On 2020-Jan-17, at 4:04 AM, Guy Dunphy wrote: > At 02:22 AM 17/01/2020 -0800, you wrote: >> >> On 2020-Jan-17, at 12:11 AM, William Maddox on CCTalk via cctalk wrote: >> >>> The seller thinks this may be a drum memory, but it is clearly not. My >>> guess is that it is some kind of clock generator. Anyone recognize this? >>> >>> https://www.ebay.com/itm/Vintage-Mainframe-Computer-Part-Drum-Memory-Control-Data/312942951497 >> >> >> The circumferential wire bundles feed two-stage transistor amplifiers that >> drive toward the center, then drop down to the interior board through >> inductors and then feed back toward the circumference near the coax >> connectors. > > Reversed. The wire bundles are LF power. The radial circuit drives from the > center outwards towards the TNC connectors. > Judging by the progression of semiconductor beefyness.
Nope. Trace the circuit. Going inwards, wire from bundle -> feedthru cap -> 2N2222.B 2N2222.C -> 2N2905.B 2N2905.E -> Rs, drops down thru choke, connection from there inward to diodes and outwards to the coax. Power is coming from a couple of out-of-regular-displacement connections in the wire bundles. > The thing at the center looks like it might be an avalanche diode pulse > generator. The diodes appear to be 1N5719 which are HF switching PIN diodes. > Maybe. Something to generate a very fast edge. > Someone wanted those coax signals to all be very precise and coincident. Now > where... Oh yes, 'physics packages.' > My guess - nothing to do with computers, but rather an implosion detonator > for a nuke. Yes, that's a little dramatic, it doesn't look engineered highly enough for that. > Or something less drastic, like explosive metal forming? > That board with 'DISCH' and 'GATE' might be > some kind of coincident/code detector, related to making sure > the round thing doesn't fire except when it's really supposed to? If they are > related at all. The board with DISCH on it is from 1966 or 68, the round thing from 1982(+). Improbable they have anything to do with each other. >> It looks like one of the coax connectors (J26) is out of regular angular >> displacement from the others. >> I'm wondering if it could be some sort of rotating / multi-phase modulator. >> An RF carrier injected on the odd-one-out coax connector, modulated or >> switched in a rotating sequence via the circle of drivers, out to the circle >> of coax connectors. >> Sheer guess as I've never seen one, but perhaps for a VOR station, to set up >> the (electronically-generated) rotating beacon, the coax connectors would >> feed out to RF amps and a circle of antenna segments. > > Nah, that's fast circuity but not AC RF. The RF wouldn't be going through the transistor circuitry, they're just switching/modulating. The connections to the coax connectors aren't discernible but what makes sense and coincides with the driver circuit, is RF injected on the odd-one-out coax, connected to the centre ring (diode cathodes), switched through the PIN diodes by the transistor drivers, then out to the ring of coaxes. Looking at some pics, there are a lot of VOR designs out there, a lot of them have 48 lobes. But a couple of hazy pics look to count to 50 lobes, which is 2* the number of elements around the ring. Just a guess, but it's making some sense. >> It looks a little too engineered to be for a lab experiment. > > Very definitely. Lots of work in that round thing.
