Contents Contents
Total Page:16
File Type:pdf, Size:1020Kb
Contents Contents Contents............................................................................................ 1 Committee Contacts ......................................................................... 2 Editorial............................................................................................ 4 3cm Signal Strength Meter............................................................... 6 3cms Tips 2....................................................................................... 7 A Video Inverting Amplifier .......................................................... 12 24 cms ATV Transmitter Review................................................... 14 The TV History Man ...................................................................... 17 Two Satellite Receivers from One Dish.......................................... 25 Satellite TV News........................................................................... 26 Report from G3VZV on Outcome of IARU Region 1 Conference. 39 A Tale of Alexandra Palace............................................................ 43 BATC Accounts for 1995............................................................... 46 Beyond TTL # 12............................................................................ 48 SPLASH - a Review ....................................................................... 54 SSTV or FAX? ............................................................................... 63 TV on the Air ................................................................................. 66 Second Welsh Microwave Fast Scan ATV Tests ........................... 73 BATC Rally 97............................................................................... 75 Signal Calculations......................................................................... 76 An Introduction to One Group’s 24GHz Experiences.................... 80 Post and News................................................................................. 88 For Sale........................................................................................... 92 Wanted............................................................................................ 96 Index of Advertisers........................................................................ 96 CQ-TV is produced on a P6 Gateway 2000 PC computer system, using the Word for Windows word processing package. The camera ready artwork is produced on an Hewlet Packard LaserJet 4 printer. Edited by Ian Pawson with help from Trevor Brown, proof read by Peter Delaney. All rights reserved, all wrongs denied. 1997 by the BATC. Printed by Cramphorn Printers Ltd., 15c Paynes Lane, Rugby, England 1997 by the BATC CQ-TV 177 Page 1 Committee Contacts Committee Contacts BATC Chairman Trevor Brown G8CJS Club affairs, Video tape library, Technical queries, especially relating to handbook projects. 14 Stairfoot Close, Adel, Leeds, LS16 8JR. Tel: 01132 670115. E-mail: [email protected] BATC General Secretary Paul Marshall G8MJW General club correspondence and business. Library queries relating to the borrowing or donation of written material. Fern House, Church Road, Harby, Notts., NG23 7ED. Tel: 01522 703348. Email [email protected] BATC Hon. Treasurer Brian Summers G8CQS Enquiries regarding club finances, Donations, and constitutional enquiries. 11 Harefield Road, Uxbridge, Middx, UB8 1PH. Tel: 01895 810144, Mobile 0850 014892 CQTV Magazine Editor Ian Pawson Anything for publication in CQ-TV, Articles, Review items, Letters to the editor, and other material except as below. 14 Lilac Avenue, Leicester, LE5 1FN, England. Email: [email protected] Photographs for the CQ-TV covers:- Patrick White, Swyncombe, 8 Kingswood Court, Maidenhead, Berkshire, SL6 1DD, England TV on the Air:- Graham Hankins G8EMX, 11 Cottesbrook Road, Acocks Green, Birmingham, B27 6LE. Tel: 0121 707 4337 Satellite TV News:- Paul Holland G3TZO, Chatterton, Chapel Lane, Threapwood, Nr. Malpas, Cheshire, SY14 7AX. Tel: 01948 770429, Email: [email protected] CQ-TV Advertising Manager: Dave Hemingway, Ivanhoe, Glen Road, Hindhead, Surrey, GU26 6QE. Tel: 01428 604645 CQTV Awards:- Bob Webb G8VBA, 78 Station Road, Rolleston on Dove, Burton on Trent, Staffs., DE13 9AB. Tel: 01283 814582 Page 2 CQ-TV 177 1997 by the BATC Committee Contacts Exhibitions Rally 96:- Mike Wooding G6IQM, 5 Ware Orchard, Barby, Nr. Rugby, CV33 8UF. Tel: 01788 890365, Fax: 01788 891883, Mobile: 0860 857434 Email: [email protected] CAT 96:- General arrangements and information about talks to clubs, demonstrations, lectures, etc. Paul Marshall G8MJW - Details above. Club Sales Members Services:- PCB’s, components, camera tubes, accessories, etc. (NOT PUBLICATIONS). Peter Delaney G8KZG, 6 East View Close, Wargrave, Berkshire, RG10 8BJ. Tel: 0118 940 3121 Publications:- Handbooks, Back copies CQTV, and anything related to the supply of BATC publications. PLEASE NOTE NEW ADDRESS:- Paul Marshall, Fern House, Church Road, Harby, Notts., NG23 7ED, England. E-mail: [email protected] Membership Anything to do with membership, including new applications, queries about new and existing membership, non-receipt of CQ-TV, subscriptions, membership records, data protection act. Dave Lawton G0ANO, ‘Grenehurst’, Pinewood Road, High Wycombe, Bucks., HP12 4DD. Tel: 01494 528899. E-mail: [email protected] Club Liaison:- And anything of a political nature, co-ordination of ATV repeater licences. Graham Shirville G3VZV, The Hill Farm, Potsgrove, Milton Keynes, Bucks., MK17 9HF. Tel: 01525 290343. Email [email protected] Contests:- Richard Guttridge G4YTV, Ivy House, Rise Road, Skirlaugh, Hull, HU11 5BH. Tel: 01964 562498 BATC BBS Sysop:- Brian Kelly GW6BWX, 12 Cotswold Way, Risca, Gwent, NP1 6QT. Tel: 01633 614376, BBS: 01633 614765. Email:[email protected] Repeater Liaison:- General enquiries and repeater affiliation. Graham Hankins G8EMX, 11 Cottesbrook Road, Acocks Green, Birmingham, B27 6LE. Tel: 0121 707 4337 1997 by the BATC CQ-TV 177 Page 3 Editorial Editorial The front cover shows a picture of the LT75 laptop VT edit controller from Panasonic. The tape format is called DVCPRO and is digital component. The format utilises video compression to reduce the video signals to one fifth of their original size. The compression is on a frame by frame basis and as such allows frame accurate editing. Powerful error correcting coding ensures minimal dropout. DVCPRO is a format aimed at broadcasters and reflects a broadcast price. Panasonic are also launching a domestic version called Mini DVC. This will use a smaller cassette but feature the same digital encoded signal. Mechanical adapters are also planned rather like the VHS C format used to enable the domestic tapes to be replayed in dual standard professional machines. Digital domestic equipment had to come and should enable production work and the inevitable multi generations to take place with acceptable end results unlike the present VHS standard. Watch this space. CQTV 177 is my last offering as CQTV editor and CQTV 178 starts with Ian Pawson in the chair. Ian has held my hand and done all the back room work throughout my editorship and has now taken on the full mantel. I hope you will all show him the support and help you have shown me on what is a difficult and time consuming task. The down side, or upside of this change however you view it has enabled me to return to my column Beyond TTL which starts again in this issue with a new CPU the PIC 16C84. The rest of the editorial team remains unchanged with Patrick White designing front covers, Dave Hemingway as advertising manager and Dave Aston as draughtsman. I am still BATC Chairman and I am sure Ian will find me one or two corners to fill. The new format of colour pages and wider blend of articles ranging from Dickey Howett regular features on characters and events from TV history will I hope continue along with constructional projects such as the 24 GHz article that starts in this issue. Good luck Ian I am sure CQTV is in safe hands. TREVOR BROWN, BATC Chairman. Page 4 CQ-TV 177 1997 by the BATC GB3XT Kits & Bits. GUNNMOD2 3cms TVRO3 ATV Tuneable 24cms HIGH GAIN ATV. TX. kit. Very IF/RX. kit. Fully featured LOW NOISE popular full feature Gunn 750-1700MHz input. GASFET PRE-AMP diode TX. Complete with 12vDC operation. No kit. 40db gain 1db NF. pre-tuned oscillator head. setting up or alignment with band pass helical £30.00. PCB. kit less required. £50.00 filtering. 12-18vDC via oscillator £20.00 coax. £60.00 24cms ATV TX. kit. Full 3cms LNB’s. Brand new DTMF DECODER spec 5ch max. 2W o/p. circular input. Fit 38- kit. Very high quality Filters for video & audio. 40mm mounting. will decoder IC. All o/p’s 12vDC. £125.00 mount directly on most buffered. Will directly offset satellite dishes. drive TTL/CMOS or 0.8db NF. 9.0GHz LO. relays directly. Can be £40.00 used to control whatever your imagination thinks of. £12.00 All kits contain all board mounted components and full comprehensive instructions. Prices are all inclusive of P&P etc. PCB’s are available assembled and tested at extra charge. SAE. (to take A4 paper) for further details. Orders etc. to Bob Platts G8OZP, 220 Rolleston Road, Burton Upon Trent, Staffs, DE13 0AY. Phone 01283 531443, 7-9pm on weekdays only please. 1997 by the BATC CQ-TV 177 Page 5 3cm Signal Strength Meter 3cm Signal Strength Meter By Barry Keedy G6LIC A cheap, simple but effective signal strength meter for 3 centimetres can be constructed and cased