I would like advice on a new 2200/630m amplifier that I have built. It works but exhibits two problems. It uses a pair of APT5023 mosfets, 48Vdc supply, output transformer 3T:6T on a pair of 26mm typ
I would like advice on a new 2200/630m amplifier that I have built. It works but exhibits two problems. It uses a pair of APT5023 mosfets, 48Vdc supply, output transformer 3T:6T on a pair of 26mm typ
Hello Manfred, Thank you very much for the quick and very informative reply. I will follow your advice and work on eliminating the turn-on transient. There are 56 Ohm gate resistors and a small amoun
Manfred, Thank you for the helpful followup. I will try lower value gate resistors. That will also have the advantage that I will be able to drive to higher output on 160 I think. (My 1W drive is not
Thank you very much Manfred. Your notes have wonderful technical information. I have learned a lot from this correspondence. You have provided an excellent design tutorial! I will lower the series ga
Manfred, the distorted waveform output (observed before at amp output when driving the antenna either with or without a T form LPF) is fixed. Thank you for suggesting using a Pi form LPF. When I buil
Thanks for the info Jim. This amp project has been a fun learning experience. I appreciate all the help I have gotten along the way from more experienced guys. 73, Roger . ___________________________
Hello Jim, It was nice to hear from you. I have really enjoyed and utilized your A Ham's Guide to RFI, Ferrites, Baluns, and Audio Interfacing. It is a great resource. Thanks for making that availabl
Hello Jim, Nice to hear from you again. The transmission line balun that I made for the amp, as mentioned in a previous post, was 5T of bifilar wire around an unknown (grey) toroid that resulted in 2
Angel, Manfred may reply for himself, but from one of his webpages https://ludens.cl/Electron/mosfetamps/amps.html <https://ludens.cl/Electron/mosfetamps/amps.html> his analysis of the circuit shows