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Type number of old Ge power transistor

Started by Pimpom January 27, 2017
Reminiscing about old transistors in another thread reminds me of 
something that's been nagging at me on and off for some time.

In the early days of solid-state audio amplifiers - mostly PA 
types - here in India, there was a *very* limited choice of power 
transistors. Most amps used the European Ge TO-3 type AD149. 
Types like the 2N3055 and 2N3773 came long after they were widely 
used in the West.

In between those two 'eras', there was another type that was 
fairly popular for some time, but I've never been able to recall 
the number. All I know is that it was Ge PNP in a TO-3 case, 
JEDEC number (2Nxxxx), 5A Ic max and good gain. I /think/ the 
type number included a 5 and a 2 or 4, but I could be wrong about 
that.

Does anyone have any idea what it might be?
On Friday, January 27, 2017 at 12:01:04 PM UTC-7, Pimpom wrote:
> Reminiscing about old transistors in another thread reminds me of > something that's been nagging at me on and off for some time. > > In the early days of solid-state audio amplifiers - mostly PA > types - here in India, there was a *very* limited choice of power > transistors. Most amps used the European Ge TO-3 type AD149. > Types like the 2N3055 and 2N3773 came long after they were widely > used in the West. > > In between those two 'eras', there was another type that was > fairly popular for some time, but I've never been able to recall > the number. All I know is that it was Ge PNP in a TO-3 case, > JEDEC number (2Nxxxx), 5A Ic max and good gain. I /think/ the > type number included a 5 and a 2 or 4, but I could be wrong about > that. > > Does anyone have any idea what it might be?
2N1546 or 2N1011 maybe?
Pimpom wrote:
> Reminiscing about old transistors in another thread reminds me of > something that's been nagging at me on and off for some time. > > In the early days of solid-state audio amplifiers - mostly PA > types - here in India, there was a *very* limited choice of power > transistors. Most amps used the European Ge TO-3 type AD149. > Types like the 2N3055 and 2N3773 came long after they were widely > used in the West. > > In between those two 'eras', there was another type that was > fairly popular for some time, but I've never been able to recall > the number. All I know is that it was Ge PNP in a TO-3 case, > JEDEC number (2Nxxxx), 5A Ic max and good gain. I /think/ the > type number included a 5 and a 2 or 4, but I could be wrong about > that. > > Does anyone have any idea what it might be?
That was likely the 2N301, a Ge PNP unit in TO-3. It did have pretty good Hfe for a power transistor of that vintage - minimum of 50. I used a couple to build my first solid state guitar amp in the 1960s. See the datasheet at http://www.semicon-data.com/transistor/tc/2n/2N301.html. Cheers, Dave M
On 27/01/2017 19:01, Pimpom wrote:
> Reminiscing about old transistors in another thread reminds me of > something that's been nagging at me on and off for some time. > > In the early days of solid-state audio amplifiers - mostly PA types - > here in India, there was a *very* limited choice of power transistors. > Most amps used the European Ge TO-3 type AD149. Types like the 2N3055 > and 2N3773 came long after they were widely used in the West. > > In between those two 'eras', there was another type that was fairly > popular for some time, but I've never been able to recall the number. > All I know is that it was Ge PNP in a TO-3 case, JEDEC number (2Nxxxx), > 5A Ic max and good gain. I /think/ the type number included a 5 and a 2 > or 4, but I could be wrong about that. > > Does anyone have any idea what it might be?
2N1534 one of family 2N1529-2N1548 - Moderately popular late 1960s to mid 70s? I remember having to replace a pair of 2N1536 AF output in a 16mm film projector in the 1970s (reminded of film projector by your tale in another post). Recently I used a junk box AD149 to switch a house doorbell at 2V and was reminded of how low Vce(sat) in Ge is. Was losing 30mV at 500mA and my junkbox MOSFETs capable of doing that would have needed much higher gate voltages than 2V! What was shocking is how leaky those Ge power devices were. 40-50uA even at room temp. piglet
"piglet" <erichpwagner@hotmail.com> wrote in message 
news:o6hk7b$1vc$1@dont-email.me...
> Recently I used a junk box AD149 to switch a house doorbell at 2V and was > reminded of how low Vce(sat) in Ge is. Was losing 30mV at 500mA and my > junkbox MOSFETs capable of doing that would have needed much higher gate > voltages than 2V! What was shocking is how leaky those Ge power devices > were. 40-50uA even at room temp.
The ~halved bandgap means it's basically the same as silicon operating at double the absolute temperature. Same reason for the very low max operating temp (75 C?), and driftiness in many uses. Drift could be avoided with proper temp-compensating designs, but in the 60s, transistors were still relatively expensive, and designers were still coming out of the toob era! Tim -- Seven Transistor Labs, LLC Electrical Engineering Consultation and Contract Design Website: http://seventransistorlabs.com
On Sat, 28 Jan 2017 00:31:02 +0530, Pimpom <Pimpom@invalid.com> wrote:

>Reminiscing about old transistors in another thread reminds me of >something that's been nagging at me on and off for some time. > >In the early days of solid-state audio amplifiers - mostly PA >types - here in India, there was a *very* limited choice of power >transistors. Most amps used the European Ge TO-3 type AD149. >Types like the 2N3055 and 2N3773 came long after they were widely >used in the West. > >In between those two 'eras', there was another type that was >fairly popular for some time, but I've never been able to recall >the number. All I know is that it was Ge PNP in a TO-3 case, >JEDEC number (2Nxxxx), 5A Ic max and good gain. I /think/ the >type number included a 5 and a 2 or 4, but I could be wrong about >that. > >Does anyone have any idea what it might be?
My first transistorized audio power amplifier used a Delco DS501 "door-knob" device, class-A, ~5W... ~1957-58 I remember the date range because I began dating my wife-to-be on October 7, 1957, and her father, a machine shop operator, machined me a heat-sink. ;-) ...Jim Thompson -- | James E.Thompson | mens | | Analog Innovations | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | STV, Queen Creek, AZ 85142 Skype: skypeanalog | | | Voice:(480)460-2350 Fax: Available upon request | Brass Rat | | E-mail Icon at http://www.analog-innovations.com | 1962 | I'm looking for work... see my website. Thinking outside the box... elegant solutions.
On 1/28/2017 1:27 AM, DemonicTubes wrote:
> On Friday, January 27, 2017 at 12:01:04 PM UTC-7, Pimpom wrote: >> Reminiscing about old transistors in another thread reminds me of >> something that's been nagging at me on and off for some time. >> >> In the early days of solid-state audio amplifiers - mostly PA >> types - here in India, there was a *very* limited choice of power >> transistors. Most amps used the European Ge TO-3 type AD149. >> Types like the 2N3055 and 2N3773 came long after they were widely >> used in the West. >> >> In between those two 'eras', there was another type that was >> fairly popular for some time, but I've never been able to recall >> the number. All I know is that it was Ge PNP in a TO-3 case, >> JEDEC number (2Nxxxx), 5A Ic max and good gain. I /think/ the >> type number included a 5 and a 2 or 4, but I could be wrong about >> that. >> >> Does anyone have any idea what it might be? > > 2N1546 or 2N1011 maybe? >
I don't think so. 2N1546 - Ic(max) too high 2N1011 - specs look about right, but the type number doesn't.
On 1/28/2017 2:32 AM, Dave M wrote:
> Pimpom wrote: >> Reminiscing about old transistors in another thread reminds me of >> something that's been nagging at me on and off for some time. >> >> In the early days of solid-state audio amplifiers - mostly PA >> types - here in India, there was a *very* limited choice of power >> transistors. Most amps used the European Ge TO-3 type AD149. >> Types like the 2N3055 and 2N3773 came long after they were widely >> used in the West. >> >> In between those two 'eras', there was another type that was >> fairly popular for some time, but I've never been able to recall >> the number. All I know is that it was Ge PNP in a TO-3 case, >> JEDEC number (2Nxxxx), 5A Ic max and good gain. I /think/ the >> type number included a 5 and a 2 or 4, but I could be wrong about >> that. >> >> Does anyone have any idea what it might be? > > > > That was likely the 2N301, a Ge PNP unit in TO-3. It did have pretty good > Hfe for a power transistor of that vintage - minimum of 50. I used a couple > to build my first solid state guitar amp in the 1960s. > See the datasheet at > http://www.semicon-data.com/transistor/tc/2n/2N301.html. >
Ic(max) of 3A is too low, and I'm sure the type number had four digits.
On Sat, 28 Jan 2017 07:53:55 -0700, Jim Thompson
<To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> wrote:

>On Sat, 28 Jan 2017 00:31:02 +0530, Pimpom <Pimpom@invalid.com> wrote: > >>Reminiscing about old transistors in another thread reminds me of >>something that's been nagging at me on and off for some time. >> >>In the early days of solid-state audio amplifiers - mostly PA >>types - here in India, there was a *very* limited choice of power >>transistors. Most amps used the European Ge TO-3 type AD149. >>Types like the 2N3055 and 2N3773 came long after they were widely >>used in the West. >> >>In between those two 'eras', there was another type that was >>fairly popular for some time, but I've never been able to recall >>the number. All I know is that it was Ge PNP in a TO-3 case, >>JEDEC number (2Nxxxx), 5A Ic max and good gain. I /think/ the >>type number included a 5 and a 2 or 4, but I could be wrong about >>that. >> >>Does anyone have any idea what it might be? > >My first transistorized audio power amplifier used a Delco DS501 >"door-knob" device, class-A, ~5W... ~1957-58 > >I remember the date range because I began dating my wife-to-be on >October 7, 1957, and her father, a machine shop operator, machined me >a heat-sink. ;-) > > ...Jim Thompson
My first job interview, I said that I preferred tubes for my personal stuff, because transistors were expensive and easy to blow up. The guy sniffed and said "that won't do" and dismissed me. The next guy laughed and hired me, and I designed $200 million worth of stuff for him. Really, germanium transistors weren't very rugged or reliable. The first good transistors were the Fairchild silicon planars. Early plastic-packaged digital ICs - RTL, DTL, early TTL - were pretty bad, too. Hardly anything fails nowadays. -- John Larkin Highland Technology, Inc lunatic fringe electronics
On Sat, 28 Jan 2017 09:01:17 -0800, John Larkin
<jjlarkin@highlandtechnology.com> wrote:

>On Sat, 28 Jan 2017 07:53:55 -0700, Jim Thompson ><To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> wrote: > >>On Sat, 28 Jan 2017 00:31:02 +0530, Pimpom <Pimpom@invalid.com> wrote: >> >>>Reminiscing about old transistors in another thread reminds me of >>>something that's been nagging at me on and off for some time. >>> >>>In the early days of solid-state audio amplifiers - mostly PA >>>types - here in India, there was a *very* limited choice of power >>>transistors. Most amps used the European Ge TO-3 type AD149. >>>Types like the 2N3055 and 2N3773 came long after they were widely >>>used in the West. >>> >>>In between those two 'eras', there was another type that was >>>fairly popular for some time, but I've never been able to recall >>>the number. All I know is that it was Ge PNP in a TO-3 case, >>>JEDEC number (2Nxxxx), 5A Ic max and good gain. I /think/ the >>>type number included a 5 and a 2 or 4, but I could be wrong about >>>that. >>> >>>Does anyone have any idea what it might be? >> >>My first transistorized audio power amplifier used a Delco DS501 >>"door-knob" device, class-A, ~5W... ~1957-58 >> >>I remember the date range because I began dating my wife-to-be on >>October 7, 1957, and her father, a machine shop operator, machined me >>a heat-sink. ;-) >> >> ...Jim Thompson > >My first job interview, I said that I preferred tubes for my personal >stuff, because transistors were expensive and easy to blow up. The guy >sniffed and said "that won't do" and dismissed me. The next guy >laughed and hired me, and I designed $200 million worth of stuff for >him. > >Really, germanium transistors weren't very rugged or reliable. The >first good transistors were the Fairchild silicon planars. > >Early plastic-packaged digital ICs - RTL, DTL, early TTL - were pretty >bad, too. Hardly anything fails nowadays.
The Delco DS501 was used successfully in the automotive environment. Did you miss the door-knob packaging part? Early plastic (phenolic) package chemistry ate the Aluminum metalization. ...Jim Thompson -- | James E.Thompson | mens | | Analog Innovations | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | STV, Queen Creek, AZ 85142 Skype: skypeanalog | | | Voice:(480)460-2350 Fax: Available upon request | Brass Rat | | E-mail Icon at http://www.analog-innovations.com | 1962 | I'm looking for work... see my website. Thinking outside the box... elegant solutions.