开云体育

ctrl + shift + ? for shortcuts
© 2025 开云体育

Sticky Re: What to do when a selftest fails


 

The input capacitor is around 1uF SMT. Hard to get these in high voltage.
Mind you, I would like to see a slightly higher voltage cap used. But I believe the main problem is the breakdown voltage of the protection diodes.
Erik may like to comment.
Regards...Bob VK2ZRE

On 20/02/2025 3:10 am, Terry Perdue via groups.io wrote:
? That is why a DC Block is such an important part of your test kit. It is just a capacitor in series with the centre conductor in an SMA-M to SMA-F adaptor.
Make sure it has a DC rating of at least 100V, preferably 200V. Many of the units on Ebay, etc are only rated at ~20V DC isolation.
HTH Someone...Bob VK2ZRE
With a higher voltage coupling cap, isn’t damage still likely due to the voltage spike as it is connected to a >5V source? I’m sure Erik would have used a higher voltage cap if that weren’t the case.



Join [email protected] to automatically receive all group messages.