Dynatron HFC100

[PaulsTV]

Hi there,

I have one of these with a power amp issue, one of the 3055 driver transistors marked as TR14 is listed as being a C11 80. Does anyone have a clue what this may be as google returns nothing. I've uploaded a shot of the board

many thanks

Paul

[julie_m]

Japanese transistor numbers often missed off the initial "2S". So it could be 2SC11 or maybe 2SC1180

[Nickthedentist]

It doesn't look very Japanese to me though.

[G6Tanuki]

That style of encapsulation was developed by Fairchild Semiconductor in the US, and licensed to a range of other manufacturers, some of them Japanese.

I first came across it in the early Fairchild 'μL'-series RTL integrated circuits in the 1960s.

http://semiconductormuseum.com/Museu..._923_Index.htm

Your board also shows the smaller version of this plastic encapsulation (sort-of TO18-size equivalent if your oeiginal-question example is a TO5-size equivalent).

[PaulsTV]

oh boy, it looks like I'm stuck then, there is nothing relating to any of the suggestions you've all made - thanks a lot for the observations though!

Paul

[Nickthedentist]

Originally Posted by G6Tanuki

That style of encapsulation was developed by Fairchild Semiconductor in the US, and licensed to a range of other manufacturers, some of them Japanese.

Thanks for that

[Herald1360]

The 2SC1180 doesn't look like anything special, something like BC547 should sub OK.

[G6Tanuki]

Japanese 2S-style nomenclature started with A and moved on to B before reaching C...

Could be 2SA1180 or 2SB1180 ??

[Biggles]

I'm sure I've seen a couple of transistors with that case style loafing around in a box of bits I have so I will check to see what the numbers are on them. It's a very long shot but they may be the same as yours. If so you can have them free of charge. The fact that they have a little heatsink on them suggests they may be capable of handling a bit of power. (1-2W?)
Alan.

[PaulsTV]

Hi Alan

Yes, they come as pairs - C 11 79 and C 11 80, pnp and npn and directly drive the 2N3055's with approximately 30 or so volts across them - great if you have them, my worry about substitution is that I cannot locate any data on these things - but as suggested, a robust, modern audio transistor could well substitute without too many problems..

thanks

Paul

[Herald1360]

2SC1180 data is in Alltransistors.com. If the 1179 is just PNP complement, then I would expect BC547 BC557 would work fine.

[Nickthedentist]

Does the case style fit in with the data on the site you've found, Chris?

[julie_m]

Depending how much current they are expected to carry, BC337 and BC327 might be a better fit.

[Biggles]

Hi Paul, I've found two transistors but unfortunately one is reading faulty e/b short. The other one is a PNP but the markings are rubbed off. So all I can tell you is that it's a PNP which looks physically the same! Not much help after all.
Alan.

[Radio Wrangler]

With 2N3055 output devices, those devices will just be a complementary pair of PNP and NPN devices used to make up a routine quasi-complementary output stage.

A 60v 1 amp 1 watt device in a TO-5 can should be fine, and you can add a clip on heatsink fin if you're worried.

David

[Herald1360]

Originally Posted by Nickthedentist

Does the case style fit in with the data on the site you've found, Chris?

Yes, it's TO72. (BC107 etc). Does seem a bit small for a 2N3055 driver.....

[Marconi_MPT4]

Hi,
From memory when servicing Dynatron equipment, this device could only be obtained from Dynatron but was probably made by Micro Electronics Ltd. Their devices had characters µɛ prefixing type number.

C1180 is not listed in any of my Micro Electronics data sheets, but cross referencing with Towers International Transistor Selector suggests case outline is X30 with terminal identification L67.

Nearly all Micro Electronics devices with this package style are typically rated at Ic max of 1.2A, power dissipation 3W, bias current 200mA, transition frequency FT 50MHz, but gain (hfe) can vary with type from 20 to 150.

Towers suggest Mullard BD139/140 as a possible substitute but will have to provide some form of heatsink for them.

Hope that helps as a starting point.

Cheers
Rich

[PaulsTV]

Great help, thank you, I think I have enough to go on, there's space for a small heat sink, the only concern might be the gain factor...

I'll report back on results in a day or two, I'll probably mod the other channel power board to match if successful, at least they'll behave the same way.

Paul

[ukcol]

Hello Paul,

I have three MP811-3 transistors that have the same case outline as your transistor.

They test good as NPN silicon transistors and are clearly medium power devices.

There is data for the MP8113 on the net but I'm not convinced it is the same transistor.

I changed a pair of these many years ago (can't remember in what) and the one with short legs is a good pull.

You are welcome to the latter FOC if you PM me with your address. I want to keep the two new ones.

[PaulsTV]

quick update....

thanks to Colin, I now have a working channel again, but with one caveat:

I set the quiescant to match the good channel, both run cool for hours, sounding great, however, on a cold start, the usual heavy thump, but my repaired channel squeals for a short burst, followed by a hum in the associated speaker, and the output pair get seriously hot.

Switching off and on again, clears the problem and system plays without issue.

I have replaced all the electrolytics on the board as a matter of course, any observations welcome...

One point to note, the output pair have a plastic protection cover, the bad channel cover was heat distorted, so looks like an inherited problem, and not a new one.

once again, thanks for your valuable assistance,

Paul