HV Transistor ENi-1 V1
Some waveforms and Voltages seen and measured on a working CDV-700 / LENi mod, in preparation to try a Russian PNP Ge. transistor in that circuit.
First tests are made with the original, hand selected by ENi HV transistor marked ENi-1. The only difference I have found between ENi-1/ENi-2/ENi-3 transistor is the gain factor. They all appear to be a 2N404 as available in 1962, all are PNP, and are all the same physically, but segregated in their own gain into rough groups, with frequent overlap in those groups as tested today. Gain variants were quite common in the early 60's when the manufacturers would make huge runs of a "type", then measure each one to see what they had actually turned out to be. There were hundreds of part numbers back then, populated by individually selected transistors from a single production run. We still deal with that same issue today in certain semiconductors, but instead of different numbers, they are rated to different tolerances. Needless to say, devices with the exact same part number and no tolerance specified, as available to hobbyists today (eBay etc.) are all over the place in terms of performance, but usually nowhere near the stated value. To me this indicates what's being sold are off-falls from the grading process, even if they are in tape-and-reels.
I tried to document the base and collector DCV, ACV P-P (peak-to-peak), the frequency in Hz at each, and a waveform at each, to compare to any differences when simply substituting V1 with a Russian transistor. The emitter in grounded in the LENi V-1.
The Russian transistors are the same germanium type, polarity and pinout, but a few differences in construction are obvious (the base lead is also the metal case). In separate and not shown here gain measurements, the Russian transistors have a more consistent gain factor, and in al cases, it was as high or higher than the best category in the ENi-1/ENi-2/ENi-3 hand selected lots.
Pictures and data will be in the next posts.
Note: in the Scope/Analyzer I use, the waveform is scaled automatically by the smart probe, and the Voltages are measured by a 3rd. wire in the scope probe so don't need to be scaled (what they read is direct). It is rated to 2000V so beware, on some measurements, they may cause damage your scope if duplicated.
Geo
