COHERENT C.W. NEWSLETTER Compiled by G 31 RM, Issue number 20 Publicity My short article in the R.A. F. magazine ORV resulted in six members asking to join us so the exercise was worthwhile. Geo Longden of the Fists CW Club has reprinted the article in his newsletter Key Note and Rick Sterry will be printing a few notes in the January issue of RadCom. Tests My thursday evening transmissions have been received by GOSBQ, G4SYC and SM6FPC and I have had contacts with the last two - sending as CCW and receiving as CW. Signals were readable but only about strength 2 or 3 as would be expectedat that particular time of day. Peter, SM6FPC,is also calling on 7030 about the same time as Ihave been doing and is also calling on 3550 at 2045 gmt. On the 12th of November I managed to copy his callsign in the CCW mode on 3550. On the 1 9th signals were 569 receiving as CW so we tried CCW with excellent copy both ways. However, I kept monitoring as CW and Peter's signals disappeared in the noise after about fifteen minutes but I still had tqLqgpy as CCW. We tried 3550 but without success. Returning to 7030 1 could not copy anything as CW and only occasional letters as CCW. We will be continuing these tests and would appreciate any reports of reception. Infcrmation sheets It is some time since I listed information sheets that I have collected. The following are recent additions - photocopies are still five pence a page. 43. K4EEU frequency standard from Ham Radio for February 1974. This is the original frequency standard used in the 1975 experiments. It is not oven controlled but uses temperature compensation capacitors. (4 pages) 44, Ein QRP-CW-Transcerver fOr 7 MHz from the German magazine CQ-DL for January 1989. This is an adaptation of the very popular W7EL transceiver - in German of course. (5 pages) 45. Electronic keyer by Cad Knox KBOEBG. Uses standard logic devices and an external clock so December 1992 synchronization for CCW can be provided by using suitable dividers. (2 pages) 46. 8o metre CW/SSB direct conversion phasing receiver by G3PCJ- Complete instructions including board layout. (8 pages) 47. So metre CW/DSB 50 watt PEP transmitter by G3PCJ- Intended for use with the above receiver using the vfo in the receiver. Board layout is included. Q pages) 48. Clover by K9GWT and W7GHIVI from CQ Magazine for May 1992. The latest summary of the Clover system to be published. (4 pages) 49. PC-Clover technical update and specifications. Details of the first release of the PCI-4000 board and software from Bill Henry. Includes photo of the board, specifications, modes available and radio requirements. (8 pages) 50. CW interface for IBM type computers. I mentioned last time that I had found a CW decode program which I like and a number of members have asked for copies. This interface uses an MF10 filter followed by a demodulator keying indicator and level shifter to feed into the RS232 port of the computer as required by the program. (1 page) 5 1. A receiver spectral display using DSP. This is Bill de Cade's article in OEX for January 1992 for which he can supply boards, software and completely assembled units. (7 pages). I also have a copy of the notes supplied-with the board giving more technical details. (8 pages) In addition I have details of the White Rose transceiver published-in RadCom some time ago and the CVF40, DCRX, CTX40, CSL4 and ST2 boards available from Howes Communications. These occupy quite a lot of pages and U.K. members will have easy access to them If they need them. If any overseas member is interested please write in and ask. Commercial transceivers Cliff W6HDO has taken up the question of synthesizedtransceiverswfththeA.R.R.L.laboratory and we are hoping that they will keep their promise and help to compile a list of fully synthesized transceivers. By fully synthesized we mean those transceivers where all frequencies are derived from one oscillator which, provided it is stable enough, can be used for both CCW and Clover. In many cases it should be possible to feed in an external standard if required. Ray Petit tells me that he has been urging radio manufacturers to make their products CCW and Clover compatible in frequency stability. I think they are getting the message. Droitwich As a result of my remarks about Droitwich last time Geoff G4SYC has written to say that G7EAH at Manchester University has been monitoring 198 KHz against an atomic standard for some time and has found some alarming glitches well outside the stated accuracy. It appears that the final amplifiers, of which there are quite a number, are not all used normally but some of them are used on a rota basis. When one is switched in and another is switched out considerable deviation takes place and this has been confirmed by the B.B.C. engineers. The station is definitely not suitable as a standard to drive CCW or transceiver oscillators. However, I still think it can be used with a long time constant for checking other oscillators. My own checking system shows excellent agreement between Droitwich and my oven controlled oscillator except that periodically there is a sudden jump taking several seconds to re-stabilize. I wonder if this is when they switch amplifiers. Perhaps I am not checking my own oscillator but am checking Droitwich instead! I Clover PC-Clover is here! I had a letter from Bill Henry early in October to say that the PC-Clover boards should be available for sale early in January next but that some would be made available for experimental purposes slightly eartier. It is understood that these will be for those who have expressed an interest over the period that Clover has been developed. As a result I am hoping to have a board by the time you read this Newsletter and to have Clover on the air. For the time being let me say that the price will be $995 in the States for which you will receive the PC-Clover board, manual and terminal software. To use the board an IBM compatible computer is needed with at least a 286 processor. The software will be downloaded from disc so that updates can be provided without the necessity of using programmed roms. It will also be easy to use third-party software. All processing is done on the board, the PC acting merely as a power supply, storage system and terminal. The main connections from the board use a DE-9S connector and consist of audio in and out, selcal and push-to-talk. A multiple lead is provided so connection to the transceiver is easy. The transceiver must be stable and have tuning increments of 10 Hz or less - most of the new models available should meet these specifications. An on-screen tuning indicator is provided. I will not go into the various modes which are available; they are in the technical data sheet. I have obtained permission from the licensing authority to use Clover and have also asked the R.S.G.B. to enquire if general permission for the use of Clover by amateurs in the United Kingdom can be obtained now that hardware and software will soon be available. The F.C.C. has agreed that Clover is designated J2D in the United States and I assume that this will be accepted here. A reply from John Bazley appears to assume that the Agency automatically accepts this and there is no need to contact the Agency. -H-A-PPYCHRISTMASAND BEST WISHES FOR 1993 2 Briarwood Avenue Bury St. Edmunds Suffolk IP33 3QF England