Re: Thoughts on Low Power and fewer turns on LP filter toroids

Adrien F4IJA

Just my tests :

I've recently built a 40m QCX+ and it seems to work very well at first try. Anyway, I've measured the RF output power at about 1.8 - 2W with 12.3V, so quite far from the informations in the documentation.

I've winded the toroids as told in the documentation and they were well repartited around the toroids with almost the same gap beetween each turn.

I've made this evening some adjustments by squeezing or expanding the loops around the toroids.

Finally, I can now achieve about 4.2W at 12.3V (so, 2W+ more than before), just by squeezing L2. L1 and L3 are well repartited around their toroids.

Here is the picture :

So, I'm more than happy, and I didn't remove turns. This mod took me only about 5 minutes. So, if you have some RF output issues, it's an idea to try to improve that the simple way.

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