COhERENT CW Compiled by G31RM Issue number 18 The Newsletter It is getting more and more difficult to find something of interest to write as I now seem to have mentioned all that is available in the way of articles and there is not an overwhelming amount of information coming in from members. I think I will have to adopt a quarterly Newsletter in future. This seems a convenient time to do this making Newsletters due at the beginning of March, June, September and December. Publicity Peter SM6FPC tells me that the Swedish teleprinter group SARTG is running a series of articles about Clover in their magazine. I have another update on CCW in the May issue of QEX - the ARRL asked me for it! Commercial transceivers I saw an article in the May issue of The Lowdown which described briefly what was called a Beacon Grabber. This set me off thinking about the use of commercial transceivers for CCW for ft is obvious that if these can be used, a very large obstacle to the extended use of CCW will have been eliminated. In the article mention was made of the TS430- The article further stated that 'since all mixer injection frequencies in this receiver are developed (synthesized) from the master oscillator, the result is that the receiver/ beacon grabber can be precisely tuned to any frequency within the range of the receiver. I have been trying to find confirmation of this information for a long time and have written to several U.K. dealers though they have not been very helpful. Does anyone know of any other transceivers which operate the same way? The article goes on to give brief details of how to lock the master oscillator to an external frequency standard. The standard actually used was Loran though obviously others can be used. Such transceivers, suitably locked, would make the CCW station so much simpler to build as all that would be required would be a standard, a keyer and the Petit filter. Kurt OE1KYB did a similar modification on his TS940 though, from the circuits he sent me, there was much more involved than simply phase-locking to a suitable standard. I have also looked into the possibility of using the much newer TS450S which uses a single oscillator to control all frequency determining circuits. There is an optional temperature compensated crystal oscillator (TCXO) which claims a stability of at least -5 parts in 10 million. This is slightly better than the stability originally specified for CCW. The output of this oscillator is brought out and can be divided down for the filter. If anyone has a transceiver fitted with the TCXO it would be interesting to see if CCW can be used. A check on the stability of these transceivers would be useful if you are able to carry one out, I say again, if these are suitable, you only have to produce the Petit filter and keyer to be on the air. At least on the TS450S, a simple modification (without leaving any trace on removal) can be made to use an external standard. It is just a matter of cutting two jumpers provided for the addition of the TCXO and adding suitable leads to connect to the external unit. A relay could be added so that with the relay on the standard is connected and vice versa. A very nice additional feature of the TS450S is that ft will tune in 1 Hz steps against the 1 OHz of the TS430. The more expensive Kenwood transceivers use the same system. Some of you may even have other suitable transceivers without knowing ft. I have no knowledge of any of the other makes of transceiver. The Toni-tuner -- I would just like to mention this very useful device which can be built on a board's"upplied by BARTG. It is an audio frequency meter using a row of led's. I have used one for years and John Stace has now said that his has been invaluable. One of the most useful things I have found ft will do is to allow accurate netting of CW stations. One range on mine is calibrated so that the center LED lights at 800 Hz (to be changed shortly to 500 Hz for CC". I then tune a station so this lights and, as my transceiver has a beat note of Boo Hz (CCW - 500 Hz) the transmitter comes on dead an frequency. It has numerous other uses. If any member would like to know more please write in. An Iambic keyer Carl Knox in Minneapolis wrote enquiring about o activities and enclosed a copy of a keyer he h designed. It uses CO series devices and requires external clock so it looks ideal for CCW. Circuit available from me. R.f. synthesizers As a result of my note in the last issue, B VE3DPB and CIO W6HDO both made enquiri regarding the Motorola MC145163 and both came up with the same answer - this device does not appear to be available in the U.S.A. I wonder how many who read the article in QEX spent time trying to find a source of supply! However I have found source in the U.K. now but am still trying to get hold of a full data sheet. I do have sufficient information to be able to put a circuit together. The devices are about E20 each as single items but I have a way getting them at the 100 unit price which will worry out at under 210 each. If anyone would like to try this interesting device (remember though that the referenced divider is binary though the programmable divider is bcd which, as I mentioned before, makes a very convenient readout possible! please let me know so I will know how many to order. I have also obtained a few Motorola MC145156P1 seriall programmed phase locked loops at a very much reduced price. They are thought to be have been removed from working synthesizers. Anyone like to try one at 2 each? Clover No more news at present. Bernhard DF3CT Bernhard is a regular correspondent with long a interesting letters and one of the first to have contact on CCW since we tried to revive the system He has sent a copy of an article from CQ DL - so is in German - describing a QRP CW transceiver for 7 MHz. A circuit diagram and layout Oans are provided and a PC board is available. The article I described as a European adaptation of the W7EL circuit which appeared in the August 19W issue of QST. Let me know if you want photocopies (four pages). Cliff Buttschardt W6HDO Apart from telling me about the Motorola device, Cliff also tells me that he is on one of his three month trips at sea. On his return he wili be prepared to put a coherent signal on 7030 KHz with a full kilowatt. He is not too keen on doing this for too long a period as a lot of low power activity takes place around this frequency in the States. He is suggesting 0600 GMT. There should be a very good chance of copying these signals over here. Identification would be 'HDO MBAY". If you will be able to listen for these signals either in the usual way or coherently please let me know. Arrangements can be made with Cliff and I will let those of you who can listen know as soon as arrangements have been made. Peter SM6FPC Peter has all the pieces to build the filter and hopes to start soon. There was a reference on 198 KHz (the same frequency as Droitwich) which has now closed down so there is only one reference frequency in Sweden now and it is on 1 00 MHz - for those who live in Stockholm. However, Peter has a reference locked to a Danish long wave station which he hopes to use for CCW. He also has some ideas on how to use a standard commercial transceiver for CCW but these are not ready for publication yet. Gary G41-RA Gary has written to say that his CCW station is now fully operational but, for personal reasons, it is difficult to fix times for contacts. I think it was John Stockley (but I may be wrong) who said that it was advantageous to balance other op-amps in the filter in addition to those already balanced. Gary has now said the same thing regarding the G4VSO synthesizer. Is there a moral here - namely, balance all op-amps even though they are supposed not to need it? He now intends to have a go at the Howes kits. Finally, my own efforts At long last I think I am about to be operationalwith CCW. I have done all sorts of things with the published CCW circuits - and a lot of others - but have now decided on my final layout. All I have to do now is to connect the standard to the transceiver and I should be on the air on all bands with up to 1 00 watts of output. First transmissions will probably be on 7030 or 14060 during the evenings. If anyone with a working CCW receiver would like to listen I will try and find a suitable time though my operating time is restricted somewhat during the summer months. All for now 73 Peter Lumb G31RM 2 Briarwood Avenue Bury St. Edmunds Suffolk IP33 3QF England