Just a point of clarification, the BS170 is not driving 50 ohms. There is a transformer in between that reduces the impedance by the square of the turns ratio. And the turns ratio is the ratio of the 50 ohm side of the transformer to the half winding seen by
the BS170. The BS170s will see roughly???of 50 ohms.
Tony
AD0VC
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Dave and I have discussed this at length; there are a large quantity of chewed-up textiles from our discussions. To add to his comments,? his calculation below is based on 50 + 0i? ohms, which is a PURELY RESISTIVE load with
a SWR of 1:1. Even if Z = 50 ohms, you can have V >> 47 V p-p if the load is reactive. If you want to play with the math, try calculating the impedance a 30 ohm resistive with first a 40 ohm inductive reactance then a 40 ohm capacitive reactance........................
Lee KX4TT
On Sunday, July 16, 2023 at 04:02:24 AM EDT, David Birnbaum <dbirnbau@...> wrote:
The relevant voltage is NOT 12V.? The RF voltage is over 40V.? For 5W into 50 ohms the voltage is roughly 47 V p-p.? If the SWR is greater than 1:1 the voltage goes up.? The BS170 has a max voltage of 60V, so it's running near breakdown
dave
k2lyv
