Re: G08 part sources?

Well, kinda. The 2N6259 is the superior part and there is no sufficient
replacement - if you want your G08 to work for a while :)

And I quote (or rather cut and paste):

"Rodger Boots had the following to say about the 2N6259 transistors
There is nothing wrong with the 2N6259 and you are going to be hard
pressed to find a better part. Just because the NTE388 LOOKS to be a
better part doesn't tell the whole story. There is not much out there
that has better secondary breakdown characteristics than a 2N6259, but
you will never tell that by looking at just numbers, you need to see a
breakdown chart. This will show you where secondary breakdown is.

For example, looking at the 2N3716 data sheet you will see that at full
voltage (80 volts) the part will withstand 0.2 amps. That is only 16
watts allowed for what is supposed to be a 150-watt part! Compare that
with a 2N6259 that can take 200 watts of dissipation with 90 volts
across the part! It is about a 200-watt part and you can dissipate ALL
OF IT with 90 volts across the part!!! A normal transistor would go into
secondary breakdown (definition: localized melting of the junction due
to current hogging - very destructive) at 20 to 40 volts. There are VERY
few transistors that even come close to what this thing can do.

What kills the 2N6259 is over voltage, plain and simple. The part is
rated for (I think) 125 volts, maybe as high as 150. However, the G08
uses +/-63 volts IDEALLY. So when the amplifier swings to the rail
during a fast vector draw you have close to 125 volts."

tm

"Mills, Lewis" wrote:
>
> Mouser has the 2N6259 for US$7.45
>
> MPSU10 looks like: Vceo=300V, Ic=500mA, hFE@Ic=30mA=30min, fT=60MHz, Pd@25c
> case=10W. You can try an RFQ to American Microsemi
> (http://www.americanmicrosemi.com/cgi-bin/rfqentry.cgi?action=enterrfq&sourc
> e=web&link=141292&query=mpsu10).
> It appears to cross to 2N6558, which crosses to MJE340 or NTE171, both
> available from Mouser.
> Lewis
>
> > -----Original Message-----
> > From: owner-vectorlist@synthcom.com
> > [mailto:owner-vectorlist@synthcom.com]On Behalf Of peter jones
> > Sent: Tuesday, July 16, 2002 3:16 PM
> > To: vectorlist@synthcom.com
> > Subject: Re: VECTOR: G08 part sources?
> >
> >
> >
> > -----Original Message-----
> > From: "Mark Jenison" <jenison@enteract.com>
> > To: <vectorlist@synthcom.com>
> > Date: Wed, 10 Jul 2002 13:51:09 -0400
> > Subject: VECTOR: G08 part sources?
> >
> > >
> > > Hi all,
> > >
> > > Has anyone found sources for the following parts?
> > >
> > > MPSU10/NTE191/ECG191/SK3232
> > > 2N6259
> > > Custom IC 600 (would it be possible to engineer a
> > replacement pcb for this
> > > chip?)
> > >
> > > ...or has someone bought up all these in preparation to
> > release the new and
> > > improved G09! ;-)
> > >
> > > --
> > > Mark Jenison
> > >
> > 1st. please stop quoting NTE / ECG numbers, these are not real parts.
> >
> > MPSU10 - ?2.00 + tax (u.k.)
> > http://www.grandata.co.uk
> >
> > 300v .5amp NPN (if i new the max frequency i could find a
> > modern equiv)
> >
> > i will check on the other stuff.
> >
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Received on Tue Jul 16 14:48:56 2002