Has anyone tried one of these $20 (or so) USB borescopes? They any good? Do they light up?

E.g., it would be useful to have one for inspecting for potential sludge build up in a car that you are planning to purchase--just open the oil cap and push it in and see

 

What can you lose for $20 but my borescope was about $300.

 

I don't know which one you are referring to but I bought this one about 2 years ago paying about $40 at the Amazon.


I found it not OK to use for my purpose which was to see the cylinder because the diameter was a bit bigger than the spark plug hole. So I decided to remove the aluminum cover which is surrounding the C-MOS camera unit. After that, I could use it to see the cylinder.

But there was a noise problem and I could not see things well enough. Since I am mostly OK to deal with electronics affairs and I did some modifications. I added a home made ripple rejection filter to the DC-DC converter in the camera unit. The result is not good enough but I can now see the cylinder as below.


These are not Celsior's but my Honda's which is my sub car.

 

very cool!

 

so the scope records onto a storage unit built in and you can download it via USB? very cool!

 

It is just like a USB camera. You can use it as a cam-corder with a PC. The digital video signal is sent from the camera unit to the USB port. All you need is to record the signal to a hard disk drive in your laptop.

If the S/N (Signal to Noise ratio) were improved, this could be very convenient and useful. The original cheap design and the poor performance were not good enough but adding a filter improved the noise floor to minimize about 10dB or more. But there still remains some noise as you can recognize horizontal lines there. Adding 1 more filter can improve the S/N some more but the size of the head unit (camera unit) becomes too big to use at the spark plug hole. I am now trying to make a small but a better filter.