In the previous post we’ve gone over the CC-65 probe structure and schematic, and noted a few things that can be done to improve its performance. Other than modifying the probe with higher spec parts, there were a few design decisions and potential issues that were discussed. In this post I plan translate the previous discussion into actual measurements and modifications to the probe. I will cover only part of the circuit in this post, and will cover the rest in a follow up post. This time we’ll have a look at the power-supply and biasing circuit, while the actual amplifier/signal path will be covered in the next post.
I should start by saying that the parts shortage observed nowadays is affecting this project too, it is one of the reasons it took such a long time to get something done. In fact, even now, I’ve had to opt for some replacement parts which weren’t my preferred option, or else it would call for months of wait for parts to be back in stock. With that said, lets move on to some actual measurements.