On Sun, Apr 13, 2025 at 10:42 AM, dl8lrz Reiner wrote:
The best results were achieved with 2 additional BS170. (A BS170 can switch about 380-550mA, depending on the manufacturer; with more, the residual drain voltage (and heat) increases significantly. Disadvantage: The higher capacitances can detune the LPF, and this non-linearly. The 20-17-15m filter (and higher) in particular can cause a lot of trouble afterward.
Reiner,
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Yes, the easiast way I found so far is to use 2 x 3 BS170's instead of 2 x 2.
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I carefully checked the LPF sweeps on all bands before and after mounting the extra 2 BS170's.
No change is obvious from 160 through 40M and on the higher bands the changes are small.
Some bands look even a bit better and no change is needed at all.
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My build is a rev1 board set up for 9V, using a WTST on a BN-43-302 core.
The beauty of a 9V build is that you can test is more safely with a higher supply voltage.
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Going for maximum smoke, 12V deliveres this:
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160M
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