July 2002

Amateur Radio Internet Radio Linking

Ian Abel G3ZHI

[email protected]



It is now common for those on the Internet to communicate with friends and family around the world using voice and video, which requires their computer to have a camera, microphone and soundcard fitted.

For radio hams the next step was to link their FM VHF or UHF transceiver to the computer sound card enabling audio from their transceiver onto the Internet. If a similar link was taking place on a remote computer and both computers were linked together via the Internet (in the UK or anywhere in the world) you could have a radio to radio QSO with the Internet providing the link in the middle.

The transceiver could be operating on either a local VHF or UHF repeater, or an FM simplex channel. All Internet linking on repeaters takes place in the shack of the ham providing the link, nothing is done at the repeater site. The audio quality is normally excellent. DX stations sound just like locals.

With the more liberal ham radio laws in the USA and Canada, Internet repeater linking has been in use there for more than 6 years. The first program used was Vocaltecs’ IPHONE but any program that allows audio over the Internet e.g. MSN Messenger or Paltak can be used for linking and provide basic radio communication.

This would be done by holding the transceivers’ microphone to the computer speaker and transmitting the audio off the Internet over the air, then holding the computer microphone to the transceivers’ speaker and transmitting the audio over the Internet.

The TX/RX change over would be made by manually pressing the PTT but with more sophisticated programs like IRLP the TX/RX change over is done automatically using an interface board and the transceivers ‘COS’ (carrier operated switch) data line, allowing repeaters to be connected to the Internet 24 x 7.

In the UK permission had to be obtained to link Ham radio to the Internet from the Radiocommunications Agency and a personal request was made by Ian Abel G3ZHI to David Hendon G8DPQ their Chief Executive at RA Road Show in Leeds October 1999. David Hendon gave his permission in January 2000.

There are currently four Internet linking systems in use IPHONE iLINK eQSO and IRLP. The first three run under Windows 95 and above and each program can be downloaded from my web site. IRLP runs under Linux Redhat 6.2 (this version only). For those not familiar with Linux the UKIRLP Group are willing to help with installing Linux and the IRLP software. Using Linux is straightforward when the Graphical User Interface (GNOME) is also installed , as the Desktop looks similar to the Windows Desktop.


As of April 2002 185 NoV’s have been issued for simplex Internet gateways.


111 70cm

1 70cm 7.6mhz split repeater

Getting connected.

If you wish to install an Internet gateway you first need to apply to the RA for a Notice of Variation (NoV) to your Amateur Radio Licence. For a simplex link the application can be made on line on the RSGB DCC web site. The site lists all the 2m and 70cm frequencies available.

If you wish to put the link on a repeater you must first obtain the permission (in writing) of the keeper and then send a written application to the RSGB RMC Chairman Carlos Eavis G0AKI QTHR supplying all the information required for a simplex link, plus the callsign of the repeater you wish to put the link on , a copy of your licence validation document and the written permission of the keeper.

You could install your own 70cm 7.6 Mhz split repeater and install an Internet link on it. 7.6 Mhz repeaters are ‘fast track’ repeaters, as the application is processed quicker than a normal repeater application.

Some software changes will probably have to be made to the repeater logic as no repeater identification must be sent over the Internet, as it causes problems with the other repeaters that are connected producing a ‘ping- pong’ effect (repeaters continuously keying each other on and off). The logic must also be capable of operating CTCSS.


As Internet linking is worldwide, hams in many different time zones help to police the links 24 x 7 and any problems are reported to the stations providing the links.


Using an Internet link DX stations can be worked from home, while out walking, or bicycling using a hand-held. A typical example is to have a roundtable QSO with hams on repeaters in the U.S.A, Canada, South Africa, The Caribbean and Australia all in the same QSO.

Some American repeaters transmit simultaneously on multiple frequencies e.g. 2m 6m 10m 220mhz and 70cm so you can be transmitting on many different frequencies all at the same time.

The most remote place on IRLP is the American Mc Murdo Base in Antarctica. The base has a ‘live cam’ , http://live7.truelook.com/nasa/mcmurdo/index.jsp camera, which you can control, the picture quality is very good. For 6 months of the year the base is in 24-hour daylight so with a little organisation it would be possible to see the person you are talking to, if they stood in front of the camera. I have done this here from Sheffield and stood in front of one of the ‘live cams’ cameras on Sheffield University, while talking to hams on IRLP who were able to see me.

Some overseas repeater linked systems are very sophisticated with many repeaters linked together by RF. In New Zealand for instance they have the 70cm National System that has 19 repeaters linked together, providing nearly full coverage of both the North and South Islands. In 2001 when Tony Whitaker G3RKL was walking the length of the country (top to bottom 1,300 miles) I was able to keep in touch with him daily, while he was on his walk and patch him through to his local repeater GB3US in Sheffield (Tony is the keeper) to talk to his friends.

In the U.S.A. and Canada there are a number of linked systems. One example is the Winsystem in California which links San Diego to San Francisco via 17 mountain top repeaters (some over 8.000 Feet high) all linked together.

Another repeater with excellent coverage is the Tram repeater in Palm Springs California , so called because the Tram goes to the top of the mountain where the repeater is. Also on the top of the mountain there is a ‘live cam’ which is next to the repeater site, which you can view from the Tram web site http://www.pstramway.com/ and enjoy the beautiful scenery and see the repeater coverage.

In the future maybe all repeaters in the world will be linked to the Internet enabling hams to keep in touch with ham friends visiting any city in the world that has a repeater.

Internet linking is ideal for long QSO's making it possible to have in-depth discussions unaffected by QRM or QSB.

G3ZHI has given a number of talks to radio clubs in the U.K. and around the world using Internet radio linking it could be used by any ham to give a club talk on any subject.

Contacts can be ‘one to one’ or in a ‘round table’ where many repeaters are linked together. Sometimes on IRLP 30 repeaters can be linked and all the users on each repeater are able to hear each other.

For elderly hams that are no longer able to look after their aerials and towers, or hams that go into retirement homes, this is an excellent way for them to keep in touch with ham friends. I recently worked one ham in the USA who was 92 and using a handheld from a retirement home. Some retirement homes will permit computers and handheld radios but not a HF radio plus aerials.

While you are at work, university, school or at an Internet café, providing the computer you are using has a microphone and soundcard you can talk or just listen to your ham friends without having access to a radio.

Internet linking will work on a 56k-dialup modem but a high-speed connection is best.

Repeaters represent a big investment in both time and money and the aim of the Internet radio-linking project is to increase activity on repeaters and simplex channels.

Using IPHONE 4.5 one of the memorable QSO’s G3ZHI had was with the Motorola Museum club station in Chicago USA K9MOT. While talking to K9MOT over the N9EP-R repeater, a radio amateur passenger in a light aircraft joined the QSO, working aeronautical mobile (which is permitted in the USA). Just at that time the aircraft was flying above the Museum and the radio amateur in the plane was sending live video to the club, they then forwarded it via the IPHONE program, so G3ZHI was able to see the video from the plane.

G3ZHI has also worked another radio amateur passenger in a light aircraft, this time while out cycling and using a hand-held on GB3DV, the 70cm repeater in Maltby, which was connected to N9EP-R in Chicago via IRLP.

He has also made contacts world wide while out bicycling using slowscan television.

Colour pictures have been sent and received using a Kenwood VCH1 on a 2m simplex channel connected to an internet link.

When Mark Shuttleworth the millionaire astronaut was aboard International Space Station, although not a ham, he was granted the special callsign ZHAM. This allowed him to make use of the ham radio station aboard the ISS and use it to make contacts with schools in his native South Africa. These contacts were also relayed on repeaters around the world via IRLP. It was very nice to sit in the shack and listen to the ISS on the local repeater GB3DV.

Perhaps in the future a U.K. repeater system could be developed providing full coverage of each Motorway . e.g. The M1 motorway could have several repeaters all linked together providing continuous coverage from London to Leeds.

Check http://www.dcc.rsgb.org/ShowGates.asp?call=ALL to see if you have a local gateway near you. If you live within 10 miles of a gateway you should be able to hear it when it is active. They are not all 24 x 7 and you may need to contact the keeper to check when the link is available.

You can listen on line to the Californian Winsystem 24 hours a day by following the link on their web site at http://www.winsystem.org

There are a number of ‘egroups’ on http://groups.yahoo.com which have discussions about Internet linking which you can join.

For sites on repeater Internet linking search using http://www.google.com

To use the Internet linking programs on a computer it must have a microphone, soundcard and speakers fitted. It is a good idea to first test that your microphone and soundcard are working correctly by using the sound recorder program located in Windows Accessories.

IPHONE (5mb download)

IPHONE has been used for ham radio linking since about 1996 and offers audio and video.

The iPHONE servers are no longer available.

In order to use the program you need to know the i.p number of the person you wish to contact. To obtain your i.p. type winipcfg at the dos prompt and the program will show what your i.p is. If you are on a ‘dial up’ connection this number will change each time you connect, if you are a permanent connect the number will remain unchanged.

When the iPHONE servers were running you joined the ‘ham radio’ private chat room. This was done by first clicking on the drop down menu ‘Chat Room’ on the ‘Global On Line Directory’ then click on ‘New/Private’ type in ‘ham radio’ - all lower case then click ‘join’. You would then see a list of all the ham stations in the room. Click on a callsign to call the station, which could either be an individual, who is using a computer, a repeater, or a simplex link. Non-hams can also use the program enabling SWL’s to talk to hams, this is fine provided there is no radio link involved.

It might be in future someone else provides an iPHONE server which could be used.

Linking your transceiver to the Internet with the IPHONE program by using a VOX unit to operate the TX/RX function. Ready built VOX units are available from CPC http://www.cpc.co.uk part number HK00035 priced £16 pounds.

Vocaltec no longer sell the IPHONE program and there they will not allow you to register it. However it can be uninstalled and reinstalled, as many times as you wish (it only takes a couple of minutes) on 7-day free trial basis.

IPHONE also has a ‘white board’ facility that allows you to exchange text, photos and diagrams with the person you are talking to.

Unfortunately, if you are on a hand held which is connected to the Internet via iphone, you have no way of knowing who has joined or left the room. Therefore you are not able to call stations , you must rely on hams that join the room, who are using their computer and can see the list, calling you. When hams click on your callsign and calls on your link their audio triggers your VOX unit and puts your transceiver into transmit, when they stop transmitting your transceiver returns to receive and the transceivers audio is passed straight on to Internet. So when you transmit they hear your audio.

IPHONE used to support conference rooms but the facility is no longer available.

IPHONE provides little security so links need to be monitored when the program is being used.

iLINK (300k download) http://www.aacnet.net/

Developed by Graham Barnes M0CSH in 2001.

There are two iLINK program downloads one is for a PC user and the other is for someone providing a gateway and the iLINK interface board.

iLINK users can chat computer to computer, computer to radio, or radio to radio..

Before you can connect to iLINK you have to apply to the administrator for authorisation. To obtain this you have to provide a callsign and a password of your choice. Once your details are verified authorisation is granted but it can be removed at anytime, if there was a need to do so and you would be unable to connect to the server.

If you wish to link your computer to your radio you require an iLINK interface board which costs £25. Around 10,000 hams around the world have so far download the iLINK program. There can be between 100 to 300 users on the iLINK list at any one time.

After installation when you run the program you are presented with a box. Click on BEGIN and a list of stations will appear. You can then call any station on the list or a station could call you. The station you call could be a ham sat at his or her computer using a headset, a repeater or a simplex radio link. There are also several different conference rooms and all stations in the room are able to hear each other.

When you have finished your QSO ‘click’ on ‘END’ which disconnects.

There is no SWL listen facility, you must be a licensed ham to download and use the program.

Each station is given a unique number and using DTMF on a radio you can call an individual station. However, when you are mobile and not able to see the list of stations connected on a computer screen, you do not know who is on line as stations come and go at random although some are on line 24 x7. You have to use your experience to gauge which stations are likely to be on line at any particular time.

You can dial ‘00’ that will connect randomly to any station that is on line at that time or ‘02’ connects you to any free conference server. ‘#’ disconnects. ‘0’ checks the on air node status.

For those using computers there is also a text chat facility which is very useful if you are having audio problems or don’t have a microphone.

The audio quality is very good and the servers are very reliable.

To transmit you press the space bar once and then press it again to listen.

There is an ‘info text’ file, which you can edit, when someone connects to you the information is displayed on his or her computer.


eCHOLINK http://www.synergenics.com/el/

This is a new windows front end to the iLINK program.

The program has been written by K1RFD offers many user friendly features and works with the iLINK board.

eQSO (400k download) http://www.eqso.net/

Developed by M0ZPD in 2001.

The eQSO program can be downloaded from the above web site and installation is straightforward.

When you join a server everyone in the room you select can all hear each other. You can change servers or change rooms on that server.

You can view the full list of all servers and rooms and who is in them.

eQSO can be installed on any computer, including a laptop, anywhere in the world, to have a QSO’s with fellow hams.

SWL stations are welcome to listen and should identify that they are SWL’s. They must not speak unless they are in an SWL only room, which is off air and has no radio attached.

There are three levels of security in place and people can be ‘kicked’ ‘banned’ or ‘muted’ by controlling stations that are monitoring 24x7.

Hams over the world are using eQSO and some are in very remote areas, part of the fun is you never know who you will find on the system. Recently hams in China have started to use the program and I have worked quite a number of them. One Chinese ham has just installed the first RF 70cm Internet gateway in China.



Internet Radio Linking Project http://www.irlp.net

Developed by Dave Cameron VE7LTD in 1977.


IRLP is primarily a worldwide Internet linked repeater network with over 500 repeaters connected together 24x7. The number grows almost daily.

It is a totally secure system running under Linux Redhat 6.2 (not later versions) and you cannot speak on the IRLP system from a computer, which is connected, to the Internet, like you can using the Windows programs. IRLP was designed just to link repeaters around the world although there are a few links that are on simplex channels.

You call a repeater by using DTMF tones and there is a directory list of all repeaters giving their individual 3-digit number. You use the number to connect and disconnect from the repeater you wish to call, adding a control digit ‘0’ to turn a link ‘on’ and a ‘1’ to turn a link ‘off’.

e.g. To call VK2RBM in Sydney you would tune your radio to a local Internet linked gateway frequency and then dial 6000 to turn the link ‘on’ and 6001 to turn the link ‘off’. You will hear a voice announcement identifying which repeater you are connected to. When you disconnect you get another voice announcement saying ‘you are now disconnected’ again identifying the repeater you have left.

You can use a ‘touch tone’ DTMF microphone costing about £50 or buy a DTMF keypad costing £2.50 inc. P&P available from UKIRLP.

You can call individual repeaters or connect to a Reflector, this is a ‘conference room’ which can have as many as 30 repeaters in the room. Anyone speaking on any one the repeaters can be heard by all the other repeaters so it is vital that no CW indents or courtesy tones pass from a repeater on to the Internet as it would cause problems.

To connect your repeater to the IRLP network requires an IRLP interface board costing 60 USD plus 15 USD carriage making . To order an IRLP board please visit http://www.irlp.net/


UKRLP (United Kingdom Internet Radio Linking Project) will help anyone unfamiliar with Linux to install the hardware and software.

You can view the ‘live’ status page of all the repeaters on the system by visiting http://status.irlp.net

Dialup connections can be used for IRLP and Linux will automatically reconnect if you are disconnected abruptly or if you get disconnected after every after 2 hours. However, if you are using a dialup connection you are not able to connect to reflectors, so a high-speed connection is the best option.

Some repeaters connected to IRLP are connected to multiple linked systems e.g. the Winsystem in California which has 17 repeaters linked together and the New Zealand National System which has 19.

You can listen to the ‘live’ audio on reflector 2


and on the Winsystem http://www.winsystem.org

For more information on Internet radio linking please contact the UKIRLP group or visit the web site http://www.qsl.net/g3zhi/ukirlp.htm



G3RKL April 2001

G4CUI February 2002

Ham Radio Today

G3ZHI February 2000


Radio Active

G3ZHI January 2000


Useful URLs







Radiocommunications Agency


RSGB Data Communications Committee.


RSGB list of all simplex UK Internet gateways



RSGB Repeater Management Committee


RSGB Guidelines on Internet linking



Yahoo egroups


iLINK links












eQSO simple radio linking interface circuit








Photo graphs

VOX unit

I R L P board

iLINK a board

Diagram of a set up

D T M F keypad

Screen shots





Winsystem map

New Zealand National System map

NoV Application form



UK repeaters with internet repeater linking available

IRLP world-wide repeaters

All UK Internet simplex gateways