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Texas Star & DEI
- Thread starter GnG8d
- Start date
The DEI devices are just about spot on with Toshiba as far as power out results in Average and Peak readings 
I am only wondering how sturdy or reliable they will be in comparison to Toshiba. Ill post some really cool examples I came across recently.
https://www.youtube.com/watch?v=_u3CKNDXVss
https://www.youtube.com/watch?v=ig5VD_4AoRE
I am only wondering how sturdy or reliable they will be in comparison to Toshiba. Ill post some really cool examples I came across recently.https://www.youtube.com/watch?v=_u3CKNDXVss
https://www.youtube.com/watch?v=ig5VD_4AoRE
They DO work, with a slight reduction in power output to keep acceptable IMD levels. The idle current is a little different, and so is the input and output impedance which seems to be more critical on these new devices in the higher end of their frequency range, such as where most people here are probably trying to run them. With some circuit changes, they work well, however, it seems that Ed, over at Texas Star hasn't figured this out yet, or they just don't care and continue using the same design they have been using for the Toshiba parts.
You have to love all the misinformation about this Chinese transistor. Many sites claim it's a drop in replacement for the 2SC2879. My sources say it's absolutely not. The gains are different so they can't be mixed. It's output is derated by at least 10% and it's collector breakdown voltage is at least 4 volts less than the real part. About the only thing exactly the same is the part number that lies.
Advanced Semiconductor in California purchased the rights to making the real 2SC2879 from Toshiba. The unscrupulous crooks in China do what they always do. Steal other peoples work while placing a counterfeit number on another part. Our government also did what it always does and turned a blind eye allowing just about everything they counterfeit to make it into the US.
It all that "Free Trade" they started stuffing down our throats 15 years ago. It's not free to anyone involved. It's very costly to companies like ASI that invested heavily to bring a real 2SC2879 back into production. It's very profitable for the thieves to invest about an hours worth of time finding the closest transistor they already make and buying a new 2SC2879 rubber stamp and some ink to cheat us.
They made no effort whatsoever to copy the original Toshiba part. If it don't make the same line on the transistor curve tracer to match the original with voltage breakdown or many of the other specifications, it's not a new drop in replacement. It's an old part with a recycled number to maximize profits dishonestly. It's about time we start calling these people out on their lies.
I know I can't buy a new Icom HT for $60 but these idiots think it's OK to glue someone else's name on the cheap box. I know a 2SC2879 doesn't experience a collector emitter breakdown at just over 14 volts and can sustain a 250 watt carrier at over 20 volts before it falls apart like the DEI will.
Advanced Semiconductor in California purchased the rights to making the real 2SC2879 from Toshiba. The unscrupulous crooks in China do what they always do. Steal other peoples work while placing a counterfeit number on another part. Our government also did what it always does and turned a blind eye allowing just about everything they counterfeit to make it into the US.
It all that "Free Trade" they started stuffing down our throats 15 years ago. It's not free to anyone involved. It's very costly to companies like ASI that invested heavily to bring a real 2SC2879 back into production. It's very profitable for the thieves to invest about an hours worth of time finding the closest transistor they already make and buying a new 2SC2879 rubber stamp and some ink to cheat us.
They made no effort whatsoever to copy the original Toshiba part. If it don't make the same line on the transistor curve tracer to match the original with voltage breakdown or many of the other specifications, it's not a new drop in replacement. It's an old part with a recycled number to maximize profits dishonestly. It's about time we start calling these people out on their lies.
I know I can't buy a new Icom HT for $60 but these idiots think it's OK to glue someone else's name on the cheap box. I know a 2SC2879 doesn't experience a collector emitter breakdown at just over 14 volts and can sustain a 250 watt carrier at over 20 volts before it falls apart like the DEI will.
Great post, Shockwave! Here's something you might find interesting too... X-Force is going to the DEI's in their new boxes from what I'm seeing... AND they are selling the DEI's directly off their website as drop-in replacements.
When I first seen the DEI's come out I was thinking that it was almost too good to be true. It makes me glad that my (modified) X-Force 2 x 4 base box I have runs the real goods (Toshiba 2290's and 2879's). Keep us posted if you get more information, and/or you get time to do some experimenting and comparisons.
~Cheers~
When I first seen the DEI's come out I was thinking that it was almost too good to be true. It makes me glad that my (modified) X-Force 2 x 4 base box I have runs the real goods (Toshiba 2290's and 2879's). Keep us posted if you get more information, and/or you get time to do some experimenting and comparisons.
~Cheers~
My connection at RF Parts talked me right out of any thought this was a drop in replacement so I avoided it. I've worked with them since the 1980's and can take their test results as though I did them myself. The results are don't mix them with real ones because the HFE will never match. Drive them below 90% of the original parts rating. Operation above 14 volts is not recommended and results in frequent failures.
The 2SC2879 made by Toshiba can handle 250% of rated drive. It holds up to 22 volts. When properly cooled and matched so it doesn't exceed 25 amps of collector current it can produce over 250 watts per device. Not one of these things are recommended but it says a lot about the Toshiba durability and conservative output ratings. No 12 volt RF bipolar transistor has ever exceeded its 250 watt collector dissipation spec.
One other thing is I can't confirm ASI is even producing the real 2SC2879 today. The sad reality may be these counterfeits have ruined their investment and our possibility of ever seeing another 250 watt RF bipolar.
The 2SC2879 made by Toshiba can handle 250% of rated drive. It holds up to 22 volts. When properly cooled and matched so it doesn't exceed 25 amps of collector current it can produce over 250 watts per device. Not one of these things are recommended but it says a lot about the Toshiba durability and conservative output ratings. No 12 volt RF bipolar transistor has ever exceeded its 250 watt collector dissipation spec.
One other thing is I can't confirm ASI is even producing the real 2SC2879 today. The sad reality may be these counterfeits have ruined their investment and our possibility of ever seeing another 250 watt RF bipolar.
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"If it don't make the same line on the transistor curve tracer to match the original with voltage breakdown or many of the other specifications, it's not a new drop in replacement. It's an old part with a recycled number to maximize profits dishonestly. It's about time we start calling these people out on their lies."
AMEN! Thank you! For one, that is the first thing I noticed. Now, let's check them in a test fixture. They are clearly different. Even input and output impedances are different. How can they say otherwise? Of course it would be affected. VCC, drive, Pout, all affect each other as well as the impedances, not to mention the idle current differences for different IMD ratings.
AMEN! Thank you! For one, that is the first thing I noticed. Now, let's check them in a test fixture. They are clearly different. Even input and output impedances are different. How can they say otherwise? Of course it would be affected. VCC, drive, Pout, all affect each other as well as the impedances, not to mention the idle current differences for different IMD ratings.
Yeah, I just now got this amp converted and tried messing with it. It's doing some really strange things. I have Toshiba devices that I'm thinking of swapping in, or I have some trimmers. Plus I just read the swr/oscillation thread. I haven't decided if it's a tuning issue or if it's trying to oscillate and it could even be a combination I guess. I'm not real happy about it honestly, I just wanted plug/play here.
This is why im going to Mosfets the ERF7530's are beter in ways and i dont like buying china crap even at half the price I would rather support the USA but all the Free trade crap has sent all of Our manifacturers to china where they can get away with sub Par components:thumbdown:.... Its a big slap*Don`t do it* in the face the greedy bastards like walmart are only concerned with profit not perfomance.
The crap they are sending over hear should be taxed high enoughf to equal the price of the USA components then china wouldent owne everything like they do now and we wouldnt be so far in debt .........
With that said they will not sell me any of the china crap<can not stand it> as long as i live and if it comes down to it ill build my owne amps like i already have done useing palomar schematics of there fet amps... If we continue buying that crap why would they not use the cheap china components<can not stand it>.... I have built the 250fet and 450fet and they work perfect and i am now working on a 8 ERF7530 rig of my own m
The crap they are sending over hear should be taxed high enoughf to equal the price of the USA components then china wouldent owne everything like they do now and we wouldnt be so far in debt .........
With that said they will not sell me any of the china crap<can not stand it> as long as i live and if it comes down to it ill build my owne amps like i already have done useing palomar schematics of there fet amps... If we continue buying that crap why would they not use the cheap china components<can not stand it>.... I have built the 250fet and 450fet and they work perfect and i am now working on a 8 ERF7530 rig of my own m
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