Re: [EE]: a curiosity - RCA -> Miniature Light Globe pendant?

I've had success identifying objects by describing them to grok. So I 
tried submitting your post to grok and this was the reply.

>>>
It's likely a vintage leak detection light (often called a "leak 
light" or 
"bore light") used for repairing woodwind instruments like clarinets, 
flutes, oboes, or piccolos. These tools are inserted into the instrument's 
bore to illuminate the interior, making it easier to spot air leaks 
through pads, joints, or cracks by observing where light escapes. The 
small size fits narrow bores, the slot directs the light beam (preventing 
it from shining everywhere), and the RCA connector plugs into a 
low-voltage power supply or control unit (common in older repair kits to 
avoid high voltage near delicate instruments). The incandescent bulb runs 
on low voltage (around 1.5V or so) to keep heat minimal and safe for wood 
or metal surfaces. Modern versions use LEDs, but vintage ones like the 
Erick Brand "clarinet lamp" (or similar) relied on incandescent globes. 
The reverse image search results make sense—its probe-like shape resembles 
dental tools or injectors, but the context fits musical instrument repair 
best. If you have access to a low-voltage power adapter (start at 1.5V to 
test safely), you could try replacing the bulb with a compatible 
grain-of-wheat type (e.g., 1.5V, 30-50mA) from electronics suppliers.
<<<

In the past I've found you can tell grok that this is not correct and to 
try again. You can tell it why you think its answer is wrong and it 
will refine its search. After a few trys it seems to find what you are 
looking for.

Friendly Regards
Sergio

On Mon, 26 Jan 2026, Justin Richards wrote:

> I have had in my collection a small 10.5mm (0.4") D x 51.5mm (2") L
> cylindical device with an RCA connector at one end and at the other a small
> slot behind lies a small incadesant globe. Image is hopefully attached.
>
> Sadly, the globe is blown and has no specs on it or the cyclinder it is
> housed in.
>
> Wiki suggests the lowest voltage incadestant globe is about 1.5v.  As such,
> I guess it is not used to indicate normal RCA socket signal levels
>
> I submitted image for a gargoyle search but it suggested a dentist tool or
> diesel injector.
>
> Any guesses?
>
> Cheers justin
> [image: rca_light.jpg]
>
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