Fact Sheet

MB7ITB

The Torbay gateway uses Voice-Over-IP (VOIP) technology to link Amateur Radio stations together via the Internet.

It is one of thousands of such gateways throughout the world. There are currently more than 160,000 registered users in 143 countries.

RF users in the vicinity of Torbay may use the gateway to talk with RF users near other gateways and repeaters, and also to computer-based users.

This Fact Sheet attempts to give prospective users the information they require to get the best out of the system

Location: 4.8Km South/West of Torquay town centre

Locator: IO80fk

Frequency: 145.2875MHz simplex nbfm

Antenna: 5/8 over 5/8 dipole at 30 feet AGL

Polarisation: Vertical

Radiation Pattern: Omni-directional

Effective Radiated Power: 10 watts

Intended Coverage: Torbay

Availability: Approximately 10am till midnight each day.

VOIP Network: Echolink. Node number 257017

Conferencing: Enabled, 6 users max.

Computer: Pentium 1.2 gig running Windows XP Pro

Gateway Software: Echolink

Radio Interface: RigBlaster Plus

Signal detect: VOX, 2 second max. pause

Access Method: No toneburst or CTCSS required

Identification: 12 wpm CW, every 15 minutes

System Operator: Bob G0AZX

Plus Thanks to the rest of the Links committee

Who help with the running of the link :

G3PCT G7HIK G3VOF

Here are some guidelines to the sort of equipment you will need, to get the best out of the Torbay Link:-

DTMF

You can work the gateway using a simple rig, but to get the best out of the system you really need the ability to generate DTMF tones.

Most modern radios have a DTMF keypad, either built into the radio, or on the microphone. DTMF microphones can be purchased to fit older equipment.

Alternatively, inexpensive self-contained DTMF generators are available, which can be held next to the microphone.

12.5KHz Channels

All UK gateways are required to conform to 12.5KHz spec. You will probably get by with a 25KHz radio, but as the number of gateways is increasing, you may experience QRM from gateways and other services on adjacent frequencies, and you will get better results using a proper 12.5KHz radio.

Also, with a 25KHz radio you may over-deviate, causing you to "chop" out of the receiver on speech peaks, so you many need to back off from the microphone or turn the deviation down a little.

CTCSS

CTCSS is not required at present, and there are no plans to make it so.

Tone Burst

Tone bursts are NOT required. The link is always open

RF Power

The gateway is only licenced to run low power, so if you can hear it, you can probably work it. 5 watts should be ample, but use as much power as you feel comfortable with.

If you use too little power, your signal into the gateway might be desensitised or distorted by adjacent or co-channel interference, and other people on frequency may not be able to hear your signal, and may therefore transmit over you.

If you use too much power, you run the risk of interfering with other gateways on the same channel. You can of course minimise this possibility using directional antennas.

Repeater Shift

Repeater shift is NOT required, as the gateway is simplex.

The following table lists the DTMF commands recognised by the gateway.

Please note that DTMF commands are not actioned if they begin more than 10 seconds after the start of your transmission.

DTMF Sequence Effect

* Play ID message (only if the link is not connected to a repeater or computer user)

01 = Connect to random gateway / repeater

02 = Connect to random conference server

03 = Connect to random single user

08 = Find out who is connected

09 = Re-connect to previously connected station.

Is The Gateway Online?

If the gateway is online, you should hear the morse idents every 15 minutes. If you can't wait that long, or you want to check if the gateway is hearing you, make a short *voice* transmission on the gateway frequency, then wait for a couple of seconds. If you hear a "pip", the gateway heard you. Plain carrier alone may not provoke a response, as the system is currently voice, not carrier, operated

If you send the "*" (star) command, the gateway will identify itself and give you some brief information.

Is The Gateway Connected?

You cannot talk to anyone via the gateway unless it is "connected" to them (if they're a computer station), or to a gateway near them (if they're an RF station). To find out who the gateway is currently connected to, use the DTMF sequence "08". The gateway will then speak the callsign(s), or say "Not Connected" if there is no-one connected.

If someone is connected, they will hear your transmissions, and you will hear theirs, so you can have a QSO in the normal way.

Initiating A Connection

a) Connecting to a specific station

just key in their "node number" if you know it.

b) Random Connections

You may wish to do the VOIP equivalent of calling CQ into the ether, to see who will come back, in which case you would use one of the "random connect" commands.

The gateway will randomly select a non-busy node of the specified type, and will attempt to connect to it. It will announce "Connecting to <callsign>".

d) Connection Success or Failure

Sometimes it may take up to 30 seconds to establish a connection, so please be patient.

When the connection is made, the gateway will announce "Connected to <callsign>", and you may then have a QSO in the normal way.

If you don't hear the "Connected" announcement within 30 seconds, it has failed to connect. This could be because the target station has gone off line or busy since the last directory update, or because he is denying access.

If you wish to abort a connection in progress, dial the hash (#) key. This will reset the system, so that it is ready to try another connect.

e) Creating a Conference

You may connect to more than one station at once, to create a multi-way conference or "net". To do this, simply connect to additional stations without disconnecting the previous ones.

Having A QSO

Having a QSO via the gateway is almost the same as having a "real" QSO, with one or two minor differences.

The gateway will send a short tone at the end of each person's over. Please wait for the tone, otherwise you may end up "doubling".

Due to packet losses and random delays in the Internet, the other person's speech may sometimes break up or sound a little garbled. If their over appears to end prematurely, wait for a few seconds before you transmit, because there can be up to 3 seconds of delay before their speech re-commences.

The system is currently VOX controlled, so you should try not to leave silences of more than 2 seconds in your over. If you pause for more than 2 seconds, the gateway might assume you've finished your over, and will send a "pip". It will therefore lose around a second of your speech while the transmitter is on.

Terminating A Connection

After the QSO, either party may disconnect the link. Use the "#" (hash) command to disconnect. If there is more than one station connected, the "#" command will disconnect the most recently connected one. Two hashes ("##") will disconnect all the stations

If you have connected the gateway to a busy repeater, you need to be quick to issue a disconnect command between overs. If there are no gaps, the gateway will time out and disconnect automatically after 4 minutes.

Re-connecting The Previous Station

If a stations calls in and disconnects before you get chance to reply, or your QSO gets disconnected, you may re-connect to that station by issuing the "09" command sequence.

RF Users

It pays to listen awhile before calling on the gateway frequency because there may be someone else, who you cannot hear, using it.

If you haven't heard anything after a couple of minutes, it's likely that no-one else is using it.

Before you issue any "connect" commands, it's a good idea to check the gateway's connection status (by dialling 08), because it may have been left connected by the previous user.

They may have forgotten to disconnect, or driven out of range, or perhaps they were listening for a call. Or there may be someone listening in from the Internet.

If you connect this gateway to another gateway, please give some CQ calls to let people know you are there.

Some gateways announce your callsign to the RF users when you connect and disconnect, some do not. The announcement may be missed the first time, or it may not be very clear.

It is very irritating for gateway users to hear people connecting and disconnecting without ever stating their intentions.

Please mind your language. Your words may be re-broadcasted onto RF, and may therefore be putting someone else's licence(s) at risk.

Internet Users

If you connect to the gateway from the Internet, your callsign may be (but not always) announced on air. Please identify yourself and state your intentions, for example give some CQ calls or say that you only want to listen.

Please don't pester the sysop unnecessarily. If he answered everyone who connects to the gateway, he would never get anything else done :-(

The gateway's VDU is usually turned off, so it is pointless leaving text messages for him.

Remember that your text messages can be seen by other computer users, but not by RF users. If you want everyone to hear that web address you're trying to publish, use speech.

As you have already asked for a copy of this fact sheet for MB7ITB chances are that you are interested in using it. PLEASE FEEL FREE TO DO SO.Remember it is not my frequency it is

MB7ITB allocated by Ofcom for all licensed Amateurs in the Torbay area.And dont forget the old saying to keep it is to use it. So please enjoy the Echolink experience.

73’s and look forward to working you on the link. Bob G0AZX

sysop for MB7ITB