1. Those remind me of the radar remote control panel switches from a AN/GPN-12 airport surveillance radar and AN/TPX-42 Interrogator set. What a flashback from my ancient Air Force past.(early 1980s) If you held them depressed for a little while, it would short out the driver transistors for the light bulbs. We kept large quantities of 327s on hand due too the failure rate. Probably from the effect of the snap switching on the bulb filaments.

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2. We used these, or something similar for indicators/switches in Nuclear plants on the Military ships. I recall changing lamps on a regular basis, even with the thousands of hours.

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3. it's just clickage.

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4. sweeeeeeeet!

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5. I thought I recognised those switches, the Korry light assembly company was involved in the minuteman nuclear missile program.

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6. Proper well made switches with a proper clunck😃👍

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7. Those little sods run hot but I have to disagree with the guy that reckoned the bulbs were reliable. Maybe the company just used trash bulbs but we'd be replacing those every month or so. There's two so you have redundancy but it wasn't uncommon to find a system with at least one if not both out.

   I'm often amazed at the heat tolerance of a lot of aviation equipment. It isn't uncommon to find Nav units and PFD's that are screaming hot, all the time. I sometimes wonder how the components survive, especially with the thermal cycling! Newer things like the G1000's run a lot cooler thanks to active cooling and more efficient design but man some of the older stuff is nuts.

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8. Ah, "proper" switches. I've used these before, very good switches.

   If these are the mil-spec version, they're quite expensive (approx £1000 each, if I recall correctly). They're expensive because they function as a switch (i.e. not as an intermittent contact, not as a hair trigger, not as a fixed short or open) under nasty shock and vibration environments. The push weight is carefully thought of – they're not likely to get activated by idle fingers, or hands that have got thrown around a cockpit in sudden buffeting, etc. The size is also important – compatible with gloves, or anti-flash clothing. The price is high partly because they're tested against these specifications.

   So, whilst £1000 sounds expensive, it's a lot cheaper than failing environmental testing, or some vital configuration being changed inadvertently when there's an explosion or buffeting, leading to a ship not being able to fire back or a plane going down.

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9. If a thing's worth engineering, it's worth OVER-engineering. Nice clicketage/clickage/clicketyage! Getting the right color rendition for those back-illuminated reds without affecting skin tones is tough unless you do some very fancy color-grading, but your description works perfectly. Another entertaining and informative video.

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10. The NSN of the bulb holder was assigned in March 1976, Bytor noticed the contract date of 1985 and the listing I found showed the last procurement date of 2014! I wonder if they were still being manufactured or were they pulled from (very)cold storage!

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11. Wow. those bring back some memories. When I was in USAF in the early 70's we had tons of these on our equipment and in the CP. I was in maintenance and I remember the bulbs, 327's i believe went out quite a bit. We got to the bulbs with a special tool wrapped around the lens and popped it off. Fun times.

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12. Excellent content.

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