Fullscreen HTML5Med Res (??MB)HTML4

HoARDING: urban Electronic Archaeology Don’t let this happen to you! If you have a large collection of anything (including electronics), you must have a succession plan. It would also be a good idea for you to periodically ‘clean house’ and allow collectors – young and old – to pick up items you don’t absolutely need. I recently had the task of sorting through an extensive might be). He had told me that he usually paid $2-5 each collection of electronic items which were part of a defor these at the weekend markets. ceased estate. As I had been a long-time friend of the 2) Huge numbers of CDs and floppy disks, mostly for comdeceased, I was permitted to ‘rescue’ any interesting items puter games, likely never used. I found, as they would otherwise end up in a landfill. 3) Many car parts, mostly incomplete or used, mostly There were a vast number of items in the hoard, but Holden-related and including at least two ‘grey motors’ before I had a chance to go through it, drug addicts and and one ‘red motor’. other thieves were reported to have broken in and taken 4) Lots of scrap metal. anything that could be sold on the street. 5) Numerous pieces of electronic or mechanical equipWhat remained (see opposite for an example) was of ment, usually incomplete or broken, in various states of little-to-no monetary value, but still of interest to elecdisassembly with components missing or, in the case of tronic enthusiasts. In fact, by taking items away, I was many electrical or electronic items, with the power cords probably saving the estate the cost of disposing of them. cut off. This is likely because it is illegal in Victoria to The collection was accumulated over a lifetime, mostly sell electrical items without an electrical safety test, and being purchased from second-hand markets, one being the for the low value of many items, that is not worthwhile. well-known Laverton Market in Leakes Rd, Laverton, Vic. 6) Many broken items, as items covered the floor nearly Many of the other items seem to have been discarded everywhere. Apart from a few ‘goat tracks’ with limited by industrial or government laboratories. visibility of the floor, mostly one had to walk on these Most of the items were filthy, with 50 or so years of items to move around the house. If they weren’t broken accumulated dust and grime, plus damage from being when acquired, they soon would be. (Some rooms were thrown into a heap rather than stacked correctly. To get unreachable due to items stacked floor to ceiling). the items shown here into presentable condition required The full extent and composition of the hoard is not known extensive cleaning at the time of writing, because what was recovered and preUnlike some hoards, I did not find much actual rubsented here is only what was obvious and at the surface bish, just a lot of ‘stuff’ in several general categories: level. In many areas, the hoard was a metre or more thick. 1) A staggering number of generic desktop PCs. These A variety of older electronic items I found were handwere mostly from the 1990s and 2000s, made for various scientific or technical and not collectible computers (such as purposes. Back in the day, it was common original IBM, Apple or Commodore PCs By Dr David Maddison for large government, university and com10 Silicon Chip Australia’s electronics magazine siliconchip.com.au mercial laboratories to make their own equipment as it wasn’t always commercially available, or it would take too long to order it from overseas. The items I recovered represent an interesting cross-section of electronics for virtually the whole of the twentieth century. The collection of articles presented here also includes items he gave me while he was alive. Where I found multiple similar items, I will show the Australian-made item if there is one. Postscript Although my friend was known by work colleagues to be brilliant, when he passed away, there were no funeral arrangements. So besides showing some interesting items, this article also serves as something of a memorial or tribute to his life. Appropriately for a collector of elec- Just a small part of what I was faced with . . . after drug addicts and thieves had tronics, his initials were A. C. already gone through it. Vintage Gallenkamp switchboard ammeter (1910s) I found this Gallenkamp ammeter, estimated to be made around 1910, based on a very similar one I found in a catalog (see below). It was found halfimmersed in water. Philips valve radio ‘battery eliminator’ (1920s) Valve radio batteries were expensive. These devices replaced two of the three battery types (the “B” and “C” batteries) with a mains supply. The technology at that time made it difficult to eliminate the “A” battery. The one I found is a Philips 3003, made in Holland and very popular in Australia. It appears that somebody tried to repair it as many wires were disconnected. For more information on this device, including a circuit diagram, see www.tuberadio. com/robinson/museum/ Philips_3003/ siliconchip.com.au Ormond variable condenser (capacitor) (1920s) This was in a pile of rubbish, but it caught my attention because it had screw terminals. I measured its maximum capacitance as 450pF and determined it to be from the UK brand Ormond, and almost certainly the No. 3 model. It featured “S.L.F.” or “straight-line frequency”. This meant that through the rotation of the dial, the corresponding frequencies would be linearly proportional to the dial position. According to Radio Retailing magazine of December 1925, this “improves the tuning of a set and has been developed to meet conditions which were becoming almost intolerable, namely, the crowding of the stations in the lower part of the present broadcast range”. Headphone and headphone parts (1920s to 1940s) The oldest such item I found was made by Brandes Ltd, London, and marked “superior matched tone”. It is one driver from a pair of headphones. According to radiomuseum.org, this item dates from approximately 1924-1932. It is marked “BBC” (probably not the broadcaster) and “Made in England”. Its nominal impedance is 1000. I also found a Brunet & Cie driver from their Casques et Écouteurs Type F model, dated around 1924 (according to radiomuseum. org). It was available with an impedance of either 500 or 2000. Another was a complete set of Australianmade Q-Plus brand headphones. I could not find any information online about them, but Q-Plus was an Australian manufacturer operating from 1947 to at least 1965. Australia’s electronics magazine March 2021  11 Astor radio dial (1930s?) This dial is from an Astor Super Six. I found one such radio for sale which described it as being from the 1930s. It incorporated an English-made turntable into a (presumably) Australian-made AM radio. Smashed or incomplete valve radio chassis (1940s and 1950s) There were several valve radio chassis without enclosures, all incomplete and/or damaged, as was typical of most items in the hoard. I passed these on to collectors for spare parts, as they were beyond any hope of restoration. Many of the chassis were corroded, meaning that their transformers were probably also internally corroded and thus unusable. Vintage panel meters (1940s to 1970s) I found a variety of vintage panel meters. Here are a few that were Australianmade (top row) as well as some from the UK, USA and Japan. Except for the one by Ernest Turner Electrical Instruments Ltd, I could find no information to date these accurately, so I had to make educated guesses based on their styles. Philips model 164 radio (1955) This radio is Australian-made. It was a rare example of a radio from the hoard in a semicomplete condition – except that Vintage fluorescent light starter (1950s) This unusual fluorescent starter is a General Electric (USA) FS-850 “Watch Dog” model. According to the GE “Catalog of Large Lamps” from 1956, “Watch Dog starters provide automatic cut-off at the end of lamp life. This eliminates blinking and protects the ballast. When a new lamp is installed, a touch of the manual reset button makes the starter operative again.” Flashing fluorescent lights used to be a common and annoying problem, and failing tubes could lead to ballast damage. It’s a pity this design wasn’t more widely adopted.     Australian-made toggle switch   (1950s?) This Australian-made threeposition toggle switch of open construction is marked “0.5A 250 V.A.C. Only” and “G.W. Engineering P/L Sydney Australia”, and was probably made for a radio. This shows the diversity of Australian electronic manufacture before 1972. Admiral 5AW valve radio (1950s) This was one of the first, if not the first, valve radio made in Australia (and worldwide!) with a printed circuit board (PCB). This model was released in 1956, and we published an article on it in May 2019 (siliconchip.com.au/Article/11633). It came with an optional clock; in this case, the clock was not fitted. I gave this to a collector for parts. Mains timer (1950s?) The electromechanical device shown at left counts to 55 minutes and 59 seconds before switching off a mains-powered device. It is unbranded, but powered by a Warren Telechron someone has put the dial on upside down! For more on this radio, go to www.radiomuseum.org/r/ philipsaus_164.html GEC KT88 audio amplifier valve (1950s) The KT88 was introduced by GEC in 1956 for audio amplification, although the manufacturing date of the one I found is unknown. It is an example of “new old stock”, but although this valve was apparently not used, I was advised by a valve expert that about 10% of “new old” valves are gassy and unusable. The type of valve is a “kinkless tetrode”, hence the KT designation. It can utilise plate voltages as high as 800V, and in ClassAB1 configuration, can produce 100W of audio power at 2.5% total harmonic distortion, or 50W at much lower distortion. This valve is still produced today in China, Russia and Slovakia. A modern-day Russian version of this tube is reviewed in the video titled “Genalex Gold Lion KT-88 Tube Review With Audiophile Music” at https://youtu.be/q0QuC2hsWcU 12 Silicon Chip Type B3 synchronous motor. They were well known for the fine and very accurate clocks they made. Since a synchronous motor runs at the mains frequency, over the long term, such clocks are incredibly accurate because of the long-term stability of the mains frequency. Judging from the advertisement for the type B3 motor used in this device, I estimate that it is from the 1950s. Telechron motors, and the clocks they were used in, have a fascinating history. Australia’s electronics magazine siliconchip.com.au Power resistor (1950s) Here’s a power resistor from the Resistance Product Company (RPC) of Harrisburg, Pennsylvania (USA). It is a type BBM of 1.25M ±15% and has screw connections at either end. I measured it at 1.018M, which is a bit low, but consider that it is likely 60-70 years old and appears to have some burn marks. I found an advertisement for this series from 1951, stating that it is a high voltage resistor. Home or laboratory-made power board (1950-1960s?) Powerboards were not always commercially available, and in the early days, had to be custom made. Early examples were patented in the United States in 1929, 1950 and 1970. Still, the first successful commercial application seems to be an invention by Australian engineer Peter Talbot in 1972 (working at Kambrook), which was not patented. The one shown here has a master switch and five individually switched outlets. The master switch was combined with a Westinghouse brand circuit breaker of unknown rating (since the label has worn off), which was made in Sydney. Antique toggle switches (1950s to 1960s?) I found a variety of toggle switches, including one made in Australia, probably from before 1972 (and maybe long before that), when most Australian electronic manufacturing ceased. The Australian brand was Arrow Alpha, and the switch is rated at 240VAC, 10A (part number was 93A 402A). Resistance box (1950s-1960s?) The box shown below was probably laboratory-made; upon disassembly, I was surprised to see that the resistors were 5% tolerance types. But they may have been individually selected for having the desired resistances, because they are generally stable in their resistance value, no matter what it may be. It contained resistors of IRC brand (USA), ERG, Painton (UK) and others. siliconchip.com.au Decade capacitance box (1950s to 1960s?) This is a Danbridge DK4AV capacitance box, made in Denmark. It has a variable capacitance of nominally 50-1050pF plus x0.001, x0.01 and x0.1 dials marked 0 to 10, representing incremental values of 0.01µF, 0.1µF and 1µF respectively. That gives it a total possible range from 50pF (0.00005µF) to 1.11105µF. Its circuit is shown at right. In testing this item, I noticed that the values provided by the far-left dial weren’t correct, indicating that one or more of the associated capacitors might be faulty. Danbridge still exists, but didn’t respond to my inquiries. The item bears a sticker saying it was supplied by Geo. H. Sample and Son Pty Ltd. That company was established in 1921 and still exists today (www.johnsamplegroup.com). They became distributors for Hewlett Packard products in 1946, and in 1967, HP purchased the electronics division of Sample to establish their own Australian operation. Selection of Australian radio vibrators (1950s and 1960s) Vibrators were used in early valve car radios to produce the high voltages required for the valve anodes from the 6V or 12V car battery. They work by mechanically opening and closing contacts at around 100-150Hz and feeding an approximate square wave into a transformer, which steps the pulsed DC voltage up, after which it is rectified and filtered. We have published several articles on vibrators over the years (eg, in October 1995, September 2003, October 2003, December 2015). For the latest information, see siliconchip.com.au/Article/9647 and www.cool386.com/msp/msp.html Precision resistance blocks (1950s and 1960s) This unbranded set of resistance “blocks”, possibly laboratory-made, is labelled 10.000, 50.000, 100, 500, 1000, 5000, 0.1M, 0.5M and 1M, all ±0.1%. Measurements indicate that they are all out of tolerance. The resistors within these blocks are branded IRC (International Resistor Corporation), and were high-precision wirewound types of model WW4J. These were typically used in precision instruments. I found advertising for that series of resistors in US industrial electronics magazines from 1955 to 1964. Australia’s electronics magazine March 2021  13 Current source? (1950s to 1960s?) This appears to be custom made. We believe it is a low current source, and the current was set according to the meter. Examination revealed that it had two switches and a range of probably 1-100mA. They are Muirhead rotary stud switches, with a series of very low resistance shunts made from resistance wire. Patent for the Muirhead switches was first filed for in 1952 added features, or Wendell-West might have made it. But no documentation exists online to confirm that. Even though this example had melted at some point in its history, and probably hadn’t been turned on in 40 or 50 years, it functioned well. It had an outer case, but that was in very poor condition.    VARIAC (1960s) VARIAC is a trade name for a continuously variable autotransformer made by General Radio. But in Australia, Warburton Franki was licensed to use that name (it has now become generic). (UK patent GB743709A) and the USA in 1953 (US Patent US2786104A) – see the PDF at siliconchip.com.au/link/ab5u According to the US patent, the purpose of these switches was to offer low contact resistance, maintain the low resistance over a long period and provide a switch that would operate indefinitely without lubrication. Universal bridge (1960s) The Marconi Instruments TF2700 of 1962 vintage measures resistance, capacitance and inductance. This instrument is obsolete, as modern instruments provide far simpler and faster means of measuring those parameters. Transistor radio (1960s) This is a bit of a mystery. It is an “eight transistor” radio with medium wave (broadcast band) AM (MW), a shortwave (SW) band. But it has nine transistors, not eight as indicated on the front. No identifying marks as to the brand are apparent; it might have fallen or worn off, but it was made in Hong Kong. It looks remarkably similar to a Wendell-West CR-7A, which was made both in Japan and Hong Kong in 1968. However, looking at online references, we could find no information that the CR7A was ever built with SW reception. Given its remarkable similarity to the CR-7A, we suspect that it was an unauthorised copy of that model with 14 Silicon Chip The one shown here looks to be the V5 Series model rated at 600VA, with an input voltage of 240V AC and output between 0 and 280V AC, as shown in the advertisement at right (from 1963). For some interesting commentary on variable autotransformers, see https://soundau.com/articles/variac.htm Mystery Australian power supply (1960s) I found this unbranded but seemingly professionally-made (in Australia) 30V, 1A adjustable power supply in the backyard, with grass growing through it. Its main power transistor was an RCA 2N1490, introduced in 1957 and replaced by the 2N3055 in 1969. There was also a 2N657 transistor with what looked like a 1965 date stamp. It also had Australian-made capacitors in it, meaning that it was almost certainly made before 1972 when much of our industry ceased producing. It had a double-sided PCB as a subassembly. As there is no branding on the supply, it might have been made in an industry or government laboratory. Australia’s electronics magazine Precision potentiometer (1960s) This precision multi-turn wirewound potentiometer is a Beckman Helipot 7286. According to the Science History Institute (https://digital.sciencehistory.org/works/ q811kk07w), it was made between 1950 and 1969. siliconchip.com.au Helipot stands for helical potentiometer. These devices were invented in 1940 by Arnold O. Beckman for his pH meter, but were later used in radar equipment during WW2 due to their high precision. Electromechanical timing device (1960s) This item starts and stops an electromechanical timer when the start/stop button is pressed, like a stopwatch. It is reset using the rotary wheel. It runs up to 99999.9 seconds or about 27 hours. Markings on internal components suggest dates of 1964 and 1965. This item is unbranded and appears to be laboratory-made. High-power 5 resistive load (1960s?) This unbranded item looks to be professionally made, possibly in a laboratory. It contains a very large custom-manufactured, handwound power resistor on a ceramic former. The windings are coated in ceramic cement. It measured precisely 5, indicating that it is a precision component. Collection of resistors (1960s) I found many vitreous enamelled wirewound resistors. They are high-quality British-made Welwyn W24 types of 22K ±5%. These were mostly used in commercial and military equipment, but were also used in some consumer products such as early TVs. They probably date to the 1960s. This type of resistor is still produced today, with a power rating of 14W and voltage limit of 750V. TT Electronics now own Welwyn. Electronic project box made from an oil can (1960s?) Before you could visit Jaycar, Altronics or other retailers to buy an electronic project box, it was necessary to fabricate your own. The one shown here was made from some scrap galvanised steel sheet and part of an oil can. According to the Castrol website (see siliconchip. com.au/link/ab5v), Castrolite with “Liquid Tungsten” as written on the repurposed can siliconchip.com.au was introduced in the 1960s. Selenium rectifier (1960s?) Before semiconductor rectifiers such as germanium or silicon p-n junction diodes, solid-state rectifiers were made from selenium (also a semiconductor) in contact with cadmium selenide on a metal substrate, with steel or aluminium as the carrier plate for the selenium. They were sometimes known as “metal rectifiers”. Many such plates could be stacked to provide a greater voltage capability. They are not easy to test with modern ohmmeters because they have a forward voltage of around 2-5V per plate, so the ohmmeter would have to provide a high bias voltage; otherwise, they would read open-circuit. They were invented in 1933 and used until the 1960s, when replaced with silicon diode rectifiers. Grundig GDM308 microphone (1960s) According to the radiomuseum.org website, the microphone shown here was made around 1965. AWA Teleradio 60B (1960s) This Australian-made AWA Teleradio 60B transceiver used hybrid technology, with transistors throughout, except for the transmitter oscillator and final amplifier, which used valves. Its frequency range was 2-10MHz. Also, refer to the advertisement below. We don’t know exactly when the 60B model was released, but according to radiomuseum .org, the 60A was released in 1965. The only difference between the two was the value of a single resistor, reducing the output power from 35W to 25W for the 60B for regulatory reasons. One of the predecessors of the 60A/B was the AWA Teleradio 3BZ coast watcher’s radio, which was used during WW2 in Australia by coast watchers. It was an important radio for the war effort. See the video titled “3BZ coast watchers radio found in jungle” at https://youtu.be/ dT2elMKmwzM For further details and circuit diagrams for this radio, see the following links: siliconchip.com.au/link/ab5w siliconchip.com.au/link/ab5x siliconchip.com.au/link/ab5y Australia’s electronics magazine March 2021  15 Telephone bell (1960s) This telephone extension bell was manufactured in 1965 by Amalgamated Wireless (Australasia) Ltd (AWA) in Australia. It is 12/3B and is rated to ring at 70V AC. Each coil has a resistance of 500. Department of Supply capacitors (1960s or 1970s?) Here’s a package of ten capacitors from the Australian Government Department of Supply, which ceased to operate in 1974. The brand was possibly Apcos. Presumably, these capacitors were for military use. Telephone magneto and bell (1960s?) This old telephone magneto and bell might be considered a piece of kinetic folk art. The wires had become disconnected, but the idea was that the bell would ring when the magneto is turned. BWD Oscilloscope (1960s) The BWD 502 oscilloscope is from 1966. It has a 5-inch CRT (cathode ray tube) for display, as was typical at the time, and used five valves (two 6DJ8s, one 6BL8 and two 6AU6s) and 11 transistors (four 2N3694s, six BC107s and one 2N3565). I’m not sure if it works as the power cord had been cut off. BWD Electronics Pty Ltd was a Melbourne-based company which made electronic test equipment, from 1955 until the company was deregistered in 1993. It was founded by John Beesley, Peter Wingate and Bob Dewey, hence the name. The company was purchased by McVan Instruments, which is now the Dutch company Observator Instruments (siliconchip.com. au/link/ab5z). Many documents such as manuals and advertising related to BWD can be found at www.kevinchant.com Voltage reference (1960s or 1970s?) This voltage reference is home-built or, more likely, laboratory-built. It uses a 1N429 zener diode as a voltage reference. 16 Silicon Chip Hi-Need electronic sample book (1960s?) This electronic component sample book contains samples and technical information of every component the Japanese company sells or sold. We could find no reference to this company online. The components appear to be of mid1960s vintage (many different types of components are stamped with either “64” or “66”). See the video I made titled “Hi-Need electronic component sample book” at https://youtu.be/ C0tqY89MiTk Dual power supply (1970s) Modern power supplies have become quite small, especially compared to this one, given the modest output it produces. It provides a relatively modest 2 x 0-20V at 1A, yet occupies a 19-inch rack enclosure. The semiconductor date stamps show 1978. Timer/counter/frequency meter (1970s) This piece is presented as it was found. Examination revealed a semiconductor with a date stamp of 1974, so this would be its approximate manufacturing date. The device was unbranded, but it had a circuit board inside labelled “RMIT Department of Applied Physics”. It could have been a teaching aid. CB radio power supplies (1970s and 1980s) Many readers will remember these; Australian-made 12V, 2A power supplies for CB radios used in base-station configurations, created for the 27MHz CB craze of the late 1970s and 1980s. Later, UHF CB on 477MHz took over. Unlike modern power supplies, these were not switchmode but used a transformer and rectifier. I found many of these in the hoard, mostly with their cords cut and evidence of having been exposed to the elements. The example shown is the Panther brand, which was either made or distributed by G.A.F. Control Pty Ltd in Melbourne. It had approval number V77486/ PS132. Australia’s electronics magazine siliconchip.com.au e u g o l a t a C 2021-22 ! W O N T U O 00 new lines! 2 1 r e v O . s ic n st in electro te la e th h it w d 424 pages fille Yours FREE with this issue of Silicon Chip. If you didn’t receive your copy, contact your newsagent or register at www.altronics.com.au/catalogue to receive one by post for FREE! 1300 797 007 ® Shop online 24/7 <at> altronics.com.au Build It Yourself Electronics Australia’s electronics magazine MarchCentres 2021  17 siliconchip.com.au Akigawa L-120B multimeter (1970s or 1980s) This photo shows a late 1970s or 1980s miniature analog moving-coil multimeter, with a mirrored scale and 2mm jack sockets. It has a typical-for-the-era 20k per volt DC meter impedance. It is a neat piece, but I couldn’t find any reference to it online. Analog meters aren’t obsolete, and still have niche uses today, such as watching values change that would be too fast to see on a digital meter. However, due to their lower impedance than digital meters, they do load circuits more. Electronics Australia Low Distortion Audio Oscillator (1980s) This was built from a kit, described in the December 1986 and January 1987 issues of Electronics Australia. It featured an ultra-low-distortion audio oscillator in the range 10Hz to 100kHz with a very stable output level. The low-distortion feature is vital for the accurate setting of steep-cut notch filters and measuring the low distortion of modern amplifiers. It was built with the optional meter which would have cost an extra $25. Apart from some dirty switch and potentiometer contacts, it still works well. The table below shows a comparison of the distortion specifications of this oscillator with those of a commercial HP 209A (first made in 1968, but still in use today). Clearly, the EA project was an outstanding performer! Frequency 20Hz 100Hz 1kHz 10kHz 20kHz 100kHz EA design < 0.0075% < 0.0015% < 0.001% < 0.002% < 0.005% < 0.02% HP 209A in low-distortion mode 0.085% 0.077% 0.038% 0.047% 0.055% 0.051% Table 1 – sinewave THD performance comparing the EA signal generator with the HP209A Realistic SA-10 (1980s) This low-cost Realistic SA-10 audio amplifier was a surprisingly popular amplifier, produced from 1975 to 1994. It was sold in Australia by Tandy (owned by Radio Shack in the USA). They started production with a silver face, which was changed to black in 1979. Even today, they are popular as a bench test amplifier (despite mediocre performance at best!). This one has a QC mark date code of 1985. There were three versions produced, including a discrete version and an IC-based version. All had an output of 1W/channel with 10% THD. See the video titled “Realistic SA-10 stereo amplifier” at https:// youtu.be/K8DvfmOkDDc This one is the 31-1982B, with a ceramic cartridge input (popular at the time) rather than a more modern magnetic one. 18 Silicon Chip Homemade breadboard rig (1980s) This looks like a home- or laboratory-made breadboard rig which includes a signal generator, frequency meter and multimeter. It is made to a very high standard. Inside are Intersil 7107 LED DPM and Intersil ICM 7226A evaluation kits, as well as some custom boards. The Intersil boards provide the 3.5-digit LED display, A/D converter, voltage reference and clock; and 8-digit multifunction frequency counter and timer respectively. For further information on the ICL71XX series see siliconchip. com.au/link/ab60 and for information on the 7226A, see siliconchip. com.au/link/ab61 We estimate this piece is from the early 1980s, as the 7226A IC had a 1981 date code on it and the unit employed Australian-made Ferguson transformers. Speedie Walkvision TV (1990s) A near-totally useless item (today!) is this battery- or DC-operated monochrome TV. According to radiomuseum.org, it would have been made around 1990. “Test Master” (1990s) This looks like it might have been made from a kit but we could not identify it as being from SILICON CHIP, EA or any other Australian electronics magazine. It is a beautifullymade test apparatus that provides power, audio amplification, square and sinewave generation and transistor test functions. Unusually for a homemade device, it includes cable-lacing and edge connectors. We found a receipt inside for a component used to build it from Dick Smith Electronics, dated 1991. Electric fence energiser (1990s) Here’s a weatherbeaten, Thunderbird M200 electric fence energiser, probably from the 1990s or 2000s. These units were made in Mudgee, NSW by Country Electronics Pty Ltd. As with many devices in the hoard, the power cord had been cut off, so its working condition is unknown. We couldn’t easily open the unit to inspect it because, even though it had a screwon back, it had also been sealed with adhesive. It is mains-powered and can energise up to 20km of electric fence with 6.8-7.2kV “zaps” to encourage livestock not to try to cross it. It consumes about 7-11W. Australia’s electronics magazine siliconchip.com.au Electret microphone (1990s) The Realistic/Radio Shack 33-1065 stereo electret microphone shown here was discontinued around 1992. The individual microphones are hinged for storage or greater spatial separation. It is battery-powered and was made in Japan. As a matter of trivia, this model was used as the basis of a movie prop in Ghostbusters 2 (the “Giga Meter” – see below). Helping to put you in Control Universal Input to 4-20mA Transmitter Universal Thermocouple, RTD and voltage Input to 4-20mA Transmitter mounted in an IP65 weatherproof box. SKU: KTA-367 Price: $132.28 ea ESP32 Controller Arduino-compatible ESP32 controller with 2 relay outputs, 2 transistor outputs, 2 optoisolated inputs, 2 0/4-20 mA analog I/Os, 2 0-10 VDC analog I/Os and 4 GPIOs. Interfaces using USB, RS-485 serial, I2C, Wi-Fi or Bluetooth. DIN rail mountable. SKU: KTA-332 Price: $251.90 ea Sinclair multimeter (1970s) Sinclair made a variety of innovative products such as calculators (from 1973), electronic watches (1975), handheld TVs (1983) and the ZX80 (1980) and ZX81 (1981) computers. This PDM35 multimeter was released in 1979. Sinclair was a company known not to waste anything, hence their low prices. Inspection of the multimeter reveals that the case has been repurposed from Sinclair’s line of calculators. Descendants of the Sinclair companies still exist. After the company broke up around 1978, there was a series of spin-off companies and mergers and acquisitions. Since 2013, what remained of Sinclair is now known as Aim-TTI or Aim and Thurlby Thandar Instruments (www.aimtti.com). Digirail OEE WiFi The DigiRail OEE is the ideal tool to monitor and examine the performance of your production lines. It reads the sensors that monitor the operation of machines, devices or processes and determine operation time. SKU: SIG-111 Price: $241.95 ea N1030-RR PID Temperature Controller N1030-RR Compact sized PID Temperature Controller with auto tuning PID 230VAC powered. Input accepts thermocouples J, K, T, E and Pt100 sensors. Two Relay outputs. SKU: NOC-322 Price: $105.55 ea 750W ELDM Brushless AC Servo Motor Leadshine ELDM8075V48HM-A4 750 W brushless AC servo motor with 1000 line encoder. SKU: MOT-457 Price: $306.85 ea Other reports on electronic hoards David Jones from EEVBlog investigated another Australian hoard. However, that one was extremely neat and well-organised, with a staggering number of salvaged electronic components as well as a collection of SILICON CHIP magazines. See the video titled “EEVblog #737 - World’s Biggest Collection Of Electronics Components” at https://youtu.be/x8nbHYOc8ns Helping people like me in future When you make an electronic device, it would be a good idea to place a label inside describing what it is, the source, when it was built and who built it. That will make the job of future electronics archeologists much easier! SC Brushless Servo Motor Drive The ELD2-RS7030 brushless servo drive, power range from 25W to 1200W, are special DC input, motion control product designed for machines and applications that request a best balance between reasonable cost and outstanding performance with MFC/vibration suppression. SKU: SMC-411 Price: $380.83 ea RTD Temperature probe with magnet fixing RTD probe with magnet fixing for surface temperature measurement. -50 to 200 ºC. Silicon Cable 3 meters. SKU: CMS-007 Price: $142.95 ea Help for hoarders If you Google “help for hoarders”, you will find a large number of resources to help such people. The Victorian Government, for example, has a web page on the problem at https://www2.health.vic.gov.au/ageing-andaged-care/wellbeing-and-participation/hoarding-and-squalor I’m sure other states would have similar. siliconchip.com.au For Wholesale prices Contact Ocean Controls Ph: (03) 9708 2390 oceancontrols.com.au Prices are subjected to change without notice. Australia’s electronics magazine March 2021  19