Name that Ware November 2018

The Ware for November 2018 is shown below.

Thanks to phantom deadline for sharing this ware! I enjoyed reading up about it.

13 Responses to “Name that Ware November 2018”

  1. Jeff Epler says:

    So far I found that the PMI part is probably an op-amp OP37 with 1826-1349 being a HP part# and leaving 9449 as a date code. PMI (Precision Monolothics) was acquired by Analog Devices in ’90 according to wikipdia.

  2. banjaxed says:

    “Coil” suggests it’s a driver circuit for an automotive fuel injector?
    The DIP socket probably holds the low-impedance driver IC, which would be prone to damaged and may need replacing.

  3. SAM says:

    It looks a lot like there are some pieces missing:
    A 14-pin DIL in the socket (obviously) and a TO-66 (the slightly smaller sibling of the TO-3) in the middle with the case mounted to the holes with the rivets and the two pins sticking through the non-plated hole and possibly connected to the slightly tarnished pads.
    And something has been desoldered from the three pads on the left.

  4. atsampson says:

    The form factor reminds me of a meter driver board – something like the VU meter driver on the right here from CML:

  5. carl says:

    The two large plated holes in the center suggest an analog meter mounting to me. A dashboard gauge ? Perhaps a tach ?

  6. Dennis Boone says:

    This seems to resemble a current loop transmitter circuit, e.g. for use in a PLC sensor environment, or perhaps the old teletype serial communication loops.

  7. Brian says:

    I’d guess this is PCB board off a YTO (YIG tuned oscillator), unsure of the exact HP model number. If so, this board would usually provide bias filtering, and this one looks to have part of the driver circuit as well.

    HP sometimes used ribbon cable interconnect terminated in a DIP header for the YIG control interface, search e*ay for HP 5086-7268 to see a typical YIG driver (not this one) with a ribbon cable control attached.

  8. Brian says:

    Here’s another picture of a typical YTO driver, this one with a 0.1″ header for control, and a similar op-amp & transistor setup:

  9. Brian says:

    Following up on my earlier guess, after looking quickly though various YIG pictures, this board appears to be very similar to (perhaps a later version of) the PCB on a HP 5086-7272 YIG multiplier from an 86290B sweeper

  10. Jack W says:

    Short answer: driver board for a YIG oscillator (see

    Found this eBay listing for a similar board based on searching for the labels on the board and various test equipment manufacturers:

    This article ( on the HP 8566B confirms that it is a “A20 YTO [YIG-tuned oscillator] driver” board. Looking at pictures of YIG oscillators on Google shows a lot of similar looking boards.

  11. Jeff Epler says:

    huh so the DIP socket is actually used as a board-to-board connector. Not sure if it works to link to a photo, but here’s an e.g.,: