TV Horzontal Output Transistor for output stage..?

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Well, at first I was stunned in silence with mastertech's post. Then, after Duo's post (who I agree with here !!), wondering how old mastertech is.

The obvious technical contect of previous posts in this and other threads makes it difficult to believe mastertech is only trying to help given the tone of the offensive post ...
what is darlington?
you guys dont know huh
darlington is the wiring of two or more trnsistors that increases the overall beta
mr darlington came up with the idea first thus named after him

Please assume that most of us have passed some kind of electronics course until shown otherwise.

-Chris
 
Hi there anatech, nice to see you.

Well, let me get two things off my chest:

First, really, I don't like to argue or fight all that much, I think mastertech and the rest of us probably just had some slight miscommunication here and there which can be worked out.

Second: I don't feel the significance of age in knowledge or experience that much. I understand that there is a connection; however, it's not a perfect connection...

Would you like to take a guess at my age?? I wonder if my answer might surprise you??? :)
 
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Hi Duo,
I'd rather not have a fight either. The tone of the post that upset me wasn't well thought out and seemed a rather young or inexperienced thing to do. I do not have a lasting problem with anyone but had to make a point.

Yes, miscommunications do occur. I've had them. As for your age ... no clue and it does not matter. Maturity matters more.

Bettcha you don't know how old I am. Not that it matters either. If you are young, and well versed in the field, young age can be frustrating as few seem to take you seriously. That much I can say.

I believe that some experience is important before one assumes a certain tone. Not that it will excuse the writer completely. At least there is a body of knowledge the writer is working with. I am not inferring anything here (to avoid insulting anyone).

Anyway, back to the thread.

-Chris
 
Heyyy... I'm 25... :cool: I've friends from far below and above my age.

Luckly.. I find TIP142 & TIP147 complementary darlington pairs in the local market. These devices should perform better than those MJE13005/2N3055/HOTs ..right?

Then contacted a friend of mine (who have a digital camera) to took this pic. Because... The labels on 'ST' make MJE13005s from MOROCCO are LASER carved. The TIPs are also 'ST' make from MOROCCO but the figures are printed instead. Are these fakes...? the pictures shown in http://www.diyaudio.com/forums/showthread.php?s=&threadid=50163 makes more confusion. Do I need the Hammer test to reveal the truth...?
 

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These look real to me. I am no expert on this but I have seen quite a few of these devices and they look like the ones you have here. I bought some TIP141/146 pairs from Mouser and I am not too happy about being gyped. The 146's are from Mospec and they are genuine. But the 141's are fakes. They are so fake that I knew they are fakes the moment I took them out of the pakage. I am not at home right now so I can't show a picture, but this was confirmed because 3 of them died under conditions where they most certainly shouldn't have. None of the 146's failed.
 
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Hi tade,
Those would work okay in a sub amp, but the collector-emitter breakdown is 60 VDC. That means you cannot exceed a bipolar supply of 30 VDC with zero safety margin. Whatever you build, I wouldn't exceed plus and minus 25 VDC for supplies. Real 2N3055 also have very low fT as they were designed for power supply pass transistors. The originals were 19 KHz (yes, you read that correctly). I had to service all kinds of DIY amps in the 1970's made with real 2N3055 transistors. There wasn't one that was high quality. Remember also, these were a commodity part designed to be inexpensive for the industrial market. No thought was ever given to audio service. Later the 2N2955 came out as a compliment to he 2N3055. Still not designed for audio, but many cheap amplifiers were commercially made with these.

Good way to learn how to build an amplifier though, and it will work.
 
NAD used 3055s in a number of their audio amplifiers with no trouble at all. Lower fT just means you need more current at high frequency; thankfully the average power is very small at the top of the band. The 3055 was improved over the years; the late ones being good usually for about 3MHz, some up to 6MHz (I've measured this myself) (RCA SC-15 manual from 1971 specifies fTMin of 800kHz and fhfeMin of 10kHz). Vceo is indeed low, but for a small amplifier or one meant for low impedance loads, this is no problem.

Obviously there are significantly better devices available all over the place, but the 3055 will function in an audio capacity pretty happily :)
 
Thanks for you all contributed this thread. I got unknown number PNP To3 with the inside chip as pic attached. According to TC1 tester there is inside damper diode as analysis. With transistor tester got VCE is around 300-500V and hfe about 150 Vsat(VCE) 1.0xV at 2 amps current(real is around 1.4xx A by DC clamp meter). So I am not sure this is TV Horzontal Output Transistor or not. Just in case that this one can do as output stage of Quasi Complementary amplifier? or any advise please feel free to do so.
 

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Well, I HAVE been designing and commercially building amplifiers since 1969, and 2N3055 was king of the hill and THE industry standard for DECADES.

Armchair "designers" despise them by comparison to 50 year later transistors .... will they build a Time Machine to send these back to the 60´s, 70´s and even early 80´s?
Because these were not available way back then so it´s a ridiculous comparison.

Not designed for cheapness either, they were quite expensive way back then.
70´s couple bucks means 6 bucks today or more.

Sadly had to stop using them in my Guitar/Bass amps around 2008 because market was FLOODED with fakes.
 
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So I am not sure this is TV Horzontal Output Transistor or not.
I've never seen a PNP line output transistor in any make or model (and it used to be the day job) so I would say whatever you have, they are not going to be LOP's Also the current gain of genuine LOP's is typically very very low indeed. Just checked a new BU508A on the tester on my old DVM and it comes in at '10', a TIP41 for comparison shows '94'
 
Thanks for you all contributed this thread. I got unknown number PNP To3 with the inside chip as pic attached. According to TC1 tester there is inside damper diode as analysis. With transistor tester got VCE is around 300-500V and hfe about 150 Vsat(VCE) 1.0xV at 2 amps current(real is around 1.4xx A by DC clamp meter). So I am not sure this is TV Horzontal Output Transistor or not. Just in case that this one can do as output stage of Quasi Complementary amplifier? or any advise please feel free to do so.
Probably just a generic switching transistors. Some types do have free-wheeling diodes in them - darlingtons almost always do, and so do many modern singles intended for off-line SMPS duty. PNP is unusual but not impossible. Probably a one-off that got dumped on the surplus market, making any documentation impossible to find (if there is an NDA, good luck you’d have to know who to bribe). Vce of 500 isn‘t enough for a HOT. Data sheet rating may be much lower, as the useable VCE may be second breakdown limited. Might be only good for 10 mA at 200 V, and if so Vceo wouldn’t be rated higher regardless of where it actually “zeners”. If you are going to try to build an amplifier, hopefully you have a lot of them because the first thing is do is some destructive SOA testing.

PNPs we’re not used for horizontal out except for the few times they experimented with Ge PNPs. Abandoned quickly because you just can’t get the Vceo high enough. Especially not with tin whiskers growing in the cans. Remember that voltage accelerates the process! Those same types were still used for vertical outs, where a 150 volt part will do. One of those horribly overpriced ECG PNP Ge TO-3’s is still billed as a “horizontal out” but I wouldn’t put it in a TV that called for it (and expect the picture not to go out). A lot of people restore old vintage audio, but you don’t see anybody restoring old CRT TVs.
 
Well, I HAVE been designing and commercially building amplifiers since 1969, and 2N3055 was king of the hill and THE industry standard for DECADES

Sadly had to stop using them in my Guitar/Bass amps around 2008 because market was FLOODED with fakes.
But am I correct in assuming that if you had a reliable source of hometaxial 2N3055’s for the foreseeable future, that cost less than $6 apiece you’d do back to using them tomorrow?
 
Most HOTs were only 50 or 60 “watt”. A big one was 100. And that’s the 25 C case temp rating. Of couse the application rarely called for over 5 watts of average dissipation. A 2-volt VCE(sat) compared to 60 volt knee in the 6LG6 helped with that. There really isn’t a LOT of switching loss at 15 KHz.
 
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Without actually looking I seem to recall a figure of around 10 watts for a BU208 which was the industry standard transistor back in the day. Several flatpaks appeared in the later years of CRT TV's such as S2000AF's. The BUT11AF was a popular one in many smaller screen sets. There were some in house marked ones as well. The R4050? in a T03 package comes to mind from old Thorn sets. Never could find anything on that one back in the day.

Dissipation didn't matter much as they were either on or off. The base drive was often from a driver transformer connected between B and E and that gave it a fair old kick (you will turn on :D) and also pulled the base down very quickly on each on/off cycle to give really a fast switch off.