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Ranch55
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I absolutely do not like the transistors that are now produced by HG.
I have not had any good experience with the 2SC2879's, 2SC2290's, or the SD1446's ........
When they do work, they do not work for long.
And this is by using very low drive power (3 watts or less with 10~11 watts PEP).....
Damn, I sure would like for a company to pick up the quality to match the originals of all these ....
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rabbiporkchop
TheRealPorkchop
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That’s odd. Not to contradict you but I’ve built several amps for some guys in the trucking business with those things. They hammer the snot out of them and I haven’t had a complaint yet. We’re talking guys that install them, flip the switch on, break it off and never turn it off again.
Maybe you’ve got a bad batch or maybe I’ve been lucky so far, for my sake I hope it’s been luck and I continue the streak.
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543_Dallas
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A local guy has been building with them and they hold up ok. I've heard the tuning is a bit different but I've never messed with them.
TheRealPorkchop
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I was told the tuning was different but honestly haven’t seen it myself but I’m not a professional amp builder by no means.
I have one guy that shows them no mercy, zero and he’s not had an issue yet. Not to say he won’t but not yet.
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543_Dallas
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I've also heard they bias a bit differently. If I were to build a biased amp with them I would look at idle current vs just putting. 6 or .7 volts on the base. I got away with that with the Toshiba pillz but when I actually checked the current on my 2 pill driver it was pulling 200ma per pill. I left it that way because it was used as a 100 watt driver, had one hell of a fan and was very linear.
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wavrider
W9WDX Amateur Radio Club Member
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I have used them and had no issues, hopefully this continues.
I do order from RF Parts and I DO not buy any off of the auctions sites.
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LeapFrogR
Ranch55
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I never buy off auction site. Always from RF Parts also.
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543_Dallas
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Ranch55 said:
I never buy off auction site. Always from RF Parts also.
What are you using them in? Are you sure there's not a bias or oscillation problem causing them to fail?
Tallman
KW4YJ Honorary Member Silent Key
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Setting the Quiescent current is the most important. A lot of epitaxial transistors run at 100 ma. Check your Specifications or Data sheet.
Eldorado828
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I own a tin man 4 pill with 4 x 2879 HG's and a Texas star with 2 x 2290 HG's both see regular use without any problems for a couple of years now. For me the HG's have served me as well as Toshibas have but that's just my experience. Word through the grapevine was Texas star was going to start using them in the future. Now get me on a dei kick and I can complain there .
Mustang 131
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What would you guys recommend? What brand? I want to fix a 12 pill, but ain't sure it's worth it.
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Ranch55
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Mustang 131 said:
What would you guys recommend? What brand? I want to fix a 12 pill, but ain't sure it's worth it.
Well................
You will get some different opinions from mine, but based on my very top post above, I recommend the original manufacturer's transistors.
If you can find what you need, they will definitely cost more, but the quality is definitely much better.
Now then, if the HG's are compared externally and internally to the original manufacturer transistors, the difference in quality is quite apparent.
The weakest point I have found with the HG's, is the bottom ceramic piece below the tabs are quite thinner and more brittle than the originals. They do not hold the tabs in near as well as the originals, and the tab will break out very easily, even when being as careful as possible.
Makes no matter how folks may feel about the HG's, these are facts about them, not my opinion. Examine them closely, internally and externally. compare with originals.
I know that a point in time will come that no other option will be available for any of them, but until then, the originals is all I will be using.
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Shockwave
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All you need to do is look under the cap of any of these transistors with counterfeit numbers on them to know that no attempt was made to copy the original part number. Simply off the shelf parts that work OK in our application that have been given a much more desirable number stamped on them. None meet the original collector - emitter break down voltages or dissipation ratings.
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rabbiporkchop
9C1Driver
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Mustang 131 said:
What would you guys recommend? What brand? I want to fix a 12 pill, but ain't sure it's worth it.
What is the configuration of this 12 pill? Is it a straight 12 pill or is there a driver stage in there? You really only have two options, go with the original style finals or get the replacement HG finals. Toshiba 2290's and 2879's are very expensive these days, I would only buy them from a known good source.
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Ranch55
Mustang 131
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Its has (2) 2290's driving (12) 2879's. AB biased. Probably.going the 48vdc route for a mobile driver.. Let's embrace the new technology.
Don't think it's worth fixing.
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543_Dallas