Toshiba 2879 transistors

ICECOLDNYC

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Sep 13, 1998, 3:00:00 AM9/13/98

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Simple question....

WHat is the maximum wattage that you have seen from these transistors and at
what volts????
At what point do you think there is a break down???

He who knows not and knows not he knows not,is a fool Shun him
He who knows not and knows he knows not,is simple Teach him
He who knows and knows not he knows,is asleep Awaken him
He who knows and knows that he knows,is wise Follow him
ICECOLDNYC

DB850

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Sep 13, 1998, 3:00:00 AM9/13/98

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this question should be broken down into two questions
what is the most wattage?
what is the most distortion?

Professor

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Sep 13, 1998, 3:00:00 AM9/13/98

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Why don't you plug em in the wall and find out...

ICECOLDNYC wrote in message
<199809131433...@ladder01.news.aol.com>...

CALADAN 1

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Sep 13, 1998, 3:00:00 AM9/13/98

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I have a small base amp with 2 2879's in it. It is swinging to 500 watts.
The amp is built into a 12a pwr supply. The voltage to the finals is 22 .4
volts DC. I hope this helps in some small way to answer your question.
Not the "real" Andy AMR 30 >WHat is the maximum wattage that you have seen from

DB850

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Sep 13, 1998, 3:00:00 AM9/13/98

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what is the voltage with the amp at full out put
i am sure that power supply is not regulated.

Bill Eitner

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Sep 13, 1998, 3:00:00 AM9/13/98

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ICECOLDNYC wrote:
>
> Simple question....

It's not that simple... You're going to get alot of different
answers and personal opinions.

> WHat is the maximum wattage that you have seen from these transistors and at
> what volts????

Reliably: 200 at 14.5 volts. Unreliably: 500 at 25 volts.

> At what point do you think there is a break down???

I believe that anytime you exceed any of the important
breakdown ratings (collector current, collector voltage,
junction temperature, etc.) that the reliability of the
device is reduced to one extent or another. The exact
extent of the reduction in reliability (useful lifetime)
is based on how badly the device is being abused.
--
-------------------------------------------------------------------
-=[Bill Eitner]=-

Link to AM Tutor and rec.radio.cb FAQs:
http://home.earthlink.net/~kd6tas/
-------------------------------------------------------------------

Professor

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Sep 13, 1998, 3:00:00 AM9/13/98

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And you forgot to mention... at 22.4V... it will not last long.

CALADAN 1 wrote in message
<199809132109...@ladder01.news.aol.com>...

>I have a small base amp with 2 2879's in it. It is swinging to 500 watts.
>The amp is built into a 12a pwr supply. The voltage to the finals is 22 .4
>volts DC. I hope this helps in some small way to answer your question.

>Not the "real" Andy AMR 30 >WHat is the maximum wattage that you have seen

tn...@muck.net

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Sep 13, 1998, 3:00:00 AM9/13/98

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On 13 Sep 1998 21:09:49 GMT,in rec.radio.cb you wrote:

>I have a small base amp with 2 2879's in it. It is swinging to 500 watts.
>The amp is built into a 12a pwr supply. The voltage to the finals is 22 .4
>volts DC. I hope this helps in some small way to answer your question.
>Not the "real" Andy AMR 30 >WHat is the maximum wattage that you have seen from
>these transistors and at
>>what volts????
>

It does answer the question.

"Don't touch that box".

You have inadvertently come up with the answer to the energy crunch.
Because of the vast global importance of your discovery, federal
agents will be arriving soon. This is for your own protection! Many
foreign adversaries would just love to get a hold on this box. Don't
sell out. If you play your cards right you may become a
multi-millionaire. Please keep the box in a safe place until the
agents arrive.

ZIP406

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Sep 14, 1998, 3:00:00 AM9/14/98

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they are rated for 120 watts at 13.6 volts but most people keep keying untill
they blow and thats how you find your limit

Sean

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Sep 14, 1998, 3:00:00 AM9/14/98

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Many of the "Gray" brand base amps ran unregulated power supplies
that were well into the low to mid 20's on voltage at idle.
Depending on which transformer it had and the specific
transistors and drive level used, they would "hang out" around 17
to 18 volts under load. As long as the swr is low and severe
overdrive isn't encountered, these units will run for a long
time. Sean aka Bigfoot
>
tn...@muck.net wrote in message
<35fe8b5c...@news3.newscene.com>...

ICECOLDNYC

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Sep 14, 1998, 3:00:00 AM9/14/98

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In article <%dUK1.315$_06.9...@news6.ispnews.com>, "Professor"
<bgri...@kwom.com> writes:

>Why don't you plug em in the wall and find out...

Simpleton!!!!!!!!!!!!

dennis W. Ostrowski

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Sep 14, 1998, 3:00:00 AM9/14/98

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CALADAN 1 wrote:
>
> I have a small base amp with 2 2879's in it. It is swinging to 500 watts.
> The amp is built into a 12a pwr supply. The voltage to the finals is 22 .4
> volts DC. I hope this helps in some small way to answer your question.
> Not the "real" Andy AMR 30 >WHat is the maximum wattage that you have seen from
> these transistors and at
> >what volts????

I would first like to know how you can get 500
watts peak output power, when your 12 amp 22.4
volt power supply can only supply 268 watts of
input power?

The only way I can figure it is if the peaks are
extremely short in duration, the dead key and
quiesent current drain are very low, and the power
supply has a very, very, large filter cap in it!

I wouldn't worry about the 2SC2879 at 22 volts,
but I would but a couple back to back 24 to 26
volt, 5 watt zeners across the secondary
secondary, or better yet a transient suppression
device (TransZorb MOV, etc..) across the
transformer primary, to 'clip' any transient peaks
that could possibly come from your power line...

Dennis

#12

Professor

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Sep 14, 1998, 3:00:00 AM9/14/98

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Hey... ask a stupid question, you get a stupid answer.

ICECOLDNYC wrote in message
<199809141512...@ladder03.news.aol.com>...

Professor

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Sep 14, 1998, 3:00:00 AM9/14/98

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Yes, 500W is a ridiculous figure...

dennis W. Ostrowski wrote in message <35FD31D6...@lucent.com>...

Toll Free

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Sep 14, 1998, 3:00:00 AM9/14/98

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No, actually they are rated for 100 watts

--
Remember.... Technicians make it happen!

Toll Free
http://www.bigradios.com/tollfree
One of the Big Johnson Boys in the Dome!
Every woman likes a man with a great big Johnson!!!

ZIP406 wrote in message <199809140148...@ladder03.news.aol.com>...

ZIP406

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Sep 14, 1998, 3:00:00 AM9/14/98

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I have paper work that says they are rated for 120 watts the 2sc2290 is 100
wtts

10-7

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Sep 14, 1998, 3:00:00 AM9/14/98

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Ohh you got that damn paper work , Watt voltage did that say 120 watts

ZIP406 wrote in message <199809142152...@ladder03.news.aol.com>...

Toll Free

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Sep 14, 1998, 3:00:00 AM9/14/98

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No, it says 100 watts.

I am sending a copy of the data sheet to you via e-mail.

Toll Free

--
Remember.... Technicians make it happen!

Toll Free
http://www.bigradios.com/tollfree
One of the Big Johnson Boys in the Dome!
Every woman likes a man with a great big Johnson!!!

10-7 wrote in message ...

Bill Eitner

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Sep 14, 1998, 3:00:00 AM9/14/98

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ZIP406 wrote:
>
> I have paper work that says they are rated for 120 watts the 2sc2290 is 100
> wtts

As far as Toshiba is concerned, the 2879 is rated at 100
PEP watts and the 2290 is rated at 60 (!) PEP watts at
12.5 volts.

Here's a link you can use to confirm this info:

http://doc.semicon.toshiba.co.jp/docweb3/seek/us/td/16ktran/160019.htm

Bill Eitner

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Sep 14, 1998, 3:00:00 AM9/14/98

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Toll Free wrote:
>
> No, actually they are rated for 100 watts

They are rated at 100 PEP watts at 12.5 volts. There is
no 13.6 volt output wattage specifically stated, but 120
is likely to be pretty close.
=======================================================================

> --
> Remember.... Technicians make it happen!
>
> Toll Free
> http://www.bigradios.com/tollfree
> One of the Big Johnson Boys in the Dome!
> Every woman likes a man with a great big Johnson!!!
>

> ZIP406 wrote in message <199809140148...@ladder03.news.aol.com>...
> >they are rated for 120 watts at 13.6 volts but most people keep keying
> untill
> >they blow and thats how you find your limit

--

dennis W. Ostrowski

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Sep 15, 1998, 3:00:00 AM9/15/98

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Bill Eitner wrote:
>
> Toll Free wrote:
> >
> > No, actually they are rated for 100 watts
>
> They are rated at 100 PEP watts at 12.5 volts. There is
> no 13.6 volt output wattage specifically stated, but 120
> is likely to be pretty close.

--------------------------------------------

Let's do the math:

13.2v - 12.5v = 1.1v (voltage increase)

1.1v X 1.1v = 1.21 (voltage increase squared)

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Sep 16, 1998, 3:00:00 AM9/16/98

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But you are working with a transistor that is being overdriven, clearly out
of it's linear range. Toshiba only rates the transistor linearly to 100
watts, and at about 60 watts with a decent intermod spec.

Toll Free

--
Remember.... Technicians make it happen!

Toll Free
http://www.bigradios.com/tollfree
One of the Big Johnson Boys in the Dome!
Every woman likes a man with a great big Johnson!!!

tn...@muck.net wrote in message <36042832...@news3.newscene.com>...

tn...@muck.net

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Sep 16, 1998, 3:00:00 AM9/16/98

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True. This is just a simple equation and answer. It can be used to
show the relationship between voltage and power in a simple
circuit. It can not be used to show accurate numbers in real circuits.
It only shows the theoretical numbers.

10-7

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Sep 16, 1998, 3:00:00 AM9/16/98

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yes very unreal , I typed it very fast and noticed my error after the
fact but even still the equation wouldnt work

Bill Eitner

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Sep 16, 1998, 3:00:00 AM9/16/98

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Sean wrote:
>
> No, not at all Bill.

Good. It's nice to see that Dennis is active out here
again and has pretty much gotten over the problems he
and I had. I worked hard with him via e-mail in an
effort to square all that away. I'm glad that I didn't
completely alienate you too.

I talk on the newsgroup like I'm talking on the radio.
I deal with e-mail like I'm talking on the phone or with
someone face-to-face. On the phone or face-to-face it's
a serious one-to-one communication. On the newsgroup or
the radio it's a big, loose, party line where anything goes.
There's a big difference. I take care of business on the
phone or in person, and I let it all hang out on the radio.
That's just my way. I'm glad you're able to see it for
what it is.

> I had simply stated that I had never seen
> this transistor rated at 100 watts until relatively recently.
> For years, I had seen distributors and wholesalers selling it as
> a 120 watter.

So had I.

> The only one that I had ever seen call it a 100
> watter was you, and then someone else posted that H & Y also
> referred to it as a 100 watter. That's when I took the time to
> look it up for myself and saw that you were correct, but if the
> voltage curve was followed, their 120 watt rating was also
> correct. Sorry if this wasn't clear.

It was clear. I usually use the 13.6 volt extrapolated
wattage myself when talking about that transistor. In
this thread I decided to take the opportunity to explain
why.

> Thanks for the link.

You're welcome.

> I
> tried to email you last night, but don't know if it went out
> correctly.

It didn't. The last e-mail I got from you was about
the FAQs.

> When I logged on today, it said that I was sending a
> bunch of mail, so who knows what's going on.

Sounds like none of it ever made it to the server.

> I tried sending at
> least 6 times last night and it kept telling me that I was
> disconnected from my server, yet I was still online.

Corrupt ISP sofware is my guess.

I'd like to get with you via e-mail on a few things
for the new FAQs. When you get your e-mail going
(and if you're interested and/or have the time) let
me know.

> Sean Sean
===================================================================

--
-------------------------------------------------------------------

dennis W. Ostrowski

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Sep 16, 1998, 3:00:00 AM9/16/98

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10-7 wrote:
>
> Hey let me try a crack at da maff ,
>
> 20. 6v - 13.6 v = 7v (voltage increase) Lets say I use 20.6
> 7v x 7v = 49 (voltage increase squared)
> 100watts x 49 = 49,000 (predicted resultant power increase)
>
> No wonder i am seeing big numbers , wher did I go wrong in my math ??

No 10-7, I was wrong in my math!

It is the relative change or relative percent of
increase, not the absolute increase that matters.

Instead of 13.2 - 12.5 = 1.1

It should have been 13.2 / 12.5 = 1.056 (the
relative voltage increase)

1.056 X 1.056 = 1.115 (the percentage of increase
squared)

100 watts X 1.115 = 111.5 watts ( the new
predicted power output )

I apologize for the error!

Using your numbers:

20.6 / 13.6 = 1.5147 (the relative voltage
increase)

1.5147 X 1.5147 = 2.2943 ( the percentage of
increase squared )

100 watts X 2.2943 = 229.4 watts ( the new
predicted power output )

I hope these numbers look a little more
legitimate to you now!

Sorry about my error!

Dennis

#12

dennis W. Ostrowski

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Sep 16, 1998, 3:00:00 AM9/16/98

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10-7 wrote:
>
> yes very unreal , I typed it very fast and noticed my error after the
> fact but even still the equation wouldnt work

I apologize for my error.

The number used should be the RELATIVE increase
in voltage, not the ABSOLUTE increase in
voltage....

20.6 / 13.6 = 1.5147

1.5147 X 1.5147 = 2.294

100 watts X 2.294 = 229.4 watts

I hope this number looks a little more realistic
to you.

Dennis

#12

Bill Eitner

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Sep 16, 1998, 3:00:00 AM9/16/98

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dennis W. Ostrowski wrote:
>
> 10-7 wrote:
> >
> > Hey let me try a crack at da maff ,
> >
> > 20. 6v - 13.6 v = 7v (voltage increase) Lets say I use 20.6
> > 7v x 7v = 49 (voltage increase squared)
> > 100watts x 49 = 49,000 (predicted resultant power increase)
> >
> > No wonder i am seeing big numbers , wher did I go wrong in my math ??
>
> No 10-7, I was wrong in my math!
>
> It is the relative change or relative percent of
> increase, not the absolute increase that matters.
>
> Instead of 13.2 - 12.5 = 1.1
>
> It should have been 13.2 / 12.5 = 1.056 (the
> relative voltage increase)
>
> 1.056 X 1.056 = 1.115 (the percentage of increase
> squared)
>
> 100 watts X 1.115 = 111.5 watts ( the new
> predicted power output )
>
> I apologize for the error!

It still comes out pretty close for the original
extrapolation voltage (13.6 volts):

13.6 divided by 12.5 equals 1.088 (the relative voltage
increase)

1.088 times 1.088 equals 1.1837 (the percentage of increase
squared)

100 watts times 1.1837 equals 118.4 watts (the new predicted
power output)

--

dennis W. Ostrowski

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Sep 18, 1998, 3:00:00 AM9/18/98

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Bill Eitner wrote:

>
> dennis W. Ostrowski wrote:
> >
> > I was wrong in my math!
> >
> > It is the relative change or relative percent of
> > increase, not the absolute increase that matters.
> >
> > Instead of 13.2 - 12.5 = 1.1
> >
> > It should have been 13.2 / 12.5 = 1.056 (the
> > relative voltage increase)
> >
> > 1.056 X 1.056 = 1.115 (the percentage of increase
> > squared)
> >
> > 100 watts X 1.115 = 111.5 watts ( the new
> > predicted power output )
> >
> > I apologize for the error!
>
> It still comes out pretty close for the original
> extrapolation voltage (13.6 volts):
>
> 13.6 divided by 12.5 equals 1.088 (the relative voltage
> increase)
>
> 1.088 times 1.088 equals 1.1837 (the percentage of increase
> squared)
>
> 100 watts times 1.1837 equals 118.4 watts (the new predicted
> power output)

.....................................................................................
.....................................................................................
.
.

Good point Bill.

I'm still sorry about the error..

Dennis

#12
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.
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Bill Eitner

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Sep 18, 1998, 3:00:00 AM9/18/98

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13.8 comes out close as well:

13.8 divided by 12.5 equals 1.104 (relative voltage increase)

1.104 times 1.104 equals 1.2188 (relative increase squared)

100 watts times 1.2188 equals 122 watts (the new predicted
power output).
================================================================

--

speedbuggy714

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Sep 19, 1998, 3:00:00 AM9/19/98

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Does anyone think tecnology will advance beyond the 2sc2879? What I mean is
that it has been the largest most powerful and still practical transistor
for the comp. 11 meter amps for quite awhile now. I know about the motorola
50 volt stuff but what I am wondering is if anyone thinks silicon technology
will ever come up with a higher output drop in replacment for the 2sc2879?
Anybody heard anything new on the research lately? I'm sure heat and package
size would be the main problems but still?????

Mike

Toll Free

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Sep 19, 1998, 3:00:00 AM9/19/98

to

Yes,

They are called Ceramic / Steel tubes.

Nobody would run an amplifier that didn't have handles on the tube unless it
was a driver!

Toll Free

--
Remember.... Technicians make it happen!

Toll Free
http://www.bigradios.com/tollfree
One of the Big Johnson Boys in the Dome!
Every woman likes a man with a great big Johnson!!!

speedbuggy714 wrote in message <6tvja0$574$1...@cletus.bright.net>...

PAINKI6669

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Sep 20, 1998, 3:00:00 AM9/20/98

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technology is far more advanced right now thatn you know ..
laterz
"speedbuggy714" <gal...@bright.net> writes:

>Does anyone think tecnology will advance beyond the 2sc2879? What I mean is
>that it has been the largest most powerful and still practical transistor
>for the comp. 11 meter amps for quite awhile now. I know about the motorola
>50 volt stuff but what I am wondering is if anyone thinks silicon technology
>will ever come up with a higher output drop in replacment for the 2sc2879?
>Anybody heard anything new on the research lately? I'm sure heat and package
>size would be the main problems but still?????
>
>Mike

º¿º) § PäìÑKì££êR §
bumpin it:
icecoldnyc
dennis12#
sean
Toll Free
bills2way (bill)
Bill Eitner
Brass
mobil51
toofine79
Palerider
dumbass alone molester list:
Pornfester Molester
bitch ass trick list:
10-7
Co90cchse

ZIP406

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Sep 21, 1998, 3:00:00 AM9/21/98

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I would like to know that too Haven't seen anything better than the 2sc 2879
let me know if you hear anything

jdag...@gate.net

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Sep 22, 1998, 3:00:00 AM9/22/98

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At 12VDC operating voltage NO. The current required for a device to run 250 to
500 watts at 12 VDC will exceed 50 amps. The die will have to be to large and
thus to expensive to manufacture in mass quantities. The only hope is to raise
the operating voltage up. MOSFET technology seems to be leading the way. Though
bipolar devices with operating voltages to 1000 VDC can be made. FET's operate
more like tubes and thus they seem to be leading the way to higher power and
operating voltages. By the early part of next century we should see devices that
can operate at 250 VDC and currents to 5 to 10 amps to frequencies in the low
VHF range. I really think that high power, greater than 250 w, operaing at
voltages of 12VDC is no longer the goal of the semiconductor industry. There is
not enough market for such devives. When I mean enough market, I mean the
demands to make tens of millions of one type per year. The CB market alone can
not generate that kind of business.

Regards
James

On Sat, 19 Sep 1998 02:29:27 -0700, "speedbuggy714" <gal...@bright.net> wrote:

*Does anyone think tecnology will advance beyond the 2sc2879? What I mean is
*that it has been the largest most powerful and still practical transistor
*for the comp. 11 meter amps for quite awhile now. I know about the motorola
*50 volt stuff but what I am wondering is if anyone thinks silicon technology
*will ever come up with a higher output drop in replacment for the 2sc2879?
*Anybody heard anything new on the research lately? I'm sure heat and package
*size would be the main problems but still?????
*
*Mike
*
*
*
*
*

ZIP406

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Sep 22, 1998, 3:00:00 AM9/22/98

to

Thanks for the insight