Amateur Radio Voice-Links via the Internet
On this page : DTMF, eQSO (M0ZPD), EchoLink, iLINK, IRLP, iPhone, Mic Settings, Opinion, URLs
Fancy using repeaters worldwide?If you could dial a phone number for the same cost as your internet access, and use amateur repeaters in the USA, Australia, the UK and other parts of the world by remote control, free of charge, would you? Of course you would! No radio required, no Morse tests (hehe), but all the fun of amateur QSOs with the thrill of knowing your voice is being heard on 444 or 147 MHz (for example) on the other side of the planet! You can do this RIGHT NOW, only not with a telephone...
You already have the bits......Nearly. If you already own an amateur licence, and an internet PC (of course you do!) with MS Windows 95 or later (except NT4!), a soundcard and microphone, then you're just one short step away. All you need to do is download a FREE small program such as eQSO or EchoLink, run it, enter your callsign, wait a moment or three for registration, and away you go. It's THAT simple, and great fun.
Even a PC that's VERY slow by today's retail standards will do (any Pentium), and 'dial-up' internet access over a standard 56k/33.6k modem connection is fast enough. I had no idea it was so easy, until I installed iLINK on my lowly sub-300MHz PC on 11th Jan 2002 after a very quick download, so here I am trying to spread the word, let's see if I can inspire you to join in.
No radio required...If you've got no radios at the moment and you're just holding on to your callsign for the sake of it, or if you're only just licenced and you're still saving for a radio, or if you've left radio for any of numerous reasons, this is a fine way to get on the air and have some enjoyable QSOs around the world.
... but, WITH a radio :Instead of sitting at the PC with a very un-radio-like microphone, you may be lucky to live within range of a gateway - an on-air radio link or repeater that is connected to an internet computer running eQSO, EchoLink, IRLP or some other linking software. In that case, you can listen out for other amateurs around the world on similar links, or with eQSO/EchoLink systems you'll also hear amateurs using their computers. When you hear such a call start on a Simplex Voice Gateway you can simply talk back on the same frequency once the carrier has dropped. As well as Simplex Voice Gateways, a repeater keeper may have an NOV to link the repeater to the internet (in the UK this may involve some newer ones around 430.9MHz). (may be directly at the repeater or via another operator using the repeater with a link?)
The gateway transmits when there is transmitted audio coming in over the internet, and when it receives your signal it will send that back over the internet to the other end of the link. Speech is sampled into a stream of digital values. This bitstream 'raw' (unprocessed) would be too much for a modem to handle, so to reduce the connection requirements the bitstream is compressed using a codec (COde/DECode) - technology similar to modern cellphones, mp3, Minidisc, DAB, digital TV etc.
Have a listen, and you'll soon realise how easy it is to join in. You'll need to work out which system the gateway is using. If you hear people talking amongst themselves, with no DTMF tones or recorded messages, it is most likely eQSO (the audio with eQSO may have a telltale clackity-clack effect). In that case you can simply transmit whenever the gateway isn't transmitting, and you'll be heard on the system. You will be limited to the repeaters currently connected to the same part of the eQSO system. If you hear people dialling with DTMF, and messages introducing overseas repeaters, the gateway is most likely running EchoLink or IRLP. With these systems you will have to wait until someone calls through the gateway, or learn to initiate connections with DTMF. In all cases you may takes turns with other local stations to form a net, just as there may be a number of stations participating on the other end of the link. Good clear operating practices are beneficial to avoid people 'doubling', considering that gateways are one-way at any moment on the single frequency.
Internet Voice Links were pioneered in the UK by G7WFM (http://www.g7wfm.co.uk) at the end of 1999, on 437.5MHz. Further gateways were later allowed by more general Notices of Variation in Feb 2000. The following frequencies may be allocated :
I tend to use the following terms as the mood takes me (sorry!)...
I'm trying to keep this page up to date, but this area of amateur radio is developing very quickly so I apologise in advance if anything is out of date!
Start a connection, on-airUsing your radio with an 'on-air' link/repeater, no special equipment is required to talk back to an active link, but with EchoLink based gateways you can make a DTMF call to any other such on-air link around the world or active PC-based EchoLink user. (To do this, you will need a radio that features DTMF, the two-tone beeps that are used for telephones dialing. Many recent handhelds have this, look for 0 to 9,*,#,A,B,C and D written by the keys - you press these while transmitting and you'll hear the bleeps).
To see if a silent channel has an active (but standing-by) RF node, try * (or A*) for EchoLink, or 0 for IRLP.
An RF link that doesn't respond to the above may be linked via the eQSO system, or some other.
eQSO by M0ZPDHomepage and downloads : http://www.eqso.net
Current (2003-dec-11) PC Version : 1.20 (2003-nov) widescreen ver now available
Written by Paul M0ZPD, this software started off as the 'M0ZPD Internet Gateway' system, but was re-branded on 19th February 2002 as eQSO (which means EarthQuake gas ShutOff to some people :o) as a Google search reveals).
eQSO in action (version 1.12)
eQSO is a system where gateway link stations and PC users can chat amongst themselves, connected in a virtual 'rooms'. A gateway may be in a room on its own, waiting for other gateway operators to join it, or PC stations. Sometimes more than one gateway will be in the same room, so linking different radio channels together in several locations around the world. When anyone in the room speaks into eQSO, they will be heard by all the other stations in that room - possibly being broadcasted simultaneously on various channels around the world.
On a PC, running the eQSO client software, it will probably be obvious what's going on and it's a lot easier to figure it out than to explain it here! Listening to an on-air gateway could be a bit more baffling to someone new to it all, but basically there may be several such gateways all connected together via a named eQSO 'room' on a given internet server, and you'll hear people talking from who knows where - you'll just have to pick up from the conversation (and callsigns) as to where they are and whether they're using a radio or sitting at a PC. You will only hear people talking when the room is being used. If you're quick you might even be able to join in - but it's first come first served. On a PC you'll know if someone else has beaten you to it as you'll hear them talking (and your callsign won't be the one that's hi-lighted), but on a radio you might find that you end up talking to yourself - doubling with the gateway is when it's transmitting at the same time. This can be frustrating but isn't a usually a problem if you've initiated the QSO and the other party hands passes the conversation specifically to you.
In the UK many gateways are all linked together in '101ENGLISH' with numerous PC stations listening in, perhaps joining in too. A gateway may be in a more obscure room, you won't know from listening on your radio unless you hear someone talking about it, or if you ask.
Thankfully, PC-based eQSO users can join in easily, without saying a word. eQSO feels like an open system where anyone can enter the 'room', listen in, and join in as when they want to. This makes it THE program for the eavesdropping enthusiast, as you can put "Just Listening" or "RX only" etc by your callsign. An amateur hosting an EchoLink RF link would be monitoring a system that is silent until someone uses the radio channel, or until another station specifically calls in over the internet (which could be a random call from another RF station). An RF linking amateur favouring the eQSO approach would be always logged into one of many 'rooms' where any number of other stations are welcome to join in. Any local radio users would automatically hear whatever is happening in that room, and can join in, but cannot change to another room. EchoLink seems (to me) to be a 'service' provided to the local amateur community that allows them to work around the world under their own control, whereas eQSO is a different kind of 'service' that is essentially allowing the local amateurs to listen in to a net where anything might happen, and join in, but with less control.
eQSO is quite straightforward when you get the hang of it, and probably better than EchoLink was for beginners, with a more standard Windows interface (EchoLink later solved that problem) and arguably less complication, combined with the ability to just listen in while getting the hang of it.
To start, load the eQSO software, enter your callsign and a comment, select a room (everyone meets in 101ENGLISH it seems) and press connect. From version 1.12 (February 2002) finding an active room is even easier, with the new "See Who's on the system" button - this loads a new window (monitor.exe) titled "eQSO System monitor by M0ZPD" showing a 'tree view' of active servers, rooms, and users (links/repeaters/PC users). A user's icon changes colour when they are talking, making it a doddle to find the action. Click on a room, and the "Connect To Selected Room" button at the top will make the main eQSO window connect to that room.
The "See Who's on the system" monitor window from v1.13
Having joined a room, you may hear a QSO right away, or it may be that no-one is talking. Click the PTT button and hold the mouse button as you talk OR hold the space bar once the PTT 'has focus' (i.e. is selected), and do remember to use your callsign if there is an on-air gateway in the room, as you will be being heard on the air somewhere. Press disconnect when you're finished, or if want to change to a room on another server. The "Connect" and "Disconnect" are the only buttons you'll need (and possibly the "Room" 'drop-down list') within the Connection 'frame' (a frame is a box drawn around a group of related controls). "Connect/disconnect" refer to the server, not the server/room combination, so changing rooms doesn't require a re-connection. Server details may be stored in presets, but this has been made somewhat redundant with the new "See Who" button / Monitor window.
The "Callsign / Comment" frame can be used during a connection to change your comment. Type in your message (useful to say something when someone else is talking) and press the "Send" button. Again, I find this clearer than the iLINK method (sorry Graeme!).
If you've no amateur licence, you can only listen in to eQSO (probably identifying as SWL-something). However, if the room does not contain any on-air gateways you will not be relayed on-air and so you are free to chat privately to other PC stations. If something goes wrong, those who run gateways (who have to be monitoring their station) can disconnect you. eQSO is even being used on other, non-amateur radio networks such as CB, although these are private and will not appear in the system monitor.
I'm not sure the audio is as good as EchoLink but it works well enough. There tends to be a click-click-click with the incoming signal, and anyone talking too loudly and clipping results in quite horridly loud distortion in my headphones (this depends on the sound card apparently, with my wonderful SB-Live! being one of those that suffers). PLEASE ensure your audio isn't too loud! On the plus side, listening with eQSO seems to make less of a demand on your internet connection, making it possible to download webpages at the same time - with EchoLink this makes the reception choppy or halted altogether. I'm told this is due to a two-way connection with EchoLink whereas eQSO in some way uses one direction at a time - I must admit I haven't yet got a clue about this so I'll do some investigating :o)
This is a system I can see myself using quite often, when I'm not feeling all that talkative. Otherwise, I'll be in EchoLink when I specifically want to work particular distant repeaters. There's room for both, iLINK / EchoLink was my first experience of amateur internet voicelinking, but I'm increasingly drawn to the 'casual net' feel of eQSO, with the ability to join in with keyboard comments (EchoLink conferences tend to pass the mic to you whether you want to or not! Hey, just call me Mr Quiet, LOL).
The stations you get to talk to are determined by the server that is used (and the room number of course). The new "See Who" Monitor window will show you all the current servers, prior to version 1.12 lists of other servers were manually maintained by some enthusiasts.
One limitation of current internet technology means that more than some 15 users at once on a server can make things slow down and make packet loss likely. If this happens, try another room on another server - SPREAD OUT A BIT!
Ports : If you're running a personal firewall, it should ask you to accept eQSO's use of port 10024. The system monitor uses port 26000 (usually used for the game Quake).
With all the eQSO server software available, the system would still run even if the author gave up and became a hermit. EchoLink on the other hand needs its author's attention to stay operational.
eQSO can also be used with non-amateur equipment (where this is legal). In March 2003 some UK experimenters
started a system using 446MHz walkie talkies! See www.446user.co.uk for details. (They run their own
server and will not appear on the System Monitor - see their website for server/password/room) Apparently
in the UK this actually does comply with the IR 2009 requirements.
EchoLink by Jonathan K1RFDEchoLink homepage http://www.echolink.org (or http://www.k1rfd.com )
The website is clear enough that I don't really need to add much here, pictures or otherwise, which is good!
The conceptEchoLink is used to connect to other computers running EchoLink, one-to-one, be they other amateurs sitting at another computer, or a computer connected via a circuit board to a radio link/repeater which allows anyone within radio range to talk back to you.
On the PC you may do one of three things with EchoLink :
o Call (or answer) another PC EchoLink station
EchoLink is not really designed to allow you to dial up a frequency at another part of the world and just listen in on an existing QSO - it is up to you to announce your presence and join in. As you can see, this isn't exactly ideal for those who are a bit reticent, and it's not surprising that there isn't a 'listen only' version of the program for SWLs.
They know you're there - if you call an on-air link/repeater be aware that you call is read out by a text-to-speech device! You may as well call CQ so that listeners don't wonder what on Earth you're doing. Also be aware that an amateur running such a link or repeater is required by the NOV (Notice of Variation to their licence) to monitor the link whenever it is operational. Potential abusers of the system should bear in mind that EchoLink works by registration and you could be barred (and of course everything you do on the internet is traceable by your IP number, your Internet Service Provider can tell who has/had which IP number at any time, and your contract with your ISP normally binds you to behaving yourself).
Radio users enjoying EchoLink on the air may :
o Answer incoming calls
Such radio users with DTMF can call specific stations by their ID number (more about this in a second) or by entering the right code can choose to be connected to any one active station at random (PC user, another link, or a Conference Room).
EchoLink is based upon an original system called iLINK. "After 6 years of operating using iphone and as a gateway operator since day one, I'm qualified to say that this (iLINK) really is a great program and there's no going backwards to iphone." - Graham G4HFG, 4 August 2001
ID numbers for each nodeEach EchoLink / iLINK station has its own unique number, yours is allocated when you register and remains the same from then on. Not only can PC users of EchoLink call you, but on-air stations can use these numbers to dial you up, with DTMF. Starting at 1001 for the author of the original iLINK software, by Jan 2002 the 7000s were being allocated, with over 90 new users per day, rising to over 100 per day by mid-February. The system was designed to cope with five digits though, with the 10,000 barrier being passed on 2002-feb-12. The number 12345 may be called by DTMF so long as the last digit is dialled within a second or two of the previous; if you wait too long before dialling the fifth digit it'll end up calling the four digit number (1234 in this example). Not much more than a year later, the 100,000 milestone was fast approaching, and reached on 2003-apr-03. The system copes. We've probably got quite some time before we reach 1,000,000!
Computer problems? On routers, open ports 5198-5201 and that should do it. Windows XP has a router built in and may need some settings changed (5198/99 UDP, 5200/01 TCP).
How it came to beEchoLink came about due to iLINK, which first appeared around May 2001. Things were going well for iLINK for at least a year until EchoLink came along and provided an alternative user interface. It used the same protocols, the same servers, totally interoperable with standard iLINK.
In June 2002 though, iLINK's author Graeme made new versions of iLINK incompatible. This was due to the problem that stems from EchoLink's ability to let a conference connect to another repeater (or user) without any intervention on the repeater operator, whereas Ilink does not. "it impacted the way in which the existing system operated. I was one of those that complained in the way the echolink conferencing worked and the potential impact it would have on linked repeaters. The steps Graeme has taken might seem drastic but were required as no corrective measures appear to have been taken from the other end." - Paul G4HLF.
Says Graeme : "I am trying to link servers, and have given K1RFD permission to have the ILINK user database, for his own server system, and trying to keep both clients interoerable, but by option."
For one reason or another, EchoLink has all but totally replaced iLINK.
(It had appeared that it was going to be called HamLink - see www.hamlink.net - although for a while in 2002 there was another hamlink site www.hamlink.com trying to promote yet another piece of software! This has now vanished and can only be seen via www.waybackmachine.org - I wonder what happened to it?)
The section about iLINK has been cut out to a separate page. If you'd like to see how EchoLink began, click here.
IRLP Internet Radio Linking ProjectHomepage : http://www.irlp.net
UK News : http://www.qsl.net/g3zhi/ukirlpnews.htm
Running since November of 1997, this mainly USA system is designed for linking repeaters together, and not for computer-bound users. In an attempt to keep clueless would-be abusers away, it doesn't run on Windows but the far more 'difficult' Linux Open Source operating system (while making it as easy as possible to install on that - go figure!)
"While you can listen to IRLP via your PC, by design there is NO access to IRLP via a PC. The only access is via a Real Radio!"
There is a way to listen in, which requires a small Live365 player plug-in.
Hear IRLP Live at
"There are two connection modes for an IRLP connection. Direct one-to-one or, one-to-many via a Reflector."
Color coded IRLP nodes status page : http://wa2dci.com/status.php
You may encounter various opinions about secretive aspects, Linux zealots, club membership requirements etc., from what I've heard. "Do not mention IRLP codes when talking to other amateurs via the IRLP system... If someone asks you for information regarding their local IRLP system, please tell them to find the local repeater owner, operator or club to get further information."
For the truth according to IRLPer VK2YX, read http://fudbuster.vk.irlp.net
Despite my admiration for Linux, I remain indifferent about IRLP, it has nothing to offer me
without a web client or a local node to access.
I can only imagine enthusiasm for
IRLP amongst the operators of the nodes, and those fortunate to live within range of them.
The early voice-link experiments were carried out with I-Phone, using VOX (Voice Operated changeover)
which isn't ideal but can work well enough. There are numerous Internet Phone products available,
designed for non-amateurs to talk from one PC to another, and these can obviously be used in the same way
but none are as popular as the systems mentioned above in this application.
EchoLink can support DTMF decoding in software, but an external card can reduce load on the PC.
Also, some cards have 2 audio inputs on them, allowing additional control over another radio link.
One important advantage of using an external card is that you can have control over timeouts.
It is not unknown for Windows to crash and if this happens while your radio is keyed it will stay
keyed until you notice that the PC has died. Not good! The card can protect your radio by unkeying it.
The Vocaltec.com company site is still active, working on other products, but the company no longer runs
the servers needed for
conferences, and the http://oraweb.vocaltec.com site URL (for downloads) no longer works.
November 2000 repeater news :
"... initial enthusiasm has waned because of the withdrawal of the popular iPhone software product.
This is still available as a time limited 'trial' from various sources but the original company, which
is no longer marketing the product, is issuing no further licenses. Pirate patches to get round the
licensing are supposedly available but it would be a foolish amateur to use such a cheat."
RptrLink was written by Mark Brown N9YNQ, but according to an old version of the above webpage,
"Numerous complaints in regards the products and support have forced
the removal of all versions of the products, web site, and servers."
More info : http://home.tampabay.rr.com/k4lk/internetlink.htm
Despite my admiration for Linux, I remain indifferent about IRLP, it has nothing to offer me without a web client or a local node to access. I can only imagine enthusiasm for IRLP amongst the operators of the nodes, and those fortunate to live within range of them.
The early voice-link experiments were carried out with I-Phone, using VOX (Voice Operated changeover) which isn't ideal but can work well enough. There are numerous Internet Phone products available, designed for non-amateurs to talk from one PC to another, and these can obviously be used in the same way but none are as popular as the systems mentioned above in this application.
EchoLink can support DTMF decoding in software, but an external card can reduce load on the PC. Also, some cards have 2 audio inputs on them, allowing additional control over another radio link. One important advantage of using an external card is that you can have control over timeouts. It is not unknown for Windows to crash and if this happens while your radio is keyed it will stay keyed until you notice that the PC has died. Not good! The card can protect your radio by unkeying it.
The Vocaltec.com company site is still active, working on other products, but the company no longer runs the servers needed for conferences, and the http://oraweb.vocaltec.com site URL (for downloads) no longer works.
November 2000 repeater news : "... initial enthusiasm has waned because of the withdrawal of the popular iPhone software product. This is still available as a time limited 'trial' from various sources but the original company, which is no longer marketing the product, is issuing no further licenses. Pirate patches to get round the licensing are supposedly available but it would be a foolish amateur to use such a cheat."
RptrLink was written by Mark Brown N9YNQ, but according to an old version of the above webpage, "Numerous complaints in regards the products and support have forced the removal of all versions of the products, web site, and servers."
More info : http://home.tampabay.rr.com/k4lk/internetlink.htm
(Click for larger pic)
This system is marketed at gamers. I don't know how well it applies for amateur radio use, but it doesn't seem to be a popular choice so far for links. Some experimental use in the UK was abandoned due to too many technical problems. As yet I've only found the http://www.k4jpe.com/rptraccess.htm webpage about running this with a repeater.
PalTalkCompany : http://www.paltalk.com
(Click for larger pic)
I believe this was once fairly popular for amateurs, but such linking use is now in decline. Instructions in Spanish (!) with pictures : http://www.geocities.com/ea4ct/ea4ct/repetidores.htm
iVisitCompany : http://www.ivisit.info
'Lite' version is a free download. Select special interest : ham radio
Setting up your micFirst of all, let's check you can be heard, provided your sound card is installed properly of course (it should be). If your PC came with a microphone, make sure it's plugged into the sound card - these often feature a row of several 3.5mm jack sockets with different colour surrounds. The mic socket is usually the red one. Now the important bit is to check the sound settings otherwise you'll not be heard.
Let's set your listening levels first, for your speakers or headphones. Down the bottom of the Windows screen in the 'task bar', near the clock, there should be a small icon representing a speaker (if not, you may have to go looking through your start menu - try Programs.. Accessories.. Entertainment.. Volume Control) . Double click this icon and up comes a mixing console showing the settings for various sound sources, with the title 'Volume Control' or perhaps 'Play Control'. The WAV device converts numbers stored in the computer memory into a voltage via a Digital-to-Analogue converter - this is used by EchoLink/eQSO etc., and for playing WAV and MP3 files by outputing thousands of voltages per second to reconstruct a previously 'sampled' waveform. The MIDI device (or 'Synth') is a chip that generates music itself, usually quite cheesy sounding. 'CD audio' is quite obvious, as is Line In, etc.
Find a WAV file or an AVI or MP3 and play it - adjust the volume to your preference for your speakers or headphones. Note that you can adjust the volume you hear by other changing the overall 'Volume Control' channel or the individual audio channels such as Wave device, Synth, CD audio, Line In etc.
What you need to achieve is each audio channel being at least halfway up, preferably all the way up, and use the main overall volume slider to control the actual volume. This optimises the signal-to-noise ratio. You don't want a channel too loud (distortion) with the main volume low to compensate, and you equally don't want a channel too quiet with the main volume cranked up and bring up the background noise.
If you're using headphones, you may be able to monitor your own voice as you speak (which is why I started this section by sorting out your playback levels) if your soundcard supports this (it could be a problem). If you can hear yourself clearly once your overall volume is fine with music, without undue noise or distortion, then you should be OK with EchoLink/eQSO etc.
With speakers, you DON'T want your voice coming out of the speakers and causing feedback howls, so in that case mute the mic channel on the PLAYBACK 'Play/Volume Control' mixer.
Now let's ensure that the microphone is the device that is used to record - while a PC can mix various sound sources for listening, for recording only one device at a time can be selected. If your setting is currently for the Line In socket you will not be heard with EchoLink!
To set the recording input to the mic, select Options from the Volume Contol mixer window, and then Properties - it should all be obvious from here - the 'Adjust volume for' section controls which mixer panel you see, the 'Volume Control', 'Recording Control', or perhaps another. Note that the tick boxes underneath each fader in the Volume Control mute the channel, whereas in the Recording Control they are used to select just one channel at a time. If a channel, such as the mic, has an 'advanced' button, it's worth pressing it to see what other settings can be fiddled with - you don't have to change anything, but you may find you have a 'Microphone Boost' button which gives you 20dB more gain on the mic if it's too quiet even at full whack.
NOTE Some soundcards do not respond to the Windows Volume/Play Control sound settings, and come with their own software for configuration. The popular SB-Live! for example, from Creative Labs, needs to be configured with 'Surround Mixer' from the Start Menu. This kind of advanced soundcard will allow special effects such as pitch shifting and echos which could be amusing to emulate CB for a moment, but should NOT be used on the air! (licence conditions AND common sense, LOL)
To test that everything is working, if you have recording software try recording and check that as you speak the signal level display (like a tape deck's 'VU' meters) lights up most of the display most of the time, almost but not quite reaching the top (which would 'clip' over the maximum level of 0dB). The waveform display at the top of the standby window shows audio levels in a rudimentary way. If you've not got recording software, Microsoft's NetMeeting contains a level meter of sorts. NetMeeting (a free download) is like EchoLink for non-amateurs, enabling chat (and video, with cameras) between PC users online - this might be a good way to play with this sort of technology before trying amateur radio links, but beware that talking to complete strangers without the amateur radio protocols may be a little strange, and you don't share the common interest in radio!
LEVELS : Your speech into the mic is converted by an Analogue-to-Digital converter which can only take a certain maximum volume. Each 'sample' of the current voltage (thousands of samples per second are needed) converts to a number represented by 16 bits. If you speak too loudly your speech will be clipped - it'll run out of number range - the top and bottom of the waveform will exceed the maximum level known as 0dB. Levels are usually defined in dB less than 0dB, e.g. -3dB, a quieter -6dB, -20dB etc. The following table gives values for 8 bit recording for what it's worth, for 16 bits audio just imagine 8 more bits to the right which shifts the values along by 8 bits which is the same as multiplying each value by 256 (i.e. 16 bit audio range is from -32768 to +32767 or as unsigned values 0 to 65535 with silence at 32768). Each extra bit used means that twice the voltage range can be represented, in power terms (voltage squared) this means an extra 6dB, so the total range in theory of 16 bit audio is 96dB. The smallest change in loudness detectable by most people is 1dB, and a perceived doubling of loudness requires a 10dB increase.
You want your speech waveform to use the whole of the dynamic range possible while only just approaching 0dB on peaks (an occasional clipped peak doesn't sound too bad, EchoLink especially seems to handle it quite gracefully). So, not too quiet or we can't hear you, and not too loud or you'll sound like a fuzz box :o)
If you think your mic isn't doing your voice justice, you may find that the best results can be obtained with a good musician's / broadcaster's mic. You may need to plug this into a preamp or mixer (even a disco mixer will work nicely) and then select the Line In to record with, now that you're using the Line In instead. If you're not using the mic socket, turn it off from playback (mute the channel in the Volume Control) and you'll get less hiss in your headphones - mic inputs are usually quite noisy.
Good quality dynamic mics can sound very nice, but I've always found electret 'condenser' mics to have a superior quality - better treble, cleaner/smoother more detailed sound, less 'colouration' or boominess, and higher output with better corresponding S/N improvement (generally 10 to 20 dB more sensitve, so less of the hiss noise in the mic preamp will be noticeable). Dynamic mics simply do not repsond to the more rapid changes of air pressure in the treble region due to the construction of the transducer, this is of more note for hi-fi recording rather than communications use but you may well also find that the 'warmth' attributed to dynamic mics is a boost in the bass region that really doesn't suit some male voices and detracts from readability. Effective communications requires good clear audio above 250Hz and indeed this bass region is filtered out when CTCSS is used on FM - for SSB you really don't want most of your ERP being in the wrong region of the audio spectrum!
Electret mics do need to be powered however (i.e. by a battery which usually lasts for absolutely ages), but you may find, as I have, that with a little bit of luck (avoiding *really* dirt cheap rubbish) you can achieve quite an impressively clear sound for a quarter the cost (or less!) of a 'pro' quality dynamic mic. I recently found my favourite mic is still available from a Dutch company (thank-you Internet!) for under 20 quid - compare that with the 100 notes you could happily part with in exchange for a nice Shure. No, I'm not telling you what model it is until I've bought a few spares :o) and even then I'm not telling in case some sound-quality snob disagrees with me, LOL, but I will say that I once bought a Vivanco tie-mic (powered by a button cell) that sounded almost as good. Maybe it's what suits my voice - your mileage may vary, as they say.
Is it REALLY Amateur Radio?
My viewsOf course it is! Well, yes and no, to be honest. Between two computer stations it really isn't anything more than Internet Phone using Amateur procedures, and I have to admit that aspect doesn't really interest me a great deal more than NetMeeting ever did (and I played with video cameras with that, which was more exciting but I still found the novelty wore off after two or three sessions).
If the QSO itself is all that matters to you, then yes it is much the same as what you get from amateur radio, but for some reason I seem to need Radio to be involved somewhere. Still, if purely internet operation is something you enjoy then go ahead and enjoy it because it certainly doesn't affect anyone else.
Once RF is in the equation, i.e. I know I'm being heard on a link/repeater, then I'm interested! I defy anyone to tell me it's not real Amateur Radio (I'm sure some will). It certainly is REAL radio for the other station, and I'm happy to be giving them a chance to work someone in this unusual and interesting way. It is one amateur communicating with another via radio! I perceive such operation as being little different to working through a repeater with my radio instead of my computer, because it is the incoming signal into the repeater that matters once you have a good 'connection' to it. We are still using a radio, although by remote control. If you're still not convinced, what if I was to set up my own on-air node and sit next to the computer using a low-power handheld?! Would *that* suddenly make all the difference? What amuses me is that not only has the internet made most people realise how the Morse requirement is a pointless obstacle to international communications, but the same internet has also brought us a rather neat way around it :o) No wonder it has upset some of the miserable old 'do it my way!' minority. It's a great leveller, too - how are the show-offs going to upstage the rest of us? They may have the tallest tower, the biggest linear amplifier, the most expensive radio but what are they going to do with the computer, buy the biggest microphone? :o))
For radio operators using links to other such links around the globe, where both operators are using radios, that is pure Amateur Radio at its innovative best. A similar thing could be achieved with satellites and nobody would bat an eyelid, so it baffles me why anyone would dismiss this as not 'real' amateur radio. You can take advantage of the atmosphere to bounce a signal around the world, and we'll take advantage of an internet link - one is natural the other is due to technical advances that are entirely in the Amateur spirit. Just think of the internet as a nice big waveguide, HI.
Something similar (in effect) to Internet Linking could be achieved with a constellation of satellites, although obviously at massive expense! Imagine a number of 'birds' up there enabling global coverage on several 70cms channels with normal handhelds, with DTMF control of links between the satellites themselves. Would the IARU/ITU object to this? Then why should any national government department prevent Internet Linking with 'unattended' equipment - the equipment on board a satellite is unattended after all!
There are simple and reliable ways to provide for remote shutdown of an 'unattended' link or repeater, so I believe the RA should not confuse 'unattended' with 'unmonitored'. Internet access is an annoying expense, so it would be of great benefit if a group of amateurs could pool their resources, and form a club to run a simplex gateway or linked repeater. Just one slight relaxation of the current rules would allow a club to run a transmitter from a good location, while the members share the expenses. Remote shutdown can be achieved in a variety of ways, via DTMF (on another frequency even), via the internet, even by SMS messaging etc. I think 'unattended' operation is what we need to push for next, even if monitoring is still a requirement.
Even if at first, only IRLP is allowed 'unattended' (with no PC users), let's hope we can get a sensible approach to 'unattended' operation. Even if 'unmonitored' is still disallowed, 'unattended' equipment with remote shutdown would be a big improvement. Face it, anyone old enough to intentionally listen to an amateur transmission is aware that something offensive could potentially happen at any moment, but I truly believe in this day and age we should be more open minded and consider that the slight chance of abuse is far outweighed by the enjoyment afforded to the vast majority. Various 'checks and balances' have always ensured that Amateur Radio does not descend into the chaos of CB. Any abuse can be traced to the IP address or particular RF station. If a link operator cannot keep abuse from their system (unlikely), the NOV could be revoked as a last resort to keep clear the system as a whole. No need to punish the rest of us! Abuse can be easily traced, if needs be. In any area there are numbers of amateurs keeping an eye on what's happening on the bands, and plenty who enjoy the challenge of tracking down signals. I believe we can keep the system clear.
So, from what I've seen of how Amateur radio is defined, Internet Linking certainly fits that definition to me, and obviously also to the RSGB and the Radiocommunications Agency (and their equivilants around the globe), otherwise it wouldn't be happening. Also bear in mind the Amateur tradition of spreading 'international goodwill' and I consider the case quite sound. I find it difficult to accept the view that linking 'clogs up' repeaters, coming from an area where the repeaters are little more than sporadic beacons! iLINK allows links to be turned off for local traffic, problem solved. More activity is always a good thing in my view, more to listen to, more opportunities to attract new blood into the hobby. It is all between licenced amateurs doing what they are licenced to do. If neither party using iLINK is 'on the air' then nobody can rightfully complain, and so long as one party is using a radio, it IS Amateur Radio. So long as the system isn't abused by computer users, there's nothing to fear, although I can see that this is a real concern. I suspect that isolated problems may occur but I also expect that we will find solutions. This is truly 'moving with the times' and updating the hobby for the better. What a great way to raise the profile of the hobby in the minds of the public. My thanks to everyone involved! Long live Internet Linking!
And now for a paragraph written (Summer 2002) a couple of months later than the above. I guess it *isn't* sufficiently like radio for me, because I've lost a lot of interest already. Part of that is my reluctance to spend a penny per minute for internet access (tight, huh?) or have the phone line tied up for ages. If I had 'always-on' broadband (which would need to be well priced, LOL) then I'd use it more. For now though, I'll just keep an eye on how things are going, with the occasional eQSO perhaps. iLINK would be better with a do-not-disturb option, so that I could only call out. However, all the decent new features are only in the paid-for "Pro" version!
If I may present a personal opinion.. bearing in mind years of frustration with Windows, and great admiration for Open Source software such as Linux. Linus T. has earned huge amounts of respect for creating something FREE (Linux), and delegating aspects of its control to other people because it's all too much for one person. I believe Graeme had the chance to do the same thing with iLINK but may lose out to a more open system if he keeps iLINK proprietary. I can see his reasons for trying to separate iLINK and EchoLink and his disgust with many people's ingratitude but I think he may well lose out in the long run. Amateur Radio needs Open Standards. If I had been talented enough to create a useful piece of software I would have made it as free as possible and would have been happy with just the personal 'glory'. It it had become too much to handle, I would have been delighted to delegate and remain an integral part of a much larger movement, working with other people on a Free system. I can forsee IRLP remaining dominant with Repeater-Repeater linking, eQSO filling the niche for decentralised conferencing, and Many Other Contenders evolving alongside iLINK (to bring Repeater-Repeater linking to the Windows platform with additional PC access and conferencing). I do applaud Graeme's achievement with iLINK, but it just seems to be getting unscaleable. See the ILINK-GEN mailing list for a lot of ill-feeling on both sides of the argument (June 7, 2002)! I still don't feel at ease with paying for the 'PRO' version that has more features - it doesn't seem to be the spirit of Amateur Radio - just my opinion of course. Fair play to anyone who tries to make money from their talents but as a renowned cheapskate I'll always take the free option when there is one! However, I do have my doubts that there are sufficient Open Source programmers to create a free contender, so we'll be limited to one-man efforts regardless :o)
Basically, I'm more at ease if my software will continue to run even if the unthinkable happens to its author, rather than relying on their server. The latest information I have read suggests that Graeme is happy to work with Jonathon (EchoLink) to make the two systems work together again. Sounds good.
Well it's been interesting to explore this latest aspect of the hobby. I've had this page featured on the ARRL site, and had 250 hits per day at one point. I've had a go at improving the WAV files included with iLINK, sent them back to Graeme and now they are included with current versions. But now that's probably it for a while. Even if remote sites are soon permitted, I doubt if anyone else over here will be sufficiently interested. Plus, I can now operate on HF if I want!
And now an update, Spring 2003. iLINK has all but disappeared, as I thought it would, while EchoLink goes from strength to strength.
That'll do for the Opinion Zone, now back to the facts.
Packet Loss?Yes, it happens. Internet congestion can cause the packets of data containing speech to get garbled, or arrive out of synch and be ignored, leading to breaks in the audio. You may have heard the term TCP/IP in connection with how the internet works - IP is the Internet Protocol to standardise how data flows around the network. IP can transport TCP and UDP (UDP/IP) data :
TCP (Transmission/Transfer Control Protocol) is connection oriented, with more flow control and error checking sophistication. A two-way connection is established, each package receipt is acknowledged, and the connection closed when finished. Useful for obtaining an entire webpage, for example.
UDP (User Datagram Protocol) on the other hand (as used for 'streaming audio') is connectionless, faster than TCP, but not as reliable - depending on the application to check such matters. A one-way datagram is sent without notification of sending or receipt. The receiving software simply uses every 'packet' that it can in order.
For perfect reception, a 'fat pipe' is what you need - a high bandwidth connection. This assumes that every other part of the path from the source is also not stretched to capacity, so your ISP is important too. I usually have few problems with EchoLink on an ordinary dial-up modem, even with paths around the planet to Australia. The odd break here and there doesn't really spoil things too much, no more than fading or interference on the air. Maybe instead of muting the audio such breaks could be replaced by bursts of a RTTY effect for more realism, hehe.
"IRLP uses 32kbps plus UDP overhead (probably around 35-38 kbps total). EchoLink uses around 16kbps. Someone mentioned they found GSM 6.10 in the voice data packets, which uses around 13kbps, so 16kbps is a reasonable estimate of total bandwidth per connected user. Echolink usage will be same as EchoLink."
How popular do you expect to be if you call a repeater when it's 3am in their local time?! If you keep 'normal hours' (you don't work nights), the general rule for two largest English speaking areas of the world could be as follows... work Austalia/NZ before our lunch (their late evening) or late at night (their morning), and work USA/Canada any time after our lunch (when they rise).
If you're reading this *FROM* those far-flung places, we Britons are getting our beauty sleep during the Australian working hours, and in the American afternoon until the middle of the American night (you'll work us in the early evening if we stay up late, more especially in your east).
Your own gateway? (very optional!)If you enjoy internet gateways so much that you want to provide a facility for your own area, it's actually quite simple to set up your own on-air link. There will need to be a spare frequency in your area that can be approved for your use. You need to monitor all use, so that you can disconnect any abuse, but you don't have to keep the station on-air all day and night! You will need to apply for an NOV for your licence (UK), and to interface to your radio you'll need a slightly different piece of software and possibly a small external circuit board. All the help you may need will almost certainly be forthcoming from the various mailing lists. If your station covers the local area well and you are happy to be connected to the internet while keeping an ear on the proceedings, please proceed, and thanks very much!
Linking URLsUK Gov.'s Radiocommunications Agency http://www.radio.gov.uk/topics/amateur/document/linking.htm. (Amateur index)
Mailing list group for general *Amateur* voice-over-IP :
"Who's on" query - all systems : Internet Radio Linking Database : http://www.andersoft.com/elink
eQSO (M0ZPD) links
Homepage : http://www.eqso.net (ex http://www.qsl.net/m0zpd)
Who's on : http://www.eqso.info/whoison.html
Email/Web Forum http://groups.yahoo.com/group/eqso
EchoLink linksEchoLink homepage http://www.synergenics.com/el/ (or http://www.k1rfd.com )
Who's on : http://www.echolink.org/logins.asp
or http://home.insightbb.com/~n9yty (with masterlists)
or http://wa2dci.com/echo_status.php (can order by node)
Nodes Map : http://www.echolinkmap.org
Email/Web Forum http://groups.yahoo.com/group/echolink
and clarified the situation in the Word doc http://www.radio.gov.uk/topics/amateur/document/op-procedures.doc (example NOV)
If you've come staight to this page from a 'search engine' or other site, please continue to the homepage for more about GJ7JHF, my email address etc - click the link below.
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(c) 2002-2003, Andy GJ7JHF, not that I care, for this page, just give me credit if you use anything!
I wrote most of this within a week of first loading iLINK, which shows how much I was inspired,
but is also my excuse if I'm wrong about anything :o)