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## Re: [Amps] 160m mosfet linear amplifier problem with ferrite cores

 To: amps , ka4inm@tampabay.rr.com Re: [Amps] 160m mosfet linear amplifier problem with ferrite cores sasas asasas Sat, 17 Apr 2010 06:56:04 -0700 (PDT) mailto:amps@contesting.com>
 ```i mesured the r.f power with digital power/swr meter and it was only 190 W at 106VDC (6A current). The manufacter claims that at 500w output r.f power, at 110vdc, the current is 13A.  So, the efficiency is below 50%. --------------------------------------------------------------------- http://tzitzikas.site90.net (tzitzikas site) http://forum.tzitzikas.site90.net (tzitzikas forum) --------------------------------------------------------------------- --- On Sat, 4/17/10, Ron Youvan wrote: From: Ron Youvan Subject: Re: [Amps] 160m mosfet linear amplifier problem with ferrite cores To: "amps" Date: Saturday, April 17, 2010, 6:24 AM HI  sasas asasas: > Hi, I have constructed this linear amplifier 500w rms (2 kW pep) (50 Ohms) > with 12 mosfet irfp360, http://tzitzikas.webs.com/linear500w.jpg for 160m > band. > When I gave 3 Watts of driving power, it gave to output only 190 W at 106VDC > (6A current). Two radio amateurs who have construct this linear claim tha it > gives 500w > r.f power at 110vdc.    I have been looking at this schematic all week.  I don't get the "500w rms - 2 kW PEP" thing, that doesn't make sense to me.  RMS isn't that different from average and 2 kW PEP is about the same as average. Also, 106 V. X 6 Amps. = 636 Watts at 50% efficiency TPO = 318 Watts is all you should be looking for.  (at this drive level)    The device substitution has possibly reduced the amplifier's gain and efficiency. > But when I tried to give 4 watts of driving r.f power the ferrite Cores (43 > material) > of transformer T3 broken! Which do you think is the problem??    First, type 43 is correct for the HF HAM bands, but I am not sure about the top band. You need to replace the broken core and test it "just for gain" (no more than 2 Watts of drive) at 7 MHz then compare the gain on 160 m. > http://tzitzikas.webs.com/linear20a.JPG > http://tzitzikas.webs.com/ferrite_broken1.JPG > http://tzitzikas.webs.com/ferrite_broken2.JPG    Yup, broke. --     Ron  KA4INM - The next election, I know what is going to happen, I'm going to help. _______________________________________________ Amps mailing list Amps@contesting.com http://lists.contesting.com/mailman/listinfo/amps _______________________________________________ Amps mailing list Amps@contesting.com http://lists.contesting.com/mailman/listinfo/amps ```
 Current Thread [Amps] 160m mosfet linear amplifier problem with ferrite cores, sasas asasas Re: [Amps] 160m mosfet linear amplifier problem with ferrite cores, Ron Youvan Re: [Amps] 160m mosfet linear amplifier problem with ferrite cores, sasas asasas <= Re: [Amps] 160m mosfet linear amplifier problem with ferrite cores, Joe Subich, W4TV Re: [Amps] 160m mosfet linear amplifier problem with ferrite cores, sasas asasas Re: [Amps] 160m mosfet linear amplifier problem with ferrite cores, David Cutter