Fullscreen HTML5Med Res (??MB)HTML4

PRODUCT SHOWCASE Metex M-3850 digital multimeter has PC interface As well as all the common features you would normally expect to find on a current auto-ranging digital multimeter, this Metex M-3850 has frequency, capacitance & temperature measurement, transistor testing, dual display & the ability to store data for later analysis. The M-3850 has a large back-lit dual liquid crystal display. The main display is a 4000 count array with 15mm high digits and it is supplemented with a smaller 4000 count display in the top right-hand corner. Small icons show the current operating mode while a bargraph provides analog in­dication of the measurement. Press­ ing the function button scrolls through the various modes. The secondary display can be used as a data hold facility, to keep account of a measured maximum, minimum or a value relative to a preset value, while the main display shows the cur­rent reading. In dual mode, it allows two measurements to be displayed at once. For instance, the primary dis­play can show a DC supply voltage while the other displays the frequency of the ripple on the supply, or the temperature can be displayed in Cel­sius on the main display and Fahren­heit on the secondary display. As with most DMMs, there are separate terminals for the current ranges which are used in conjunction with the large rotary selector switch, the milliamp terminal is used for current measurements on the 40mA and 400mA ranges while the Amp terminal is used for measurements up to 20A (one range only). The meter can be set to measure AC or DC using the DCW/ AC button. For voltage measurements, the CALLING ALL HOBBYISTS We provide the challenge and money for you to design and build as many simple, useful, economical and original kit sets as possible. We will only consider kits using lots of ICs and transistors. If you need assistance in getting samples and technical specifications while building your kits, let us know. YUGA ENTERPRISE 705 SIMS DRIVE #03-09 SHUN LI INDUSTRIAL COMPLEX SINGAPORE 1438 TEL: 65 741 0300    Fax: 65 749 1048 August 1994  87 Hakko 926 soldering station The Hakko 926 is a deluxe sol­dering station builffor production work or for use by service techni­ cians and enthusiasts. It has a 50 watt ceramic element and a hold­ing temperature accuracy of ±0.5C. Tip temperature can be varied from 200-480°C. The iron is well balanced and has a rubberised grip, while the cord is burn-proof silicone and has strain relief at both ends. The 5-pin connector has a locking ring to prevent accidental disconnection. The station has a heavy base and is fully electronically controlled via the temperature knob on the front panel. A LED indicates that the iron is heating. The stainless steel sponge tray is removable and has an excess solder tray that overhangs for easy solder collection. The unit comes with a 3-pin plug and the tip is grounded for ESD protection. A 1.6mm conical tip is K ALEX The UV People ETCH TANKS ● Bubble Etch ● Circulating LIGHT BOXES ● Portuvee 4 ● Portuvee 6 ● Dual Level TRIMMER ● Ideal PCB DRILL ● Toyo HiSpeed MATERIALS ● PC Board: Riston, Dynachem ● 3M Label/Panel Stock ● Dynamark: Metal, Plastic ✸ AUSTRALIA’S NO.1 STOCKIST ✸ K ALEX 40 Wallis Ave, East Ivanhoe 3079. Phone (03) 9497 3422, Fax (03) 9499 2381 88  Silicon Chip supplied but many other styles are available. The manual is comprehensive and states the specifica­tion and calibration adjustments for all possible tips. A “CAL” trim­pot on the base of the unit is used for this purpose. The holster has been designed to be placed on either side of the station for ease of use and is an­gled by loosening off the adjust­ment screw. The Hakko 926 soldering sta­tion sells for $259 and is available from all Dick Smith Electronics stores and resellers. ranges run in the following sequence: 400mV, 4V, 40V, 400V and a maxi­mum of 1000V DC or 750VAC. The meter is fully autoranging but has the facility to lock onto a single range when needed. This is done by selecting the R-H (Range Hold) mode and then stepping through the ranges using the Up or Down button. When it comes to measuring frequency, the Metex M-3850 really shines. Most DMMs that measure frequency are hard put to measure up to 1MHz but this unit can go to 40MHz. Input sensitivity is quoted as better than 100mV RMS for frequencies up to 30MHz to over 300mV for frequen­cies above 30MHz. It has good capaci­tance ranges too: 4nF, 40nF, 400nF, 4µF, 40µF and 400µF (1nF = .001µF). The resistance ranges run as follows: 400W, 4kW, 40kW, 400kW, 4MW and 40MW. The meter provides an audible continuity alarm for resistances below 30W and the diode test range will light most LEDs. Maximum open circuit voltage for the diode test is 2.5V. Another good feature of the Metex is the auto-off switch. It turns the me­ter off if none of the pushbuttons or the selector switch has been touched for 10 minutes. Without this feature, most DMMs become battery eaters and that becomes frustrating when the bat­tery dies just as you are about to take a crucial measurement. For transistor hFE measurements, the maximum reading is 4000 which will allow the Metex to measure many Darlington transistors. However, the instruction manual warns that some Darlingtons have internal resistors (be­tween base and emitter) and these can give rise to misleading results. An interesting mode is the ‘Comparison’ function. The icon ‘CMP’ ap­pears on the display and the meter uses two memo·ries as high.and low to test the current reading against and displays ‘Hi’, ‘Low’ or ‘Pass’ depending on the value. All told, the Metex has 10 memories for storing data and these can be stepped through using the Function button. Datalogging Where the Metex is outstanding is in its ability to be transformed into a datalogger. It can be connected to a PC or compatible with an optional serial interface which is accompanied with software. This enables measurements to be stored away with time stamping. Values can be graphed either in real time or replayed later. The software is mouse driven and has pull-down menus. Two serial ports are therefore needed to get the software running, one for the mouse and another for the meter. Collected data can be viewed in three modes: a line graph that autoranges its Y axis (as the meter does); a time-stamped history of collected values; and a large mim­icked display of the meter itself. Col­lected values are stored in ASCII files that can be replayed by the software or loaded into other software for fur­ther analysis. All told, the Metex M-3850 digital multimeter is an attractive package with lots of features. It is supplied in a vinyl case with separate sections to store the meter and test leads. Recommended retail price is $229.50 while the computer interface and software is a further $18.95. Other options in­ clude a rubber holster and an external temperature probe. For more information on the Metex M-3850, contact your local Jaycar Elec­ tronics store or reseller. Phone (02) 743 5222. Celestion SRA series power amplifiers Celestion’s new SRA series power amplifiers feature the com­ pany’s dual rail soft-switch output stage, employing linear, output­derived class G amplification. The soft-switch design means that the switch to the upper rail is inaudi­ble. It provides the advantages of dual rail operation, with a big in­crease in efficiency and a corre­ sponding reduction in the genera­ tion of heat, without the distortion generated by fast-attack rail switch­ing. Built to survive the rigours of touring, all SRA series amplifiers feature a heavy-gauge steel chassis coupled to a transverse heatsink to add rigidity. A continuously vari­able cooling fan temperature con­ trolled from the heatsink is an­other feature. Heavy duty output relays are employed to protect the loudspeaker load and a logic-con- trolled power-up sequence enables the outputs only when the amplifier has settled. Outputs are continu­ously monitored and are disabled in the event of operation outside specified tolerances. Output pro­tection status is provided on the front panel. All operational controls, the fan, filter and tamper-proof bridging and ground lift switches are acces­sible from the front panel, without the need to remove the amplifier from its rack. The rear panel has provision for a variety of New range of low-cost snap-fitting cases This new line of poly­s tyrol cases all have moulded pillars for mounting PC boards The larger cases all have ventilation slots and separate plastic front and rear panels Sizes available are 207 x 68 x 179mm, 151 x 58 x 139mm and 94 x 47 x 134mm (W x H x D). The smaller cases in the range do not have separate front and rear panels but have moulded slots, as well as pillars for PC board mounting. There are two different sized case halves and these may be mixed and matched to build cases of three different heights. The half case sizes are 71 x 24 x 123mm and 71 x 15 x 123mm (W x H x D). A baby case is also available but is not snap-fitting and is sized 70 x 47 x 40mm. All cases are available in black and a grey-white. For more information on these cases, contact Anton’s Trains, Cnr Prince & Mary St, North Parramatta, NSW 2151. Phone (02) 683 3858. mating connectors, including parallel latching XLRs for daisy-chaining, heavy duty binding posts and Neutrik Speakon connectors. Presently, two SRA models are available: (1) the SRA1000 with 510 watts into 4-ohms or 1020 watts bridged into 8-ohms; and (2) the SRA1600 with 815 watts into 4-ohms or 1620 watts bridged into 8-ohms. For further information contact Amber Technology Pty Ltd, Unit B, 5 Skyline Place, Frenchs Forest, NSW 2086. Phone (02) 975 1211 or fax (02) 975 1368. PC COMPUTERS (08) 364 0902 (08) 332 6513 36 Regent St, Kensington, South Australia High Power 2.5 Watt Transmitter Kit FMTX1 $69 This kit uses a single transistor to provide up to 2.5 watts into a 50-ohm load. It can be set on the FM band from 88-108MHz. Audio is 500mV P-P with Australian pre-emphasis. Power supply from 12-24 volts DC. Range up to 100 miles. Leaky coax distribution can be used with any of our transmitters, terminate up to 2km of coax with a 50-ohm resistor and no radiation occurs. Use a 150-ohm WW pot and you can set the level of radiation up to 300 metres from the coax. You can use this method to comply with DOTC schedule 3. XTAL Locked 30mW Transmitter (The best quality kit transmitter in Australia) FMTX2B $49 This transmitter is XTAL-locked on 100MHz (XTAL supplied) and is the most stable kit transmitter on the market. It features a 3-stage design with only two tuned circuits and a clean output. This design can be used as the basis of a station exciter. Digital Stereo Coder (All Digital Design With Australian Pre-emphasis) FMTX2A $49 This is a universal stereo coder able to be used with all of our transmitter designs and many others. Its performance is superior to domestic encoder single chip designs. Dozens have been sold to FM stations as a standby stereo coder or with the FMTX2B as an exciter. Both FMTX2A and FMTX2B on 1 PCB as a complete stereo transmit­ter FMTX5 $99 MAX I/O Board for PCs (Talk To The Outside World) $169 This kit features 7 relays, ADC, DAC, stepper motor driver with sample software in Basic and connects to a PC’s parallel port. Now also available I/O bits software for MS Windows so you can program functions without being a programmer. Call relays by a name like stop relay, assign its own icon - uses a simple VISUAL interface to make your own PLC. Full developer’s version has DOS runtime so you do not require Windows and optional sup­port for LCD displays. Data logging ADC and DAC boards and more. MAX version $169. FM Band Linear Amplifier Kits (All Imported Kits) New 30mW to 1 watt linear coming in September 1994 (advance orders taken) 500mW to 5 or 10 watts $199 250mW to 25 watts 15 watts to 110 watts $599 40 watts to 300 watts Power supplies and heatsinks not included in short form kit price. $99 $249 $999 Other kits available. Call for a list or see Silicon Chip April-June 1994 or the Silicon Chip Model Railway Book. August 1994  89