As recommended by John, PD7MAA a drive of 2,5W seems to be ideal for me too. I will now mount a bigger heatsink, 2 fans and a case and then I will do some more measurements. While in the QSO I pushed 5W from the 817 into the amp and with 3 SWR-bars on the dispay and 74W output I killed another pair of IRF530N mosfets. Numbers indicates the output and the numbers in brackets are 'SWR-bars' on the FT-817 display: InputĪfter the 'measurements' I was able to work S57DX on 20m with 60W output (2,5W drive from the FT-817) and I also worked my friend Peter, DC2ZO. diyAudio diyAB Class AB Power Amplifier Build Guide Prepared, written and compiled by JojoD818 Build Guide revision 1.0 for use with diyAB PCB revision 2.0 Introduction: This illustrative build guide has been written to aid anyone in building diyAudio’s diyAB Class AB Power Amplifier, available from the diyAudio Store. this is intended for people living in USA. I did some power output and SWR measurements then. in this video we go over how to wire up and choose the proper switching power supply for your application(8min). After the QRL I soldered them in, and I drilled the holes into two pieces of an old heatsink harvested from an old PC power supply. I ordered a pack of five new IOR IRF530N mosfets on Ebay which arrived today. It took not more than five seconds to kill both FETs while sending an AM carrier (1,5W drive). When I had everything assembled I tested it without a heatsink on the two IRF530N mosfets from IOR.

Building the kit was not too hard, but the surface-mount (SMD) parts are very tiny and you need a calm hand and good eyes.

He does not only have the schematic available, he also shows how nice such DIY-projects can look like.Įspecially the filter is worth a look. While waiting for the kit I found an interesing article from John, PD7MAA on his website. But even if it does not work, the parts alone are worth the money. The kit took only 2,5 weeks to arrive and came in a simple plastic bag without any protection and it also came without a manual or instructions. Some weeks ago I bought a chinese amplifier kit on Ebay which came for 16 Euro / Dollar shipped.

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