Kiwi + Lightning
Yesterday we had a strong thunderstorm about 20-30 km away from me.
I was curious how much voltage I would have on the antenna input and attached an oscilloscope. A few times per minute I had spikes above 5V, every 10 minutes or so above 10V and few were off the scale (>50V).
Would that be harmful for the kiwi? In the schematic I've seen 3.3V TVS diodes on the input. If i remember correctly, they can become low impedance, when they're triggered too often, is that correct?
On the other hand there is a nearby kiwi that is on 24/7, even in the strongest thunderstorms and it still works.
I was curious how much voltage I would have on the antenna input and attached an oscilloscope. A few times per minute I had spikes above 5V, every 10 minutes or so above 10V and few were off the scale (>50V).
Would that be harmful for the kiwi? In the schematic I've seen 3.3V TVS diodes on the input. If i remember correctly, they can become low impedance, when they're triggered too often, is that correct?
On the other hand there is a nearby kiwi that is on 24/7, even in the strongest thunderstorms and it still works.
Comments
Nice video. I enjoyed seeing it. It's probably a question of total energy delivered to the diodes, as John suggested.
From a somewhat broader perspective, I think that lightning noise is actually what we all hope to hear with our Kiwis. This because the propagated noise floor is essentially that from world-wide lightning strikes, at least at most places up to near 30 MHz where perhaps galactic noise eventually exceeds it.
Funny, in a way we are trying to optimize the dynamic range of a kiwi system such that it can hear weak lightning while it doesn't get toasted by the strong stuff!
I have an endfed wire, 20m long and 6m above ground.
Could read a newspaper with that LED flashing.