[Premium-Rx] Another HRO-600 component problem

[Gary Geissinger]

Jim,

I did a little analysis looking at the transfer function of a
"dual-emitter" PNP transistor.

I'm not sure yet, but I think you could take a (matched?) pair of 2N2907
transistors, connect the bases, connect the collectors,and wire the
emitters separately.  I'd use pn2907 devices so that you don't have to
worry about shorting the cases.

It might be worth a try.

Also, if you still need the pinout for a 3N111, let me know.  I found it
in an old reference book at home.

73's,

Gary WA0SPM



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-----Original Message-----
From: premium-rx-bounces at ml.skirrow.org
[mailto:premium-rx-bounces at ml.skirrow.org] On Behalf Of James C. Garland
Sent: Wednesday, March 30, 2005 5:46 AM
To: premium-rx at ml.skirrow.org
Subject: [Premium-Rx] Another HRO-600 component problem


Hi Gang,
I'm still plugging away trying to reverse engineer the schematic for my 
HRO-600 synthesizer. One odd component is a 3N111 transistor, which I 
believe to be a PNP dual-emitter transistor designed for chopper 
applications.  I believe it may be bad  (all pins show the same
voltage), 
but I can't find the pinout for it anywhere.  It's a 4-terminal device, 
presumably with a base, collector, emitter-1, and emitter-2.  Anybody
got 
the pin connections and (hopefully) the data sheet for this odd duck.
I've 
never seen dual-emitter transistors before, and am not sure how they're 
used.Tnx!

Jim Garland W8ZR


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