C:@ - (@:: - U-J - = L_:@ inn V3 1 I c---- c1 t:D -@@ C3 :=. I F;: 1-1 t'-,l *-= " sEa I SiF@ S=-@ L-t C-_ @4 Apology :::: .... To Ian Butterworth for getting his call wrong - it should be G4BZO. Correction :::: On rebuilding I have noticed an error in the display circuit of should be 18K. Publicity :::: .On rebuilding I have noticed an error in the display circuit of the audio synthesiser. The 621: resistor u ici Y.... Claude will be reprinting my short article in Sprat in his CW magazine AIA translated into French and Bernhard says it should appear in either the February or March issue of the German magazine. Yeovil Amateur Radio Club :::: .... Bert 63RHI will be giving a talk on CCW to the sixth QRP convention to be held at The Preston Centre, Monks Dale, Yeovil on May 13th. New members :::: \ \ EASYU Goran Hosinsky ZLIBTT Colin Mackay 3A2LF Claude Pa55et Arecida 43 U2/597 Glenfield Road 7 Rue de la Turbie E-38780 Tiiarafe Glenfield Mc 98000 La Palma Auckland Monaco Canary Islands New Zealand G3YCZ Barrie ? 64YND David Evans 67CBX Bernard Greenall Beacon :-:. .... I received a letter from Bill de Carle just after posting News3 to say that VE3DPB has been unable to re-activate the beacon. Eighty tetres :::: 19 y .... John Stace wonders if a suitable frequency can be arranged for 80 metres. How about using 30 up as has been suggested for other bands! Ray Petit survey :::: I hope a lot of you have sent your survey replies direct to Ray as I have only received seven replies which I have posted to Oak Harbor. Clover :::: No doubt you will wonder what this is all about. As a result of a letter written to Ray Petit by Jack Hollingworth I have been fayoured with a copy of his reply. It appears that many of us are a2azed at how inefficient h.f. packet operation can be. Clover is Ray's latest and uses a sional which is carefully shaped in amplitude to produce a very compact spectrum with no sidelobes. Twenty-five puises per second appears to be just about optimum on h.f. and at a standard 100 Hz channel spacing a Cloyer signal in an adjacent channel is expected to cause no interference even if it is 60 dB stronger than the in-channel sional, Try to beat that! The first prototype system sends 1, 2, 3 or 4 bits of data per pulse. Reed-Solotan codes of adjustable block length and code rate bridge over the 'dro , pouts' of selective fading. The system has means for evaluating the channel conditions and for automatically setting the modulation form.at and RS code to iaximise throughput, taking into account the coding overhead and the costs of r Etries when they are needed. As in CCW, there is a need for extreme frequency precision. Ray wrote software to track and lock on to a signal but, as amateur equipment is not stable enough, he is now building two complete transceivers which will be capable of compensating for the errors of their frequency standards by regular observation of WWV sionals.Ray's letter then goes on to give short notes of the proposed 5ystes and concludes that the Clover system has typicallyte:; times the throughout per bandwidth of any other data mode in amateur use including CV1). What seems strange to seis that Ray wrote a paper detailing the system and submitted it to @ST but they refused it without comment. I wonder why. for publication. If Ray would like it publishing I have offered to try an get the RSCB to accept the article .No doubt you will wonder what this is all about. As a result of a letter written to Ray Petit by Transmitters/receivers :::: I wonder if any of you have had any thoughts an suitable transmitters and receivers. The general opinion is that something simple for one or two frequencies on one or two bands will be the easiest way to start. I have had a look through the various magazines I have and have come up with three possibilities which are listed below. All can be adapted for CCW by making the Y.f.o. act as a buffer. H.f. synthesisers :::: Ray Petit has sent se list. It is very similar to the one in the article. a copy of an article from the American Has Radio which I have added to the old CCWN 76.66 which I listed as number 21 but it is a more complete Information sheets :::: 24.GRP CW transceiver by NZ56 and N5HNN published in 77 Amateur Radio for June IqB9 A fairly easy to build circuit using a ring diode mixer. Intended for 30 or 40 metre bands with about 3 watts output. (6 pages) 25.The GRP three-bander by KH6CP published in 9ST for October 1989 This one uses an NE602 as detector (a lot easier to use than the MC1496) and covers 18, 21 and 24 MHz though these could be changed. (6 pages) 26. Direct conversion receiver for 60 setres published in July/August 1989 Elektor Circuit just gives a mixer (CA3080E) with oscillator using BF494. selectivity from a special feedback circuit. (3 pages) It claims to get its gain and 17. Frequency synthesised local oscillator system for the high frequency amateur bands by Ray Petit W76HM published in It i Has Radio for October 1978 Uses about 14 i.c's. and covers 5.0 to 6.0 Mhz in 100 Hz steps or 1.1 to 1.6 Mhz in 10 Hz steps. I Mhz standard (not shown in the article). Tuning is by 4 bcd switches. (6 pages) Requires a News from members :::: DF3CF:Bernhard is making good progress and should be starting on an audio synthesiser in the near future. as though he say well be the first non-U.K. station to be operational. GOMIF:Ian has started building his frequency standard. GXCH:John has successfully completed the VE30BE keyboard and is building the filter. 636RT:Bill has completed his frequency standard and is starting on an audio synthesiser. 67-IRM:I now have a frequency standard locked to Droitwich, the Petit filter and an audio synthesiser completed. Now I as trying to write a program for the SDS Archer computer to send and receive CCW though this is just as a change from building. 63RHI:Bert is still making progress with a large part of the digital circuitry completed. 63TFV:Ed is building a new all band CW transceiver. 63TMQ:Dick now has a stable standard completed. 64HCC:It looks as though Michael will be starting on his standard soon. 64LRA: Gary has completed the VE30BE standard and the filter and is starting on an audio synthesiser. It looks 73 de 63IRM