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By LEO SIMPSON Most people will be familiar with Telecom's new cellular phone service which is becoming very popular with business people who spend much of their day in their cars and trucks. Now OTC's automatic Seaphone service is doing for boats what the cellullar phone service has done for cars but at much lower cost. OTC's VHF Seaphone service has been operating since 1976 and has been gradually expanding over the years to the point where even relatively minor coastal population centres now have it. Early this year though, OTC decided to substantially upgrade the service so that people on the waterways and as far away as 68 SILICON CHIP 100km out to sea could have direct phone dialling, ship-to-shore. Local electronics company Heyden-Spike Ltd won the tender to develop the system and has now produced a computerised system which will radically alter communications on the water. The problem of automation OTC (standing for Australia's Overseas Telecommunications Commission] could foresee a large obstacle in introducing an automated Seaphone service: cost to the boat-owners. OTC recognised that if the new Seaphone service was to be really popular the cost of upgrading to it for each boat-owner would have to be low. That meant that all existing VHF marine radios would have to be usable and the cost of any fancy dialling facility would also have to be lower than the cost of a new radio. This meant that the new equipment on the boat would have to be kept relatively simple while all the "intelligence" would have to be installed at OTC radio bases on shore. And that is what has happened. Heyden-Spike Ltd has developed a microphone which, in addition, to the usual press-to-talk switch, has 12 pushbuttons for phone dialling. The microphone can be fitted to any existing VHF marine radio although it cannot be simply plugged in. The radio must first be modified to sup- Thursday Island OTC VHF COVERAGE AREAS VII Chambers Bay Point Quobba Ch Ch Ch Ch Long Point Yanchep Ch Ch Ch Ch 16 67 23 26 Perth ■ VIP Esperance * ~<-J VIE • l Ch 16 Ch 67 Ch 16 Ch 67 Ch 16 Ch 16 67 23 26 Ch 16 ~~ ~~ Ch 26 Ch 02 )7 Existing Seaphone/Solas Stations Ho b art * Ch )G ~ Ch2l New Solas Stations C~:e~ouga,nville Sou * Daytime hours only p Ch 16 Ch 67 This map shows the regions on Australia's coastline covered by OTC's Seaphone service. The relevant VHF channels are 23, 26 and 27, corresponding to 157.1 5, 157.3 and 157.35MHz on transmit and 161.75, 161.9 and 161.95MHz on receive. Soon, virtually all of the eastern seaboard will be accessible by Sea phone. ply 12 volts to the microphone circuitry. Inside the microphone housing are two printed circuit boards, one for the keyboard and the other for the 44-pin dedicated Motorola microprocessor which has its own inbuilt memory (RAM and EPROM). The processor provides the DTMF (dual tone multi frequency) tones for dialling and the code which identifies every Seaphone licence holder. Each Seaphone licence holder will be allocated a subscriber number but, for security, the code stored in the microphone electronics will be known only to the OTC computers. Note that all the existing OTC Seaphone services will be available to marine radio users but the new automatic service will only be usable with those radios which have been modified with the new microphone. Features of the service The automatic Seaphone service will be used as follows. The user switches the VHF marine radio to a free channel (eg Ch 02, 23, 26 or 27) and listens to ensure that no calls are in progress. The phone number can then be dialled, preceded by the STD number for Australian calls or by the country code for international calls. The user then presses the "*" button to transmit the stored user 's auto-Seaphone identifier to OTC's computerised radio base station. The user 's code number is then validated by the computer which checks to see that the code is valid and that bills have been paid. A brief voice announcement will then state that "your call is being connected" . Normal ring tone will be heard and when the called party answers, call charges are recorded by the computer. While the call is in progress, the user operates the press-to-talk button in the normal way. When the call is finished, the customer presses the " #" button to reset the system. If a call can't be connected, a voice announcement tells the user JANUARY 1988 69 automated voice announcement will respond to the call and if there are messages, the system will automatically connect and bill the Seaphone call to the shore telephone subscriber who booked the call earlier. That's a nifty arrangement which must have taken a lot of thought to develop. Dial 999 for emergency Mr Kerry Stratton demonstrates the new push-button microphone which is the upgrade for VHF marine radios using OTC's direct-dial Seaphone service. Heyden-Spike Ltd (Brookvale, NSW) developed the new service and the microphone. that message and if the code is not valid or recent accounts have not been paid, the user is connected to a (human) operator at the radio base to sort out the problem. Naturally, calls can be made from shore to ship but they have to be made via the OTC base radio. This means that a telephone user calls base radio and asks to contact a person on the water. Whether or not the call makes immediate contact depends on whether the marine radio is turned on and tuned to the calling channel, and is within range. Mailbag continued from page 3 there are two faults, a broken earth and a defective neutral. The problem is that there is no indication of either of these faults until both of them occur. I know a plumber who carries a set of automotive jumper leads and he uses them to bridge the gap when breaking a run of pipe. With MEN, any green-wire fault currents should return to neutral if the water pipe is broken, with no significant voltage being developed above earth. It wouldn't be a problem and hence plumbers would not be aware of it unless there was a faulty neutral, so perhaps faulty neutrals are not un70 On the existing Seaphone service this situation is taken care of by the message system. Callers leave messages with the base radio and when the boat-owner calls in, the base radio operator can place calls. As can be imagined, this process can be quite time consuming, both for the radio operator and boat owner. In the new automatic Seaphone service, the boat owner merely presses the "*" button on the microphone at any time to interrogate the OTC system for "any Seaphone calls on hand". An SJLICON CHIP common in the system. Maybe plumbers detect them more often than the County Council people. A. Lackey Collaroy Plateau, NSW Extra earth lead Thanks very much for your article on electrical safety [November 1987). All my life I have been concerned about electrical safety, not so much for myself but for others, particularly those nearest and dearest to me. You should write some more on the subject. I too am super-cautious. Thirty years ago I fitted an additional earth In a distress situation, it is normal practice to use Channel 16 with voice contact to the base radio or a nearby vessel. With the automated Seaphone service though there is a quicker way to draw attention to an emergency situation. By dialling 999 on any OTC Seaphone channel, an immediate alarm will be activated and the computerised system will automatically display the vessel's name, call sign, type and the owner's name and address on the screen at radio base. The emergency 999 function will override any Seaphone call in progress on the selected channel. Cost of the new service The new service is not expensive, particularly as far as the initial setup costs are concerned. The cost of the new microphone plus fitting to a marine radio is $249. Phone charges are $1.30 per minute. At the time of writing OTC was considering the introduction of a 6-second normal tariff charge. On the face of it, this new automatic Seaphone service from OTC must be a winner. It is convenient, easy to use, and reasonably priced. ~ from our washing machine to the cold water pipe. You have my support and best wishes. N. Walker Como, NSW An excellent magazine Yours is an excellent magazine. I had almost given up buying electronics magazines but I will take a subscription to yours. I hope the standard of your first issue is reflected in the future. Being a mechanic by trade and a hobbyist only in electronics, I find your articles well written and understandable. A. Glover Cootamundra, NSW