I have seen a documentary about making BGM-71 TOW (an anti-tank missile - the Iranians make it). You can see it in this link (part 1). I have seen two odd components. In your opinion, what are these components?

The first component is this (at 4:17 minute):

enter image description here

The second component is this (at 4:38 minute):

enter image description here

Here's another picture of the second component (at 4:50 minute):

enter image description here

  • 2
    \$\begingroup\$ The second component kind of looks like a large wattage resistor. The first, I don't have a clue. \$\endgroup\$
    – horta
    Commented Jun 24, 2014 at 12:44
  • \$\begingroup\$ I think it is just a stamp. I watched the video at that point and if you see how it is applied, it doesn't look like a component. \$\endgroup\$
    – HL-SDK
    Commented Jun 24, 2014 at 13:11
  • \$\begingroup\$ this^ that looks like a stamp to me too \$\endgroup\$ Commented Jun 24, 2014 at 13:18

1 Answer 1


Difficult to see from the photos but the second component doesn't look like a resistor to me, but a plated metal enclosure rather like those used to package crystals, only larger.

What's inside it? Not a clue, but my guess would be a SAW filter or crystal filter, physically large enough to need such a case.

These sometimes come in odd packages.

  • \$\begingroup\$ I was thinking the same thing, but I could not find any crystals large enough to fit the bill. It could be, as you said, just a metal enclosure for something else. \$\endgroup\$
    – sherrellbc
    Commented Jun 24, 2014 at 13:42
  • \$\begingroup\$ There certainly WERE larger crystals in use in the west (WW11 era) but my suspicion is something composite (filter : possibly RF mixer?) rather than a single element. \$\endgroup\$
    – user16324
    Commented Jun 24, 2014 at 13:45
  • \$\begingroup\$ Yes, I have seen the same package for 32.768khz crystal but this is so much big. \$\endgroup\$
    – Roh
    Commented Jun 24, 2014 at 14:04

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