With 85 to 90% modulation all I have ever seen @13.5 volts is around 280 watts pep on a pair of them.
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I believe it only applies to 60 watts at 12.5 volts and only with their test circuit. Other circuits the transistor could be used in, as well as the collector voltage will effect IMD at a given output level.
After reading all of the above coments the thought that came to me was,i wonder if there might be some sort of vested interest here on the part of those who refuse to believe that they are NOT getting 8 or 900 hundred non harmonic/high swr watts out of their 4 or 5 pill,even more interesting is the question of why people who know better should be so set against an honest airing of views? Who knows, maybe there is a little cash going somewhere?
Well, I'm still waiting for a kickback if any were being passed out. W8JI is probably waiting for his too. Seriously though, no one would waste the time to get 800 watts from four 2SC2879's because the 18 volt electrical system would far outweigh the cost of an 8 transistor amp that could run on 13 volts and make close to that power. You only see hundreds of watts per transistor in large amps where they are pushing the crap out of the transistors. Those that advertise 800 watt 4 "pill" amps are being deceptive at best to their customers who don't know any better.
It is true not many people obtain these power levels from the transistor and it's certainly not the correct way to run the device. Most people assumed this was not possible and that if you made 250 watts from a single 2SC2879 it would be loaded with harmonics and not actual power on the fundamental frequency. In my opinion it has been proved beyond a reasonable doubt that this is possible and W8JI's tests on the spectrum analyzer confirm yet again the harmonic content is only a few percent of total output even without additional filtering.
We like to debate here and sometimes we go overboard and need the help of the moderators to remind us to have control. The debates often lead us to the correct answers to peoples questions. I seriously doubt any of those who have shared information here have received any compensation. What amplifier builders sales benefited from the discussion? I haven't seen a single 11 meter solid state amp that impressed me or that I would recommend someone purchase. Some are better then others but they are all lacking.
I just read EVERY post in this thread. Just sayin'
edit: I also read every post in the QRZ thread. Props to Tom for sharing his experience in that thread.
It was very in depth and informative. Now I am off to build a 8 x 2SC2879 amplifier and only drive it to 100 watts per device 40-50 watts drive power @ 14-16VDC?, with 20 amp collector fuses and protection relays (nice idea Shockwave!) With regulated biasing, I guess at 100ma per device (some help here?), separate bias circuit per pair of transistors, with negative feedback, and I will use an input low pass and output lowpass filter for each band I plan on using it on.
And when I use it on 80-10 meters and tell them it's a homebrew solid state using 2SC2879's and they start barking about IMD, I will DARE their old crotchety asses to bring a spectrum analyzer and $100 cuz they gonna owe me $100 when it checks out clean.
Thanks again for all the discussion. It's what this hobby needs, even if it gets heated at times, it's OK, things do change. People DO use solid state these days, and the precious modern HF rigs DO have a output circuit similar to what's in a Palomar, Texas Star etc, and they CAN be dirtier than your solid state amp, especially the "compact HF All band models" for 12V use. Anyway I'll stop ranting about that. I love the "old" hams, they are a gift to the amateur radio community, with their wealth of knowledge and experience, but the ones that are truly open-minded are the best ones of all. Being a "young" ham is tough on HF sometimes, I suspect that's why a lot of young hams are on 38LSB and 39LSB even though they got their ticket and the equipment. Me personally, I make them get along with me (the old hams), and it usually works out just fine, it's my band(s) too darnit!
edit: I also read every post in the QRZ thread. Props to Tom for sharing his experience in that thread.
It was very in depth and informative. Now I am off to build a 8 x 2SC2879 amplifier and only drive it to 100 watts per device 40-50 watts drive power @ 14-16VDC?, with 20 amp collector fuses and protection relays (nice idea Shockwave!) With regulated biasing, I guess at 100ma per device (some help here?), separate bias circuit per pair of transistors, with negative feedback, and I will use an input low pass and output lowpass filter for each band I plan on using it on.
And when I use it on 80-10 meters and tell them it's a homebrew solid state using 2SC2879's and they start barking about IMD, I will DARE their old crotchety asses to bring a spectrum analyzer and $100 cuz they gonna owe me $100 when it checks out clean.
Thanks again for all the discussion. It's what this hobby needs, even if it gets heated at times, it's OK, things do change. People DO use solid state these days, and the precious modern HF rigs DO have a output circuit similar to what's in a Palomar, Texas Star etc, and they CAN be dirtier than your solid state amp, especially the "compact HF All band models" for 12V use. Anyway I'll stop ranting about that. I love the "old" hams, they are a gift to the amateur radio community, with their wealth of knowledge and experience, but the ones that are truly open-minded are the best ones of all. Being a "young" ham is tough on HF sometimes, I suspect that's why a lot of young hams are on 38LSB and 39LSB even though they got their ticket and the equipment. Me personally, I make them get along with me (the old hams), and it usually works out just fine, it's my band(s) too darnit!
