5w PA Kit and SWR (IRF510 or RD15HVF1/RD16HHF1)

Roney Monte

Hello, I'm going to build my second 5W PA Kit, this time for low bands (80m, 40m and maybe 160m).

I need to know how the IRF510 handles SWR ?

I remember from BS170 and a "random wire" there were not much problem about SWR by it's low potency. But I do not know what happens at 5 watts or more.

I tried to read the IRF510 datasheet and found no information about it. I read also the RH15HVF and the RD16HHF transistors, and found the following information :

Load VSWR tolerance VDD=15.2V,Po=16W(Pin Control), f=30MHz (or 175MHz),Idq=0.5A,Zg=50ohm, Load VSWR=20:1(All Phase) -> No destroy

I don't know how to interpret technically, but it seems to handle SWR to 20:1 with no problem. Am I right ? Is better to use the RD transistors than IRF510 in the aspect of handling SWR ?

I just want to use the same antenna (like a 1/4wave as same as 1/2 wave, and maybe 1/8 ware) dipole for 80m and 40m and maybe 160m, and it will have different SWR at different bands.

Roney PY1ZB

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