a free frequency or may quickly respond to say that they will wait for you.

e) You now need to change channel and try and find a clear frequency. For instance you may change channel to 145.450MHz (which is 2 channels below the calling frequency) and listen to see if it appears free. If it is you would put out a call to make sure that the frequency is clear:

"Is this frequency in use please, this is G7BRC asking". If nothing is heard you would change channel back to the calling channel - if someone responded on this new channel you would change frequency again and go through the same procedure of listening and asking to ensure the frequency is clear.

f) Once you have found a clear frequency you change back to the calling channel, and making sure that no-one else is speaking you would say:

"G0BRC this is G7BRC, please QSY to one four five decimal four five zero, over"

Note that it is common practice to say "decimal" rather than point - for example 145.450 is said as "One Four Five Decimal Four Five Zero".

Also it is just as valid to say:

"G0BRC this is G7BRC please change frequency to one four five decimal four five zero, over" - you don't have to say "QSY" if you don't want to.

g) The other station is likely to confirm this change of frequency :

"G7BRC, G0BRC, roger QSY one four five decimal four five zero "

h) You then change to 145.450MHz - the frequency you found was clear, and ask again if the frequency is still clear:

"Is this frequency in use please, this is G7BRC asking" - remember you have been away from this channel for a couple of seconds and someone else may now be using it. If it is busy it's best to ask the other station (we use station to mean a licensed radio amateur) to go back to the calling frequency and trying to find another free channel.

g) It is good practice for the station you are now in conversation with to also ask if the frequency is clear as they may be able to hear other users that you can't. Be aware that some of licensed amateurs (even those that have been licensed for many years) forget to do this! So they should call:

"Is this frequency in use please, this is G0BRC asking".

If you are both sure that the frequency is clear, you can start your conversation for real. As with any conversation there are no strict rules that say what you should say, but most amateurs like to exchange signal reports ( which we'll come on to shortly ) and some personal information, such as your name and location.

EXTRA for VHF and UHF chanelised operation

In a discussion with another amateur, who had been licensed for a long time, remembers that years ago that you were taught:-

  1. find a clear frequency first by going through the above procedure and

  2. then call CQ as indicated above

  3. when you gained a response you would have been able to tell the other amateur to QSY to what ever frequency you had found was clear earlier and

  4. make one final check before starting your QSO.

EXTRA GENERAL

Please be aware that you should not give out too much personal information, as you do not know who is listening to the conversation. In particular you should not give out your surname ( as they may be able to use this to find where you live ), your address, your age ( especially if you are under 18! ) or any information that may be used against you. For example don't tell anyone that you are going out for the evening and leaving the house empty, or going on holiday. Again, remember you never know who is listening to your conversation! Don't let this put you off amateur radio, as there is still much fun to be had and lots of new friendships to start.

Whilst for the exam point of view from the licence section the Period of communication = the whole QSO for good operating practise Period of communication = each over.

From the point of view of "good operating practise" it is considered wise to adopt the use of giving your callsign at the beginning and end of every over unless the over is very short.

8a.4 Recall the phonetic alphabet.

ITU PHONETIC ALPHABET:

A

alfa

H

hotel

O

oscar

V

victor

B

bravo

I

india

P

papa

W

whiskey

C

charlie

J

juliet

Q

quebec

X

x-ray

D

delta

K

kilo

R

romeo

Y

yankee

E

echo

L

lima

S

sierra

Z

zulu

F

foxtrot

M

mike

T

tango

G

golf

N

november

U

uniform



The numbers





0

zero

1

one

2

two

3

three

4

four

5

five

6

six

7

seven

8

eight

9

nine





DECIMAL POINT..

decimal

FULL STOP

stop

The sort of question in the exam could be :-

Q. Using the phonetic alphabet spell "radio"

Answer Romeo Alfa Delta India Oscar.


8a.5 Understand that the transmission of music and the use of offensive or threatening language whilst on the air are unacceptable in amateur radio.

Note it says here UNDERSTAND. Then read again the text in blue and it is self explanatory. Amateur radio is a hobby and not a soap box for you to act out your stage skills or lack of them, so do consider what you say over the air. Using offensive or threatening language on the air will not be tolerated by other amateurs and the authorities who govern the air waves ( OFCOM ) could have cause take action with regards to your operating.

8a.6 Understand how to respond to music or inappropriate language overheard or received from other stations.

You are not the policeman or policewoman of the air ways so the best response is NONE. Say nothing and do nothing to make the situation. If you feel so inclined shut down your station and do something else. The person using the inappropriate language will not know why you have gone QRT and without reply is left just talking to themselves which as you will have learned elsewhere is broadcasting and not permitted unless calling CQ.


NOTE: The item 8a.7, below,  will not be examined as at February 2015 .

8a.7 Recognise the advisability and common practice of keeping a log and items recorded.


page of a log book


8b Operating through a repeater.

8b.1 Recall that repeaters are mainly intended to extend the range of mobile stations.

Recall how to use a repeater and understand the need for an Access Tone or CTCSS and frequency offset.

In the UK we live in a country that has many beautiful natural features (such as hills, mountains and valleys) and many man made features ( such as houses, apartment blocks, office blocks, shopping centres etc ). These features can greatly increase our quality of life, but can often block radio waves from travelling!

In our homes we often put up antennas at a high location so that we can "see" over these features ( or obstacles as far as radio waves are concerned ) and make contact with other licensed amateurs. Unfortunately, whilst operating mobile we aren't always able to do this. If we try and operate from a mobile station that is surrounded by high buildings, or which is situated in a valley, the effective range is limited as the radio waves cannot get through the obstacles. In this situation, we use a radio repeater.

A repeater is designed to operate on the mode FM and to effectively increase the range of anyone operating mobile.

A repeater does this by:

>a) Being placed "high up" - often on top of a hill - so that it can "hear" or "see" further.

b) Having a large and effective antenna system. This ensure that not only can the repeater hear your signal, but also that the signal it puts out is strong so that others can hear it.

c) Having a sensitive receiver and powerful transmitter. As above, so ensure it can hear you, and that other can hear it.

An animationshowing how a repeater can be used by two mobile operators who do not have direct contact due to a hill in the way of their VHF signals, so the repeater on the top of the hill can relay the message from one station to the other in real time of the communication of the originating station.

Place your mouse pointer on the diagram above to see the operation of a repeater.

A repeater listens on one frequency ( called the input channel ) and re-transmits what it hears on another frequency ( called the output channel ). It needs to transmit on a different frequency so that it does not listen to itself - but to the signal that it wants to boost and re-transmit - ie yours!

On the 144Mhz band the difference between the input and output frequencies is 600kHz (or as it would be displayed on your transceiver 0.6MHz ). I.e. the repeater listens on a frequency that is 600Hz below the frequency that it transmits on.

In radio terms, these frequencies are quite close together, and the repeater needs quite complex and sophisticated electronics to make sure that it can still hear the input signal when it's transmitting on the output frequency.

The repeater does not continually transmit however, but only transmits when it is sure that someone wants it to. In order to tell the repeater that you want it to retransmit your signal, you need to tell it to "wake up" by one of two methods.

The first method is to send a short tone (called a Tone Burst) at 1750Hz to the repeater at the start of your transmission to tell the repeater that it should be retransmitting what it hears from now on. The repeater then "wakes up" and will continue to retransmit the signal whilst it still hears someone talking on the input frequency. It also allows for small gaps so that one person can stop talking and another start talking without the repeater needing to be woken up again by a Tone Burst. In this way only the first person talking needs to wake up the repeater. Most mobile transceivers have a method of generating this Tone Burst, but the method of calling this function will vary from transceiver to transceiver, so it not covered here. Please also be aware that the tone needs only to be about 0.3 to 0.5 seconds long - so just "jab" the button!

The second method, and the one that is preferred today is to use a function called CTCSS. CTCSS stands for "Continuous Tone Coded Squelch System". The idea behind the system is that instead of generating a tone at the beginning of the call ( as the tone burst does ) your transceiver continuously generates a tone that it "hidden" in your transmitted signal. The tone is a low frequency "hum" ( between 67Hz and 118.8Hz - don't worry, you don't need to remember these figures ) that the repeater listens to and when it hears the correct tone will start to retransmit your signal.

The advantage of CTCSS can be seen from this simple example. Suppose that you are in a car and want to operate mobile via a repeater. Unfortunately, there are two repeater within range that operate on the same frequencies. If you used the tone burst function you would wake up both repeaters and they would both start to retransmit your signal. CTCSS is designed however so that even if two repeaters are operating on the same frequency, they are listening for a different coded tone ( ie the hum ) as part of the signal. Now when you transmit, both repeaters will hear you, but one will listen to the tone, decide you are not trying to access it and not retransmit your signal, while the other repeater will hear the tone that it wants, decide that you are trying to access it and retransmit your signal. Also in operation, once set up, CTCSS is easier to us as you don't have to "jab" the tone button. CTCSS is often more complex to configure on the transceiver though.

Although you do not need to show that you can do this yourself, your instructor should take you through setting up a transceiver to use a repeater. This will include setting the transceiver to transmit and receive on different frequencies as well as setting up the CTCSS functions.

One last thing you should know about repeaters is that they have a built in safety mechanism that stops then continually transmitting. The repeaters have a "time out" period after which they will stop retransmitting your signal. This time out varies between repeater but is normally between 2 and 5 minutes. You must therefore keep your "overs" short so that the repeater does not time out. Once you have stopped talking and have released the PTT key, the repeater re-sets its clock so that the next person can start their "over" with their full allocation of time. Whilst operating through a repeater you should therefore keep your overs short, and wait for the repeater to reset after someone has just used it - this is normally identified by the repeater giving a series of tones (normally a K in morse code) to say that it is ready for the next user.

Echolink, IRLP and EQSO

In addition to the "standard" repeater there has been for some time and coming online more and more repeaters and other simplex stations which are linked to the Internet (and used exclusively by licensed radio amateurs sometimes linked via the computer).

One of the first 2m internet linked repeaters was GB3IR in Richmond, North Yorkshire, but others exist at Nottingham GB3IN and Amersham GB3AL. By the use of DTMF tones once you have a link to the repeater you can call the world by keying in appropriate node numbers. Echolink nodes have four or more numbers and are sometimes prefixed with a * to call them (but this all depends upon how the station you are calling through is set up), IRLP nodes are simply 4 figure numbers. Any number greater than 4 will be an echolink node and thus may need to be prefixed by the *.

GB3IR has the Echolink number of 1353 (but may need the * to access from certain repeater /simplex links) and IRLP node number 5562 but you only need those numbers if you want to call GB3IR from a distance away via another internet linked repeater, or through your internet echolink on your computer.

If when licences you have an internet link and join Echolink then you can access the repeaters via your computer or via a 2m link.

Additionally there are 70cms internet linked repeaters doing the same job as those mentioned above.

Working though GB3IR is great fun for all whether mobile or internet based as one moment you can be talking to Uk the next VK (Australia) or any of the other far away countries.

More information is available from the internet by searching for Echolink or IRLP or EQSO.

For more info on GB3IR click here.

A diagram showing how Echo Link can link a station in UK via the internet to one in Australia.

Watch the animation for more information as to how the system works.


8c Band plans

8c.1 Recall why band-plans are used.

Identify items on a published band-plan (eg. calling frequencies and recommended modes).

Band plan

Many students, in the past, have not given nearly enough attention to the detail of the Band plans and loose easy marks. Please make sure that you know how the band plan works and what is the meaning of the information contained there in.

The band plan for 14MHz shows you a lot of information that fortunately you do not have to learn but you must have a full understanding.

The first column shows you where in the band the preferred modes should be operated. note particularly the section on Beacons as operating in that section is a definite no no as it is reserved exclusively for a set of beacons located around the world that are linked to the atomic time signals so that they give their CW ident at the same time every time and do not overlap each other.

The centre columns indicates the Max Bandwidth and UK mode usage

The right hand column goes into more details as to what operating can be done where.

This band plan for 14MHz will be available to you in the written assessment.

The band plan for 144MHz is possible even more complex than that for the 14MHz band and certainly has a great deal of detail.

So to remind you again :-

Please ensure that you obtain a paper copy so that you can look through the chart carefully.

Be aware of what it contains and then you will be ready for any questions relating to the chart and then you can just look up the answer.

You could have a question that relates to anything shown on the Band plan.

Too many students are losing marks it is assumed that because this paper work will be with you in the exam that they do not both to look at it in detail

The Band Plan is a document that lays out the various modes and operating frequencies within that legal allocation. The Band Plan is operated voluntarily, but should be adhered to. It's purpose is to ensure the most effective use of the limited radio spectrum that we have available to us.

The schedule and band plan will be provided to you during the written examination and the practical assessment, so there is no need to learn it, however you must show that you can understand and extract information from it.

Some important frequencies in the 14MHz Band Plan

14.099 to 14.101MHz BEACONS ONLY

The beacons are there to help you determine what the propagation is like around the world so you must keep clear of those frequencies.

Some important frequencies in the 144MHz Band Plan

144.300 MHz SSB calling - this is the frequency that all station call initially on SSB and then QSY unless it is a contest when you will hear stations calling additionally on other parts of the band.

144.600 MHz RTTY calling frequency with the working frequencies either side of this centre frequency.

145.500 MHz FM (mobile) calling - in fact this frequency is used by all operators as a calling frequency whether mobile or fixed.

145.525 MHZ RSGB News frequency ON SUNDAYS ONLY so best keep clear !!

145.550 MHZ Rally and Exhibition "Talkin" Frequencies.


8d Connecting microphones and other audio sources to the transmitter.

8d.1 Recall that connecting anything other than the supplied microphone (e.g. packet radio TNCs) to the transmitter requires correct operation of the PTT line and correct audio signal levels.

Most transceivers use a microphone that is attached to the transceiver via a removable plug. This plug may be a round type, or may be a newer "modular" or square type - similar to a telephone cable plug. In either case, the microphone supplied with the transceiver has been specially matched with the transceiver itself.

During your practical assessment, it would be a good idea to look at the microphone plug on the transceiver you will be using.

The role of the plug and socket is to make sure that the correct signals from the microphone are sent to the correct parts of the transceiver. At a minimum this would include the signal that says when the PTT switch has been pressed, and the audio signal from the microphone itself. With many transceivers the microphone also has various controls ( such as channel up and down buttons, scan buttons etc - some now have all of the controls of the main control panel duplicated on the microphone ) that also have to be connected to the transceiver in the proper order for their correct operation.

If any of these were incorrectly wired, the transceiver would not operate correctly. At worse the transceiver could be told that the PTT was depressed when it was not, and the transceiver put into transmit mode continually. At best the transceiver would simply not operate.

There are a number of different accessories that you may wish to connect to the microphone socket of the transceiver. These may include:

i) A TNC - Terminal Node Controller. This is an interface between the transceiver and a computer / terminal which allows the transceiver to operate Packet a digital modes. The TNC controls the PTT and the sound levels which it sends to the transceiver. It will be necessary to check the audio level from the TNC is correct and not over driving the transceiver and that the PTT properly keys the transmitter so that it operates properly.

ii) A different microphone. Most transceivers are supplied with a suitable microphone to operate, however there are different types of microphones that you may think are more suitable for your use - such as one built into a headband / headphones, a desk microphone, a handsfree microphone ( normally for in car use ) etc. Depending on type they may come with a built in PTT switch or use an external switch, and are likely to have different audio signal output levels - ie they generate different signals when you talk than the original microphone did.

iii) Sound Card interface. Many digital modes ( such as PSK31, SSTV, RTTY etc ) can be generated on a computer and fed to the transceiver for transmission. The computer would therefore control the audio signal levels and the operation of the PTT. It will be necessary to check the audio level from the Sound card is correct and not over driving the transceiver.

When connecting anything other than the supplied microphone you must ensure that:

a) The PTT line works correctly. This means that the transceiver will transmit only when commanded to operate PTT line especially when it is triggered from a TNC or computer ) and will return to receive when the PTT line is released.

b) The audio levels are correct for the transceiver. Too little level would mean that you are not heard, too high a level would mean that your signal was distorted, and you would not be understood.



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