KBK update for Thursday, 16th January
With the help of Holm Tiffe and the Robotrontechnik-Forum, we have made some progress understanding the Hall IC scene of the past. It seemed unlikely that VEB HFO B 461 G was around at the introduction of RAFI RS 74 C, and this was compounded by RAFI RC 72 C offering a variety of outputs (including separate level and pulse types) beyond what HFO are known to have produced.
According to the Ältester B461G? (oldest B 461 G) topic at the Robotrontechnik-Forum, B 461 G is known to go back to 1981, which corresponds with the age of TGL 38658, from June 1982. This indicates that RAFI must have been using an older product range, and this is reported to be Siemens Hall ICs. Unsurprisingly, the Siemens data matches up exactly with the RC 72 C data.