Silicon ChipMarket Centre - September 1991 SILICON CHIP
  1. Outer Front Cover
  2. Contents
  3. Publisher's Letter: The future of electronic mail
  4. Feature: The Highs & Lows Of A/D & D/A Conversion by Darren Yates
  5. Feature: Plotting The Course Of Thunderstorms by Leo Simpson
  6. Project: Studio 3-55L 3-Way Loudspeaker System by Greg Swain
  7. Project: Digital Altimeter For Gliders & Ultralights, Pt.1 by John Clarke
  8. Serviceman's Log: I'd never seen that one before by The TV Serviceman
  9. Subscriptions
  10. Order Form
  11. Project: Build A Fax/Modem For Your Computer by Leo Simpson
  12. Feature: Computer Bits by Jennifer Bonnitcha
  13. Project: Ultrasonic Switch For Mains Appliances by Jeff Monegal
  14. Feature: Amateur Radio by Garry Cratt, VK2YBX
  15. Vintage Radio: Transistor radios are worth collecting by John Hill
  16. Back Issues
  17. Feature: The Story Of Electrical Energy; Pt.13 by Bryan Maher
  18. Market Centre
  19. Advertising Index
  20. Outer Back Cover

This is only a preview of the September 1991 issue of Silicon Chip.

You can view 44 of the 96 pages in the full issue, including the advertisments.

For full access, purchase the issue for $10.00 or subscribe for access to the latest issues.

Articles in this series:
  • Digital Altimeter For Gliders & Ultralights, Pt.1 (September 1991)
  • Digital Altimeter For Gliders & Ultralights, Pt.2 (October 1991)
  • Digital Altimeter For Gliders & Ultralights, Pt.3 (November 1991)
Articles in this series:
  • Computer Bits (July 1989)
  • Computer Bits (August 1989)
  • Computer Bits (September 1989)
  • Computer Bits (October 1989)
  • Computer Bits (November 1989)
  • Computer Bits (January 1990)
  • Computer Bits (April 1990)
  • Computer Bits (October 1990)
  • Computer Bits (November 1990)
  • Computer Bits (December 1990)
  • Computer Bits (January 1991)
  • Computer Bits (February 1991)
  • Computer Bits (March 1991)
  • Computer Bits (April 1991)
  • Computer Bits (May 1991)
  • Computer Bits (June 1991)
  • Computer Bits (July 1991)
  • Computer Bits (August 1991)
  • Computer Bits (September 1991)
  • Computer Bits (October 1991)
  • Computer Bits (November 1991)
  • Computer Bits (December 1991)
  • Computer Bits (January 1992)
  • Computer Bits (February 1992)
  • Computer Bits (March 1992)
  • Computer Bits (May 1992)
  • Computer Bits (June 1992)
  • Computer Bits (July 1992)
  • Computer Bits (September 1992)
  • Computer Bits (October 1992)
  • Computer Bits (November 1992)
  • Computer Bits (December 1992)
  • Computer Bits (February 1993)
  • Computer Bits (April 1993)
  • Computer Bits (May 1993)
  • Computer Bits (June 1993)
  • Computer Bits (October 1993)
  • Computer Bits (March 1994)
  • Computer Bits (May 1994)
  • Computer Bits (June 1994)
  • Computer Bits (July 1994)
  • Computer Bits (October 1994)
  • Computer Bits (November 1994)
  • Computer Bits (December 1994)
  • Computer Bits (January 1995)
  • Computer Bits (February 1995)
  • Computer Bits (March 1995)
  • Computer Bits (April 1995)
  • CMOS Memory Settings - What To Do When The Battery Goes Flat (May 1995)
  • Computer Bits (July 1995)
  • Computer Bits (September 1995)
  • Computer Bits: Connecting To The Internet With WIndows 95 (October 1995)
  • Computer Bits (December 1995)
  • Computer Bits (January 1996)
  • Computer Bits (February 1996)
  • Computer Bits (March 1996)
  • Computer Bits (May 1996)
  • Computer Bits (June 1996)
  • Computer Bits (July 1996)
  • Computer Bits (August 1996)
  • Computer Bits (January 1997)
  • Computer Bits (April 1997)
  • Windows 95: The Hardware That's Required (May 1997)
  • Turning Up Your Hard Disc Drive (June 1997)
  • Computer Bits (July 1997)
  • Computer Bits: The Ins & Outs Of Sound Cards (August 1997)
  • Computer Bits (September 1997)
  • Computer Bits (October 1997)
  • Computer Bits (November 1997)
  • Computer Bits (April 1998)
  • Computer Bits (June 1998)
  • Computer Bits (July 1998)
  • Computer Bits (November 1998)
  • Computer Bits (December 1998)
  • Control Your World Using Linux (July 2011)
Articles in this series:
  • Amateur Radio (November 1987)
  • Amateur Radio (December 1987)
  • Amateur Radio (February 1988)
  • Amateur Radio (March 1988)
  • Amateur Radio (April 1988)
  • Amateur Radio (May 1988)
  • Amateur Radio (June 1988)
  • Amateur Radio (July 1988)
  • Amateur Radio (August 1988)
  • Amateur Radio (September 1988)
  • Amateur Radio (October 1988)
  • Amateur Radio (November 1988)
  • Amateur Radio (December 1988)
  • Amateur Radio (January 1989)
  • Amateur Radio (April 1989)
  • Amateur Radio (May 1989)
  • Amateur Radio (June 1989)
  • Amateur Radio (July 1989)
  • Amateur Radio (August 1989)
  • Amateur Radio (September 1989)
  • Amateur Radio (October 1989)
  • Amateur Radio (November 1989)
  • Amateur Radio (December 1989)
  • Amateur Radio (February 1990)
  • Amateur Radio (March 1990)
  • Amateur Radio (April 1990)
  • Amateur Radio (May 1990)
  • Amateur Radio (June 1990)
  • Amateur Radio (July 1990)
  • The "Tube" vs. The Microchip (August 1990)
  • Amateur Radio (September 1990)
  • Amateur Radio (October 1990)
  • Amateur Radio (November 1990)
  • Amateur Radio (December 1990)
  • Amateur Radio (January 1991)
  • Amateur Radio (February 1991)
  • Amateur Radio (March 1991)
  • Amateur Radio (April 1991)
  • Amateur Radio (May 1991)
  • Amateur Radio (June 1991)
  • Amateur Radio (July 1991)
  • Amateur Radio (August 1991)
  • Amateur Radio (September 1991)
  • Amateur Radio (October 1991)
  • Amateur Radio (November 1991)
  • Amateur Radio (January 1992)
  • Amateur Radio (February 1992)
  • Amateur Radio (March 1992)
  • Amateur Radio (July 1992)
  • Amateur Radio (August 1992)
  • Amateur Radio (September 1992)
  • Amateur Radio (October 1992)
  • Amateur Radio (November 1992)
  • Amateur Radio (January 1993)
  • Amateur Radio (March 1993)
  • Amateur Radio (May 1993)
  • Amateur Radio (June 1993)
  • Amateur Radio (July 1993)
  • Amateur Radio (August 1993)
  • Amateur Radio (September 1993)
  • Amateur Radio (October 1993)
  • Amateur Radio (December 1993)
  • Amateur Radio (February 1994)
  • Amateur Radio (March 1994)
  • Amateur Radio (May 1994)
  • Amateur Radio (June 1994)
  • Amateur Radio (September 1994)
  • Amateur Radio (December 1994)
  • Amateur Radio (January 1995)
  • CB Radio Can Now Transmit Data (March 2001)
  • What's On Offer In "Walkie Talkies" (March 2001)
  • Stressless Wireless (October 2004)
  • “Degen” Synthesised HF Communications Receiver (January 2007)
  • WiNRADiO: Marrying A Radio Receiver To A PC (January 2007)
  • PICAXE-08M 433MHz Data Transceiver (October 2008)
  • Half-Duplex With HopeRF’s HM-TR UHF Transceivers (April 2009)
  • Dorji 433MHz Wireless Data Modules (January 2012)
Articles in this series:
  • The Technology Letters, Pt.2 (January 1989)
  • The Story Of Electrical Energy (July 1990)
  • The Story Of Electrical Energy; Pt.2 (August 1990)
  • The Story Of Electrical Energy; Pt.3 (September 1990)
  • The Story Of Electrical Energy; Pt.4 (October 1990)
  • The Story Of Electrical Energy; Pt.5 (November 1990)
  • The Story Of Electrical Energy; Pt.6 (December 1990)
  • The Story Of Electrical Energy; Pt.7 (January 1991)
  • The Story Of Electrical Energy; Pt.8 (February 1991)
  • The Story Of Electrical Energy; Pt.9 (March 1991)
  • The Story Of Electrical Energy; Pt.10 (May 1991)
  • The Story Of Electrical Energy; Pt.11 (July 1991)
  • The Story Of Electrical Energy; Pt.12 (August 1991)
  • The Story Of Electrical Energy; Pt.13 (September 1991)
  • The Story Of Electrical Energy; Pt.14 (October 1991)
  • The Story Of Electrical Energy; Pt.15 (November 1991)
  • The Story Of Electrical Energy; Pt.16 (December 1991)
  • The Story Of Electrical Energy; Pt.17 (January 1992)
  • The Story Of Electrical Energy; Pt.18 (March 1992)
  • The Story Of Electrical Energy; Pt.19 (August 1992)
  • The Story of Electrical Energy; Pt.20 (September 1992)
  • The Story Of Electrical Energy; Pt.21 (November 1992)
  • The Story Of Electrical Energy; Pt.22 (January 1993)
  • The Story of Electrical Energy (April 1993)
  • The Story Of Electrical Energy; Pt.24 (May 1993)
  • The Story Of Electrical Energy; Pt.24 (June 1993)
MARKET CENTRE Cash in your surplus gear. Advertise it here in Silicon Chip. FOR SALE WEATHER FAX programs for IBM XT/ ATs *** "RADFAX2" is a high resolution, shortwave weather fax, Morse & RTTY receiving program. Need& CGA, SSB HF radio & Radfax decoder. Also "RF2HERC", "RF2EGA" & "RF2VGA", same as RADFAX2 but suitable for Hercules, EGA & VGA cards respec tively. $35. *** "SATFAX" is a NOAA, Meteor & GMS weather satellite picture receiving program. Uses EGA & VGA modes, needs EGA or VGA colour monitor & card, plus "WEATHER FAX" PC card. $45. ••• All programs are on 5.25-inch or 3.5-inch discs (state which) & include documentation. Add $3 postage. Only from M. Delahunty, 42 Villiers St, New Farm, 4004 Old. Phone (07) 358 2785. 0 MY AUSTRALIAN DESIGNED lowcost super fast Z80 micro-controller development system has gained acceptance already with educational institutions. Pop it on the end of any PC MS-DOS or Z80 machine & away you go. Boards, EPROM & 360Kb disc $76 including postage for a short form kit. Gee, I wish I had this when I was a kid. For more information send a 43c stamp to Don McKenzie, 29 Ellesmere Crescent, Tullamarine 3043. IBM COMPATIBLE computer kits & accessories. Button spike protector $37.00. 6-socket power boards with surge/spike protection $49.00. Pack/ post $3.00. Send for a free price list. M.T.S. Electronics, PO Box 1013 Taree, NSW 2430. Phone (065) 53 1296. PC VOICE RECORDER SOFTWARE. Project published in SILICON CHIP, August 1991. Plugs into the printer board of any genuine IBM PC/XT/AT/ 386 or compatible. Record up to 20 seconds of sound, save it to disc & replay it in the future. Software only available on 5.25-inch 360Kb disc plus documentation & instructions for $25 plus $3. Talking Clock software also available - turns your computer into a talking timepiece. $15 plus $3 p&p. r-------------------------7 CLASSIFIED ADVERTISING RATES Advertising rates for this page: Classified ads - $7.00 for up to 15 words plus 40 cents for each additional word. Display ads (casual rate) - $20 per column centimetre (Max. 10cm). Closing date: five weeks prior to month of sale. To run your classified ad, print it clearly on a separate sheet of paper & send it with this form & your cheque or credit card details to : Silicon Chip Classifieds, PO Box 139, Collaroy Beach, NSW '2097. Or fax the details to (02) 979 6503. Enclosed is my cheque/money order for $_ _ _ _ or please debit my O Bankcard O Visa Card 0 Master Card I I I I I I I I I iI I I Signature_ _ _ _ _ _ _ _ _ _ _ Card expiry date_ _~/_ __ I I Name _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ __ I I Street _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ __ I I Suburb/town _ _ _ _ _ _ _ _ _ _ _ _ Postcode_ _ _ _ __ L _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ JI Card No. (VGA, EGA, CGA, Mono). Send cheque or money order to Darren Yates, PO Box 134, French's Forest, NSW 2086. PROFESSIONAL KITS & products. Amplifiers, power supplies, test equipment, PC driven devices & surplus parts. Send SASE for list to: Al Younger, 5/22 Albert St, Edgecliff, NSW 2027. ULTRASONIC BURGLAR Alarm Kit. See S.C. May 1988. Crystal locked. Can be used as a detector or as a selfstanding alarm. Provision for bonnet/ boot protection, flashing light & backup battery. Easily combined with our UHF remote control. Save 100s of dollars on equivalent commercial alarms. Clearance priced at only $29.90 for the PCB and all parts, except the screw terminals. A pair of ultrasonic transducers is included! Don't miss out. P&P for any one or more kits listed: $5. Oatley Electronics, PO Box 89, Oatley, 2223. Phone (02) 579 4985. SINGLE CHANNEL UHF Remote Control. EA Jan.89 & April 89. Use it to switch car alarms, central locking, activate door openers, etc. Up to 50-metre range. Has separate switch & indicator relays. More than 19,000 code combinations. Features a compact transmitter. Only $49.95 for a complete transmitter kit & the receiver PCB and all on-board components. Extra transmitters are priced at $17 each. P&P for any one or more kits listed: $5. Oatley Electronics, PO Box 89, Oatley, 2223. Phone (02) 579 4985. LASER ASSEMBLY. Not a kit but a complete commercial HeNe visible red laser contained in a small plastic case. Dimensions 160 x 60 x 35mm . 7-14V DC operation at approx. 300mA. Includes a brand new 1mW tube. Very limited quantity at $135 each. P&P $5. Oatley Electronics, PO Box 89, Oatley, 2223. Phone (02) 579 4985. LOW-COST PIR Movement Detector Alarm. EA, May 1989. Now supplied with commercial case. Reliable unit that features a dual element pyroelectric SEPTEMBER 1991 95 ...._ r MEMORY EXPANSION Advertising Index Prices at July 10th 1991 DRAM DIP. ZIP SIMM & SIP SPEED (ns) TYPE 120 100 70 80 4164 2.20 2.35 41256 1.80 2.00 2.20 2.40 41464 2.50 2.75 411000 6.10 7.30 7.90 1MBx4 (Static) 36.00 256K x 9 14.00 20.00 21.00 1MBx9 58.00 68.00 78 .00 4MB x 9 272 .00 299 .00 Simm Sockets 30 x 1 Vertical 1.70 Simm Sockets 30 x 2 Angle 3.50 Simm Sockets 30 x 2 Vertical 3.20 PELHAM \.. INTEL 8087 (fits all 8088's) 80287-10 ' 80287-XLT (laptops) 80287-XL (up to 20MHz) 387SX16 387SX20 387DX16 387DX20 387DX25 387DX33 387DX40 Antique Radio Restorations ....... 96 Av-Comm ... ............ .. .. .... .. ......... . 33 120.00 125.00 160.00 150.00 180.00 188.00 185.00 265.00 265.00 300.00 350.00 Back Issues .......................... 86,87 David Reid Electronics ...... ... IFC, 1 Dick Smith Electronics .... ..... ... 9-11 Electronic Solutions ............. ... ... 69 Electronic Toy Services ...... ....... 96 Elmeasco ... ......................... ....... 77 Geoff Wood Electronics ............. 35 Sales Tax 20%. Overnight Delivery. Credit Cards Welcome 1st Floor, 100 Yarrara Road, Pennant Hills, NSW 2120 . Tel (02) 980 6988 PRINTED CIRCUIT BOARDS Altronics ................................ 24-27 CO-PROCESSORS CYRIX IIT Fax (02) 980 6991 Harbuch Electronics .................. 57 Hycal Instruments ...... ...... .... ...... 96 Jaycar Electronics ................ 45-52 .J FIX-A-KIT $20.00 PER HOUR LABOUR PCBs for all SILICON CHIP projects made to order. Prototype & kit repair service available. Hours 10-5 Wednesday to Friday, 9-12 Saturday. ETS, PO BOX 491, NOARLUNGA CENTRE, SA 5168. Phone: (08) 382 8919 MAX 1/0 Board Kit $149.00. Built & Tested $269.00. • 7 x Relays SPST 2 amps each • 8 x Switch inputs (TTL) • 1 x OAC (Digital to Analog converter) • 1 x ADC ( Analog to Digital converter) • 4 x Motor Drive outputs (40mA ea.) • 1 x Programmable timer output. MAX includes a 20-page manual with all schematics, parts layout etc., a 360K PC-compatible floppy with diagnostic and sample software in GW-Basic. MAX runs from a PC compatible printer port for full compatibility with a large range of computers. Same day dispatch of orders. Credit cards or personal cheques welcome. Phone (08) 332 6513 or Fax (08) 364 0902 (24 hours) PC Computers, 36 Regent St, Kensington, SA. sensor. Optional interface kit enables uses such as self-standing alarms, automatic light control, shop entry detector, etc. Over 1O metres range. Don't miss out at the clearance price of only $29.90 for the PCB & the PIR detector components kit. Interface components kit $9.00. P&P $5. Oatley Electronics, PO Box 89, Oatley, 2223. Phone (02) 579 4985. ANTIQUE RADIO ANTIQUE RADIO restorations. Your one-stop radio repair shop. Specialising in restoring vintage radios including 96 SILICON CHIP J.V. Tuners .... .... .. ....... ...... .. ........ 43 Oatley Electronics .. .... ............... 79 PC Computers .... ..... .................. 96 3 MONTHS WARRANTY ON REPAIRS 12 MONTHS WARRANTY ON CONSTRUCTION PC Marketplace ............ ............. 81 Service to most types of electronic equipment TECHNICAL ASSISTANCE Pelham ... .. ........ ......................... 96 HYCAL ELECTRONICS Design. Manufacture & Repair of Electronic Equipment Trading Hours 8am to 3pm, Monday to Friday (02) 633 5477 Philips Test & Measurement .. OBC RCS Radio .. .. ... ..... .. .. ................ 43 Resurrection Radio .................. .. 85 Rod Irving Electronics .......... 38,39 Silicon Chip Binders ................ IBC Stewart Electronics .................... 85 TRANSFORMER REWINDS ALL TYPES OF TRANSFORMER REWINDS TRANSFORMER REWINDS Reply Paid No.2, PO Box 438, Singleton, NSW 2330. Ph: (065) 761291. Fax: (065) 761003. Subscriptions .... ... ...... ........... 53,54 TopCom Radio Comm . .............. 96 Transformer Rewinds ................ 96 PC Boards Printed circuit boards for SILICON CHIP projects are made by: SCANNERS • Electronic Toy Services, 2/111 Glynville Drive, Hackham West, SA 5163. Phone (08) 382 8919. Top quality Uniden, factory authorised dealer. Range from $210.05 for 50XL, covers 10, 6, 2, 70cm , 10 memories, ideal for amateur, to $475.52 for 200XLT, 200ch , covers all major bands, including 800-900MHz. Also the cheapest prices on marine equipment. Update to SSB for $238.26. Fibreglass 27MHz antenna $40.1 3. Post & pack $1 0 under $250. Cash, cheque & credit card accepted . TopCom Radio Communication, PO Box 336, Greensborough, Vic 3088. Phone (03) 883 9535. • RCS Radio Pty Ltd, 651 Forest Rd, Bexley, NSW 2207. Phone (02) 587 3491. chassis rewiring, re-condensing, quality new parts, valves, valve sockets, speakers, power & audio transformers. Secondhand radio dials & parts for most brands & models. About 400 radios in stock for sale, restoration & parts, Every restored wireless is covered by a 2year warranty on parts & labour. We restore damaged woodwork & cabinets & French polish (approx. 40 coats). Vintage car radios available for sale or restoration. Repairs done on tape decks & amplifiers. Open Sat. 1 Oam-5pm; Sun. 12.30-5pm . 109 Cann St, Bass Hill, NSW 2197. Phone (02) 645 3173 BH or (02) 726 1613 AH. SC • Jemal Products, 5 Forge St, Welshpool , WA 6106. Phone (09) 350 5555. • Marday Services, PO Box 19-189, Avondale, Auckland, NZ. Phone 88 5730.