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

On 2026-01-26 4:53 a.m., smplx wrote:

Hi, Sergio: -

Good find, that looks like a possibility. Here's a fairly unsafe looking 
"vintage" light of this kind on eBay "Leek Light".

https://i.ebayimg.com/images/g/D9MAAOSw1kBnsQa3/s-l1600.webp

https://ebay.us/m/sSIp8A


It uses a standard (for the 1940s) #44 6.3VAC panel light. And has a 
120VAC two-pin plug. And has exposed metal on the #44 bulb.


We can safely assume there is not a high-tech isolated GaN SMPS hidden 
in the plug.

So I'm guessing a series resistor in the form of the power cord. The 
bulb is 250mA so the cord would have to dissipate close to 30W. It will 
get toasty- better not coil it up in a bunch.

P.S. Searching for this kind of niche product is a real pain, Google 
ignores quotes when it feels like it these days  and it would prefer to 
find "light leak" which is a photography technique to simulate a 
defective film camera, from what I can see. Also making lights (lamps) 
in the form of leeks (and cellos) is not uncommon. It's a subtle form of 
enshitification- they are assuming (probably correctly) that an error 
from the user is far more common than someone looking for a rare vintage 
gadget and are serving that need preferentially.

Best regards,

Spehro Pefhany




> 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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