![]() ![]() In 1962 Tri-ang introduced the kit "A/B", This added five more printed circuits and other components including another RF transistor in the TO7 package, probably a Mullard AF11n type. Even later kits contain Mullard OC series transistors. TR1" and "TR2" but in metal cans with plastic sleeves that are probably later Ediswan types. John has other Tri-onic kits and some have transistors marked "A.E.I. TR5 is the TR2A and is described as being the AF transistor, which John thinks may be an Ediswan XB102, XB103 or possibly XB104. This transmitter is working in VHF band somewhat between 50 210MHz. (Experiment with the length to get optimum performance). (Can be found on old transistor radio boards). TR4 is the TR1A and is described as being the RF transistor, which John believes to be an Ediswan XA101 or XA102. T1 can be a radio frequency transformer with built in capacitor. These kits contained components in plastic housings with connecting pins that plugged into a series of circuit boards, Tri-ang designated the "A" set transistors as TR4 and TR5. ![]() John's 1961 "A" set contains two top hat transistors marked "A.E.I. These sets were probably only produced from 1961 until 1963. I am grateful to John Hills of Oregon in the USA who has explained that these TR1A and TR2A transistors were supplied to Tri-ang (Lines Bros) for use in their Tri-onic kit sets. Ediswan fell under the AEI umbrella, but why did AEI brand these two transistor types as their own? the night sounds of AM radio on my pink and silver Pacific transistor-6 radio (made. What is really odd about them, apart from the fact that I cannot find them in any data book (and I have a *lot* of data books on germanium transistors) is that they use the black-painted 'top hat' encapsulation that is unique to early Ediswan transistors. 1420 Wbsm Wbsm Radio Station Primary Industries Broadcasting Media. Transistor radios contain hundreds of solder joints where the component wires meet the circuit board traces. Old batteries were prone to leaking corrosive goo that forms an insulating insulator on the metal parts, preventing contact between the battery and terminals. ![]() I have a multimeter and signal generator but no oscilloscope."Here are two unusual transistor types, marked AEI TR1A and TR2A. Battery holders are probably the main enemy of old portable radios. Now the only frequency measurement I get is 1.6 MHz at the collector of the first transistor. Something went wrong after I tried to fix the intermittent longwave reception. It was working almost perfectly after replacing old electrolytics and the Ge transistors with new ones and I was even able to measure the IF of 465 kHz at the collector of the last RF transistor. However, I am confident that the audio section is working fine as I was able to connect my MP3 player and play it at full volume without distortion. It only passes a faint test signal from the base of the second RF transistor to the audio stage, but a strong one from one terminal of the second IF transformer. Suddenly it is unable to receive any stations, neither will it pass a 455 kHz test signal from the external antenna input to the audio stage. The radio has four RF transistors, four AF transistors and a Germanium detector diode. I am repairing an old four band Transistor MW+ SW radio for which a circuit diagram is unavailable. ![]()
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