A.C. Gilbert Erec-tronic* Sets
Last updated 1/28/05
Most people who are familiar with mid 20'th century electronics and the name "Erectronic"* associate that name with A.C. Gilbert Company's "electronic Erector sets", sold around 1960. These sets allow someone, even a child, to assemble a working radio set in a few minutes without using tools, or soldering.
What the Erectronic set consists of and how it is used can be summed up by the following "instructions" almost quoted from the box lid of one of the sets:
1. Place template (printed page) on mounting board (pegboard, also called a breadboard) with holes in template lined up with holes in board.
2. Place electronic parts, already mounted on numbered plastic bases, in places shown on template.
3. Use clip-on wires to make solderless connections with terminal posts on each component's base.
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Why This Web Page?
This writer feels that his most unique Christmas gift was an Erec-tronic set, received in 1958. The set was battery powered and had a vacuum tube and a crystal diode. Several different radio receivers could be built using the set. Unfortunately none of the parts except for one resistor survived rough treatment. (That remaining resistor has since been soldered into another Erec tronic set acquired recently via eBay.)
The unique feature of the Erectronic set was its Jiffy Connector (tm) which was the wire with clips at the ends. The clip itself was patented by an A.R. Jubenville in 1951, the patent number is 2,578,360. The U-shaped clip is typically of solid steel or bronze wire, and for the Erectronic set parts, clips onto a metal terminal post about 1/8" in diameter.
A.C. Gilbert introduced its line of Erec tronic sets around 1958. But for a few years prior, a small company in Cambridge, Mass. named Science Electronics, Inc. manufactured, marketed, and sold them, under the names "Erectronic Set" and "Erectronic System". Undoubtedly the name "erectronic" alluded to "Erector", a famous Gilbert trademark for the latter's metal girder toy construction sets.
We are not sure of the relationship between A.C. Gilbert and Science Electronics. Some later sets are labeled "Science Electronics, Inc. division of General Electronics Laboratories".
According to the dates on their instruction manuals, the first toy Erec-tronic set that Science Electronics produced was their model T-200 (one vacuum tube, 1955) followed by the T-150 (one transistor, 1956) and then the T-175 (two transistors, 1958). The tube set used one flashlight battery (cell) and a 45 volt radio "B" battery. Portable radios of the era were similarly powered, with a 1-1/2 volt "A" battery to heat the tube filaments and a 45 to 90 volt "B" battery as the primary power supply. The Erectronic transistor sets used just a single flashlight battery that was supposed to be able to power the radio for ten days playing continuously.
Click here for picture of Science Electronics' model T-200 set
The templates for the T-200 set do not have the name "Erec tronic" on them. It is possible that the T-200 set may have been packaged and sold under a different trademark, although we have no samples or evidence. The templates were copyrighted in 1954. These templates also have much of the content of the T-200 instruction manual (in different words) printed directly on them, as if any set or kit marketed prior to the T-200 did not have a separate instruction manual.
Literature for the toy sets proclaimed "This is not a dead-end set. ... with Add-to-it kits more circuits can be built ...". This writer has seen one (model #201) of three advertised Add-to-it kits for the T-200 set:
#201 -- Booster stage with one vacuum tube
#202 -- Booster stage with vacuum tube and loudspeaker
#203 -- Geiger counter kit
This writer has not seen any descriptions of Add-to-it kits for the transistor Erec-tronic sets although the above Add-to-it kits together with a 45 volt battery could be used with those sets also.
Science Electronics' primary product line was industrial grade sets for use in trade schools and colleges. Most were packed in wood cases about the size of attache cases or suitcases depending on sophistication. Usually the perforated breadboard was in the lid. These sets also bore the Erectronic name. Some were quite large, with hundreds of components, for example the model BE-8 which came in a 26" x 22" x 12" wood case with plastic parts drawers and which weighed nearly 90 pounds. As far as we know, the bases on which the components were mounted have always been of yellow plastic. The toy Erec-tronic sets came in cardboard boxes.
Click here for picture of Science Electronics' model BE-5 set
Many of the industrial grade sets and also the T-175 toy set had white outlines on the perforated breadboard(s) so that the components would be pressed onto the breadboards after use. A stockroom clerk could quickly verify that the set as checked in after use by a student was complete.
Industrial grade sets used 120 volt power. Terminal posts with full line voltage are exposed, and it was possible with less than careful handling for a component base to work loose from the mounting board and a short circuit to result.
The first Gilbert Erectronic set appears to be its model 11175. This set is identical to the Science Electronics T-175 set except for the instruction manual cover and the box lid, and had minimal changes to the text and graphic content of the circuit templates and manual. This set was labeled with the subtitle "American Science Series" which label later sets did not carry. In our specimen of this set, the plastic bases of a few of the parts are stamped "Science Electronics, Inc.". To the uninitiated, that name could have been taken to be the name of a parts supplier as opposed to the former manufacturer of the sets.
At about the time Gilbert began selling the toy Erec-tronic sets, some improvements to the circuits were made. A crystal electrostatic plug type earphone, probably less expensive as well, was substituted for the electromagnetic voice coil type headset.
About 1961 Gilbert changed the internal packaging of the Erec-tronic sets. Plastic foam inserts were substituted for the cardboard inserts that held the parts. The Jiffy Connectors were modified with stamped metal clips instead of the bent solid steel wire clips at the ends. The wire leads of the electronic components were connected directly to the terminal posts on the plastic bases rather than being crimped to a spade lug in turn attached to the post. The plastic bases were redesigned and were stamped with the Gilbert trademarked style of the word "erectronic" with the R, E, C, and T underscored.
Click here for picture of a Gilbert Erec-tronic set (model 11063)
One unfortunate change Gilbert made was to renumber the pin connections to the vacuum tube. This departed from the industry standard for the pin connections and also made the 1960 and later Erectronic sets inconsistent even with Gilbert's own sets of the previous years.
Additional miniaturization of parts had taken place by the time the latest Gilbert sets were introduced. This includes the loudspeaker (upper left) and variable capacitor (left center). Smaller fixed capacitors from that shown bottom center would not become common until transistor circuits using voltages in the single numbers became common.
(Photo credit, J. Manush)
As improvements were made, Gilbert changed the model, or catalog, numbers. According to a parts list, Gilbert offered in one year (content deduced from listings in ebay.com):
11042 -- Crystal radio kit, 3 circuits
11052 -- Small one transistor set, 4 circuits
11062 -- Large one transistor set, 10 circuits, similar to Science Electronics T-150 set
11072 -- Vacuum tube set, 15 circuits, similar to Science Electronics T-200 set
11082 -- Has two tubes, relay, photocell, loudspeaker, but no transistors. 19 circuits.
Add-to-it kits were not mentioned in the Gilbert parts list. The model 11082 set is more or less the equivalent of Science Electronics' model T-200 set plus Add-to-it kit #202, with parts for still other circuits added.
We believe that Gilbert discontinued Erectronic sets in 1961 or 1962. Founder A.C. Gilbert himself passed away in 1961. The company was headed downhill financially and was acquired (by Wrather Corp. and later by Gabriel) a few years later.
Sets in our collection:
Science Electronics, Inc. sets:
Model T-150 One transistor set, 9 circuits.
T-175 Two transistor set
T-200 Vacuum tube set, 15 circuits.
BE-5 Industrial grade set -- This set did not come with templates or an instruction book and the parts are not numbered.
2-RF Industrial grade set -- This set has its own templates, and numbered parts compatible with the toy (T series) sets.
A.C. Gilbert Co. sets:
11175 Two transistor set
11053 Small one transistor set
11063 Large one transistor set
The 45 volt "B" battery is hard to obtain. Five or six common 8-1/2 to 9 volt rectangular batteries together with some alligator clips can be used in its place.
Because of the numerous crimped and other mechanically fastened connections, oxidation over the decades has made the electrical performance unreliable. We have soldered thin jumper wires between the component leads and the terminal posts of a small number of component assemblies in some of our sets. We have not tested all of the components in all of our sets. Some components, notably electrolytic capacitors, have undoubtedly deteriorated over time. The components themselves were industry-standard, including those from then well known manufacturers Meissner (coils) and Cornell-Dubilier (capacitors).
Other companies continued to produce electronic hobbyist kits. Many of these newer sets used springs, which gripped both the leads of electronic components and the ends of plain wires, to make solderless connections. One company (we forget its name) had electronic components completely encased in small plastic boxes with magnetic pads on the outsides to make connections. A competing line of sets, trademarked Lab Volt, were also used by schools and colleges. They also have components mounted on (red) plastic bases, with corrugated metal fins instead of studs for terminals. Clip on wires of a different design are used to make connections.
* The name has been spelled "Erec-tronic" or "Erectronic". We have used both spellings to induce Internet search engines to show the link to this page more prominently.
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