CCW NEWS Issue number 9 Compiled by G3IRM December 1990 General notes I had a long letter from Bill de Carle a month or so ago and 11 proved to be Interesting as all his letters are. He usually makes some very good points. First he mentions that it looks as though CCW may go the same way as it did In the States - more Interest than commitment and not enough of either lo make a go of It. I hope he proves lo be wrong. I have always thought that the main problems have been that high frequency stability and home construction were the difficulties in the States. It is now a lot easier to attain the required stability than it was 1 5 years ago and I am hoping that the actual construction can be made easier. Kurt ArIl sent me samples of his three boards for the version of the filter in QST that I mentioned last time and excellent boards they are. I have been able lo find all components here in the U.K. with the exception of the swicthes though it is possible to mount normal switches on a panel and run wires to the boards. I hope Kurt can make the boards available and I have written asking if he can. If I hear belore I send this Newsletter out I will include a note on the second page. Bill goes on to point out that both CCW and Cloverleaf go to quite a lot of trouble to use narrow bandwidths - all very commendable - and more stations can be packed Into the available space In the bands. This would be ideal if we had exclusive sanctions of The bands available or if everyone changed over to those frequency saving systems. But they won't and the trouble will be that we will have to contend with stations tuning up and others who don't show sufficient consideration. Again, using low power, other stations often don't listen out before transmitting and may not even hear low power Stations. For this reason I am aiming for at least 20 watts output. CCW has advantages when there are other stations on nearby frequencies and I hope Cloverleaf will prove to be the same. We will have to wait and see. A further point Bill makes is that some of the signals we receive are well above the noise level and can be read easily. Others are so far below the noise we can't receive them, anyway. So we spend a lot of time trying to receive signals which are Just above the threshold of the noise. For these signals the enhancement provided by CCW and Cloverleaf may be enough To make all the difference. 'Whar we want", says Bill - and I agree with him - "is a simple and cheap system which can be added to existing h.f. stations that will give a whole lot of improvement over what we have now. HQ goes on to say 'I have been doing some calculations on block coding. This scheme Is attractive because it In- volves only writing software for our computers - 11 recovers messages quite independently of the phy- sical means used to transmit them. No modification of existing rigs or new hardware would be needed. 11 we could come up with something standardized, it would spread round the world right quick, because these days most hams are using computers anyway, and 11 doesn't lake much effort to copy a disk.' He then goes on lo give a short outline of his suggestions and the problems which will be Involved. I should think a lot of people would have thought that such a system would be a good idea. With all the bright brains around these days isn't It a little surprising that no-one has come up with a practical solution? Perhaps the computer programmers haven 'I thought of it. Wouldn't it be nice if such a system could be produced? I await developments Bill, as we all do. New members G3MBN Brian Gibbs, Neslon GI4KIS Brian SheePwash, Antrum Notes from 1 975 - tune-up Connect the power supplies and all Inputs except the incoming signal. Apply power and, if the balancing potentiometer have been set randomly, you should hear a steady lone at the output. The tone should also have very light, rapid clicking sounds In the background. N ow adjust the potentiometer for a null. Rotate the phase switch through Its entire range and no noticeable change in output should be noted. Now Introduce a very small signal Input at precisely the center frequency of the filler. This is exactly one quarter of the switching signal used for the input mixer. The level of this input should be from 10 to 30 mililivolts. As the signal Is connected you should hear a rise in the amplitude of the output signal and thiss output will be noticeably delayed from the input when you connect and disconnect it. II you now connect a low level non-coherent signal from your receiver into the filter you should hear low level random pulsing tones in the output. When operating on the air it is extremely important that the desired signal level Is not more than about 50 millivolts. Otherwise the filter will saturate and will not function properly. Undesired signals can be permitted 10 reach I or 2 votes and the filler will reject them satisfactorily. This Is an abbreviated version of the note by Ray Petit In the original W6NEY CCW newsletter for June 1 975. Further developments lo Iambic coherent CW Integrated circuit using Altera EPLD's by Colin Horrabin G3SBI Since the articles In the CCW Newsletter and In Radcom technical topics on the use of an EPLD as a keyer, a number of enthusiasts have purchased chips from me to use in their keyers. Most amateurs are not Interested in CCW Operations (continuously running 1 KHz clock) and are using them as straight iambic keyers using the gale pin lo start and slop an external RC oscillator lo minimize current consump- tion (15 microamps). I have received some useful feedback on the ability of the chip to generate CW In a forgiving manner and one user rateS it as 'much nicer than the Curtis chip, where he underlined the 'much'. Although not many additional components are required lo get operational, I have been asked about printed circuit boards. 11 Is something I have been reluctant lo do but I have made prototype boards which will be available 21 some point. 'Paddle l' Is just the basic chip with CCW at 1KHz clock and onboard RC oscillator - no digital speed control. The size Is 1.45"xl ' or 2.2'xl ' with holder for three silver oxide cells. 'Paddle2' contains all functions including weight control and monitor oscil- actor - size 2.2'xl'. These are quite small and Can be built into the paddle key. I am hoping that these will be available in due course. A further development 'Paddie3' is a memory keyer. A prototype using a 24 cell EPLD has been successfully tested and a printed circuit layout produced but not yet made. This mounts four chips - an EP900 EPLD and 2 16k memory and Iwo small outline chips - a 4093 and 4040 CMOS. The keyer works as the original with variable or digital speed control. The memory is available as four pushbuttons to replay instantly any one of four messages on four banks - a switch selecting a bank. To record, a switch Is thrown to 'write' and a pushbutton pressed and the key is used to generate the message. On replay, the depressing of any pushbutton starts the message associated with that pushbutton. 11 either runs lo completion or the operation of the key slops it and sends over the top. Depressing another memory pushbutton Immediately starts a new mes- sage at any lime. I did not intend to, but it seems likely that It may be necessary lo allow a lK message lo repeal Itself until slopped if beacon operation is required. Power consumption Is 20 microamps standby and 0.5 milliamps operating (monitor speaker off). This would probably be about 0.5 milliamps continuous for CCW due lo the constant running clock. PCI3 size Is 2.6'xi.5'. This would probably have lo be sold as an assembled board due lo the use of SO packages. I think cost will be In the region of 950 as I could not all to buy the components In quantity. All the PCB's have a row of connections for the and selection of options, etc. As I sald at beginning I did not want to get Involved with PC as they take time and money! So we will have to see how it goes. An interesting point In PCB design that you reallocate the pin functions on the EPLD make the PCB layout easier. on a slightly different point I do have an EP61 0 c design that will act as an audio synthesizer. 4 Mhz Input will give a quadrature clock at 1 KHz. Seven Input lines enable the frequency output lo be moved In approximately 1 Hz steps +/- 64 Hz either side 1 KHz. Logic levels of 0000000 for D7 lo D1 give KHz. 1 1 1 1 1 11 is +1 Hz. 1 1 1 1 1 1 0 Is +2 Hz. 1 1 1 1 101 is + 3 Hz. etc. 0000001 Is - 1 Hz. 0000010 Is -2 hz. 0000011 is -3 Hz. etc. If anyone wants one the price is L:8.50 or send me an EP61 0 for programming. Write lo Colin at 71 Duckworth Grove, Padga Warrington WA2 OQU. With development of this audio synthesizer chip and the keyer chip which Colin has produced we are our way to simplifying the whole setup required CCW. He did suggest that he may be able to get most, if not all, of the filler on to another chip. I know this is putting a lot, on to one member but Colin the only one who can do the programming! Thanks Printed circuit boards The three boards for the OST filler design can obtained by sending a Eurochoquo amounting 750 Austrian schillings to OEI PYW at Print Techni Slumpergasse 34, A-1060 Wien, Austria quoii OE1 KYB W6NEY filler boards. K4EEU standard Thanks to both Peter SM6FPC and Goran EA8YU now have copies of the original article from H Radio Magazine describing this most excelle standard. Copies are available for the usual il pence a page. There are 4 pages. News from members Not a lot this time though one or two report making slow progress. My own efforts are being held up due to other things and some complications with the synihesizer mixing but I am moving slowly forward. I have the Clover transceiver almost complete - all sections built but still the final wiring and testing to be done. Kurt (Oe1KYB) and Bernhard (DF3C look as though they are nearly operational. A HAPPY CHRISTAMAS AND 1991 TO YOU ALL QTH- 2 Briarwood Avenue Bury St. Edmunds Suffolk IP33 3OF England