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Sci.Electronics.Basics -> What Germanium PNP transistor do I use?
There are 46 messages in this thread.
You are currently looking at messages 20 to 40.
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Author: ian fieldDate: 12:13 17-03-07
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"Michael Black" <et472@FreeNet.Carleton.CA> wrote in message
news:etgtii$rih$1@theodyn.ncf.ca...
> I thought people talked about power germaniums still being made and used.
> The talk would have been in one of the sci.electronics.* newsgroups
> sometime
> in the past decade, but that's the best I can provide as a pointer.
>
> Michael
>
Way back in the early days when silicon devices were new, I often wondered -
if silicon is so good, why is germanium still used in the power stages of
radios that have silicon RF/IF stages?
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Author: JoergDate: 14:24 17-03-07
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ian field wrote:
> "Michael Black" <et472@FreeNet.Carleton.CA> wrote in message
> news:etgtii$rih$1@theodyn.ncf.ca...
>
>
>>I thought people talked about power germaniums still being made and used.
>>The talk would have been in one of the sci.electronics.* newsgroups
>>sometime
>>in the past decade, but that's the best I can provide as a pointer.
>>
>> Michael
>>
>
>
> Way back in the early days when silicon devices were new, I often wondered -
> if silicon is so good, why is germanium still used in the power stages of
> radios that have silicon RF/IF stages?
>
Old rule: As long as Ge was only one cent less than Si, they'd use Ge.
Maybe the fact that many cars were still equipped with 6V systems also
favored Ge.
--
Regards, Joerg
http://www.analogconsultants.com
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Author: ian fieldDate: 15:13 17-03-07
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"Joerg" <notthisjoergsch@removethispacbell.net> wrote in message
news:bnWKh.13743$FG1.5206@newssvr27.news.prodigy.net...
> ian field wrote:
>
>> "Michael Black" <et472@FreeNet.Carleton.CA> wrote in message
>> news:etgtii$rih$1@theodyn.ncf.ca...
>>
>>
>>>I thought people talked about power germaniums still being made and used.
>>>The talk would have been in one of the sci.electronics.* newsgroups
>>>sometime
>>>in the past decade, but that's the best I can provide as a pointer.
>>>
>>> Michael
>>>
>>
>>
>> Way back in the early days when silicon devices were new, I often
>> wondered - if silicon is so good, why is germanium still used in the
>> power stages of radios that have silicon RF/IF stages?
>
> Old rule: As long as Ge was only one cent less than Si, they'd use Ge.
> Maybe the fact that many cars were still equipped with 6V systems also
> favored Ge.
The 12V auto-electrics were well and truly established in the period I
remember, and don't forget the first ever transistor radio used a 22-1/2V
(tube) hearing aid battery - presumably the PP3 hadn't been invented yet.
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Author: JoergDate: 15:14 17-03-07
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Michael Black wrote:
> Joerg (notthisjoergsch@removethispacbell.net) writes:
>
>
>>>You don't.
>>>
>>
>>That's right, unless it's hobby and there are tons of them in the box.
>>My favorites were AC127 for audio, AF126 up to FM band, and AF239 for
>>the really hot stuff.
>>
>>
>
> But otherwise, it's a question like "where do I get a tunnel diode, I want
> to build this circuit I found in a book or on the internet...". And the
> poster doesn't realize how old the schematic is, or that tunnel diodes
> at their best were mostly a novelty (with some real exceptions) and for
> the hobbyist lasted about a decade (to stretch things a bit).
>
> In order to stick with the circuit, they will have to work really hard to
> find a tunnel diode, and may pay good money for it. And before that,
> they really should evaluate why they want to make that circuit. IN most
> cases, it's because they don't know better (because they want to build
> something simple, and it certainly is a simple circuit).
>
As a kid I always laughed when I saw yet another circuit proposal with a
tunnel diode or a UJT. None of the stores had any, not even the big ones
in large cities. Looked like someone just had to publish it to show off.
I built my oscillators with scavenged AF139/239. Or sometimes tubes.
>
>>>The only reason you'd use a germanium transistor at this time is if
>>>there was a specific reason for using germanium. There are still some
>>>things where germanium transistors can be useful, which is why some
>>>are still being manufactured, ...
>>
>>
>>Where? Where? <drool>
>>
> I thought people talked about power germaniums still being made and used.
> The talk would have been in one of the sci.electronics.* newsgroups sometime
> in the past decade, but that's the best I can provide as a pointer.
>
Most of what people thinks is fresh production is in reality just old
stock. When it's gone it's gone, plus they often want top Dollar.
--
Regards, Joerg
http://www.analogconsultants.com
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Author: ian fieldDate: 15:34 17-03-07
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"Joerg" <notthisjoergsch@removethispacbell.net> wrote in message
news:7dWKh.5529$tv6.5086@newssvr19.news.prodigy.net...
> As a kid I always laughed when I saw yet another circuit proposal with a
> tunnel diode or a UJT. None of the stores had any, not even the big ones
> in large cities. Looked like someone just had to publish it to show off. I
> built my oscillators with scavenged AF139/239. Or sometimes tubes.
A few years ago I had a project published in Television Magazine which was
loosely based on a Programmable Unijunction Transistor (PUT).
The project met the need for testing opto-couplers that did not offer an
electrical connection to the photo-transistor's base terminal making the
usual "diode" tests impossible, this required a cheap simple and minimum
parts count pulse generator to drive the LED, granted regular UJTs are very
rare these days so initially I looked at the PUT which is basically a
thyristor with a negative (anode end) gate, my first thought is that an SCS
(silicon controlled switch) - a 4-layer thyristor device with both gates
available would be relatively easy for a TV engineer to obtain, and failing
that, one can be constructed easily with a complementary pair of small
signal transistors.
However as I looked at the circuit - and the complementary asymmetry of the
4-layer device, I realised that it was possible to turn the circuit upside
down and use a small TO-92 thyristor to the same effect. Thyristors of this
type are quite common in TV & monitor PSUs - not least as safety trip
devices, so almost by accident the project became a dual purpose component
tester.
Don't be too hasty to count out the tunnel diode - according the manual, the
Tek465 scope contains a couple of them.
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Author: Rich GriseDate: 17:27 17-03-07
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On Sat, 17 Mar 2007 14:22:10 +0000, Michael Black wrote:
> Joerg (notthisjoergsch@removethispacbell.net) writes:
>
>>> You don't.
>>
>> That's right, unless it's hobby and there are tons of them in the box.
>> My favorites were AC127 for audio, AF126 up to FM band, and AF239 for
>> the really hot stuff.
>>
>>
> But otherwise, it's a question like "where do I get a tunnel diode, I want
> to build this circuit I found in a book or on the internet...". And the
> poster doesn't realize how old the schematic is, or that tunnel diodes
> at their best were mostly a novelty (with some real exceptions) and for
> the hobbyist lasted about a decade (to stretch things a bit).
>
> In order to stick with the circuit, they will have to work really hard to
> find a tunnel diode, and may pay good money for it. And before that,
> they really should evaluate why they want to make that circuit. IN most
> cases, it's because they don't know better (because they want to build
> something simple, and it certainly is a simple circuit).
>
>>> The only reason you'd use a germanium transistor at this time is if
>>> there was a specific reason for using germanium. There are still some
>>> things where germanium transistors can be useful, which is why some
>>> are still being manufactured, ...
>>
>> Where? Where? <drool>
>>
> I thought people talked about power germaniums still being made and used.
> The talk would have been in one of the sci.electronics.* newsgroups sometime
> in the past decade, but that's the best I can provide as a pointer.
Apparently, they're available _SOME_where - at least the audiophools seem
to think so:
http://www.chandlerlimited.com/products/germanium_tceq.php
(although, a glance at the price tag kinda makes me think they've set
up their own custom fab line or something ;-) )
Are schottkys not good enough?
Cheers!
Rich
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Author: Rich GriseDate: 17:30 17-03-07
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On Sat, 17 Mar 2007 16:13:40 +0000, ian field wrote:
> "Michael Black" <et472@FreeNet.Carleton.CA> wrote in message
>
>> I thought people talked about power germaniums still being made and used.
>> The talk would have been in one of the sci.electronics.* newsgroups
>> sometime
>> in the past decade, but that's the best I can provide as a pointer.
>
> Way back in the early days when silicon devices were new, I often wondered -
> if silicon is so good, why is germanium still used in the power stages of
> radios that have silicon RF/IF stages?
At the time, Ge was the only way that they could make cost-effective
power PNPs. They still had some bugs to work out with making high-power
Si PNPs. (they've apparently figured it out sometime in the last 30
years or so, however. ;-) )
Hope This Helps!
Rich
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Author: Michael BlackDate: 17:37 17-03-07
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"ian field" (dai.ode@ntlworld.com) writes:
> "Michael Black" <et472@FreeNet.Carleton.CA> wrote in message
> news:etgtii$rih$1@theodyn.ncf.ca...
>
>> I thought people talked about power germaniums still being made and used.
>> The talk would have been in one of the sci.electronics.* newsgroups
>> sometime
>> in the past decade, but that's the best I can provide as a pointer.
>>
>> Michael
>>
>
> Way back in the early days when silicon devices were new, I often wondered -
> if silicon is so good, why is germanium still used in the power stages of
> radios that have silicon RF/IF stages?
>
>
I thought that was due to the curve of a new device. Transistors started
out as being good for not much more than audio, and low power at that.
They worked at it, until there were better frequency capability and they
could actually build audio output amplifiers out of the transistors. Witness
all those hybrid radios (not just car, but there were early lunchbox style
walkie talkies that were hybrid), where the audio stages were transistorized
and maybe some of the lower frequency stages, while tubes remained in
most of the radio stages.
Silicon came along, and they had to start all over, working at improving
their frequency range and power capability (though likely the curve wasn't
as slow since they'd practiced on germanium). By then, they could make
fully transistorized radios, but not always with silicon.
Look at the early transistor audio amplifiers, and they were basically
copies of tube amplifiers, ie transformer or RC coupled, with an output
transformer. A few years later, they were DC coupled, and depending
on the design may not have even had a coupling capacitor at the output.
Michael
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Author: ian fieldDate: 17:40 17-03-07
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"Rich Grise" <rich@example.net> wrote in message
news:pan.2007.03.17.21.31.13.358992@example.net...
> On Sat, 17 Mar 2007 16:13:40 +0000, ian field wrote:
>> "Michael Black" <et472@FreeNet.Carleton.CA> wrote in message
>>
>>> I thought people talked about power germaniums still being made and
>>> used.
>>> The talk would have been in one of the sci.electronics.* newsgroups
>>> sometime
>>> in the past decade, but that's the best I can provide as a pointer.
>>
>> Way back in the early days when silicon devices were new, I often
>> wondered -
>> if silicon is so good, why is germanium still used in the power stages of
>> radios that have silicon RF/IF stages?
>
> At the time, Ge was the only way that they could make cost-effective
> power PNPs. They still had some bugs to work out with making high-power
> Si PNPs. (they've apparently figured it out sometime in the last 30
> years or so, however. ;-) )
>
> Hope This Helps!
> Rich
>
In the period I'm thinking of transformer coupled O/P stages still hadn't
been completely outdated by complementary pairs so they could have chosen
whichever polarity suited best - it just seemed to take a while to develop
silicon transistors that could supersede germanium in power stages.
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Author: Michael BlackDate: 17:47 17-03-07
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"ian field" (dai.ode@ntlworld.com) writes:
> "Joerg" <notthisjoergsch@removethispacbell.net> wrote in message
> news:7dWKh.5529$tv6.5086@newssvr19.news.prodigy.net...
>
>
>> As a kid I always laughed when I saw yet another circuit proposal with a
>> tunnel diode or a UJT. None of the stores had any, not even the big ones
>> in large cities. Looked like someone just had to publish it to show off. I
>> built my oscillators with scavenged AF139/239. Or sometimes tubes.
>
> A few years ago I had a project published in Television Magazine which was
> loosely based on a Programmable Unijunction Transistor (PUT).
>
> The project met the need for testing opto-couplers that did not offer an
> electrical connection to the photo-transistor's base terminal making the
> usual "diode" tests impossible, this required a cheap simple and minimum
> parts count pulse generator to drive the LED, granted regular UJTs are very
> rare these days so initially I looked at the PUT which is basically a
> thyristor with a negative (anode end) gate, my first thought is that an SCS
> (silicon controlled switch) - a 4-layer thyristor device with both gates
> available would be relatively easy for a TV engineer to obtain, and failing
> that, one can be constructed easily with a complementary pair of small
> signal transistors.
>
> However as I looked at the circuit - and the complementary asymmetry of the
> 4-layer device, I realised that it was possible to turn the circuit upside
> down and use a small TO-92 thyristor to the same effect. Thyristors of this
> type are quite common in TV & monitor PSUs - not least as safety trip
> devices, so almost by accident the project became a dual purpose component
> tester.
>
> Don't be too hasty to count out the tunnel diode - according the manual, the
> Tek465 scope contains a couple of them.
>
>
But that was one of the exceptions. IN the hobby realm, they were a novelty
and nothing that was published could not be done with some other device.
In that scope, it's either in the trigger system, or it's generating a pulse
(I forget, though I know at some point I did read what the tunnel diode
was doing).
ANd yes, if you needed to replace that tunnel diode, you'd need a tunnel
diode. But, even for that, there seems to be a fair consensus that getting
a tunnel diode at this point would require effort at the very least.
Michael
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Author: Michael BlackDate: 17:51 17-03-07
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"ian field" (dai.ode@ntlworld.com) writes:
> In the period I'm thinking of transformer coupled O/P stages still hadn't
> been completely outdated by complementary pairs so they could have chosen
> whichever polarity suited best - it just seemed to take a while to develop
> silicon transistors that could supersede germanium in power stages.
>
>
There may have even been some chasm to leap to NPN. So many of the early
circuits did use PNP transistors that one might suspect there was some
problem in making NPN. But perhaps it was just lethargy, they started out
with PNP and kept with them up to a certain point. Or those positive
ground cars made PNP a better choice at the time.
Michael
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Author: JoergDate: 18:28 17-03-07
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ian field wrote:
> "Joerg" <notthisjoergsch@removethispacbell.net> wrote in message
> news:bnWKh.13743$FG1.5206@newssvr27.news.prodigy.net...
>
>>ian field wrote:
>>
>>
>>>"Michael Black" <et472@FreeNet.Carleton.CA> wrote in message
>>>news:etgtii$rih$1@theodyn.ncf.ca...
>>>
>>>
>>>
>>>>I thought people talked about power germaniums still being made and
used.
>>>>The talk would have been in one of the sci.electronics.* newsgroups
>>>>sometime
>>>>in the past decade, but that's the best I can provide as a pointer.
>>>>
>>>> Michael
>>>>
>>>
>>>
>>>Way back in the early days when silicon devices were new, I often
>>>wondered - if silicon is so good, why is germanium still used in the
>>>power stages of radios that have silicon RF/IF stages?
>>
>>Old rule: As long as Ge was only one cent less than Si, they'd use Ge.
>>Maybe the fact that many cars were still equipped with 6V systems also
>>favored Ge.
>
>
> The 12V auto-electrics were well and truly established in the period I
> remember, and don't forget the first ever transistor radio used a 22-1/2V
> (tube) hearing aid battery - presumably the PP3 hadn't been invented yet.
>
Then you must be young. My first car was built in 1969 (I got it around
1980). A Citroen 2CV, 6V electrics all through out. Number of electronic
components in that car before installing the radio with its Ge
transistors: Zilch. Not even a diode.
--
Regards, Joerg
http://www.analogconsultants.com
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Author: JoergDate: 18:32 17-03-07
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Michael Black wrote:
> "ian field" (dai.ode@ntlworld.com) writes:
>
>>"Joerg" <notthisjoergsch@removethispacbell.net> wrote in message
>>news:7dWKh.5529$tv6.5086@newssvr19.news.prodigy.net...
>>
>>
>>
>>>As a kid I always laughed when I saw yet another circuit proposal with a
>>>tunnel diode or a UJT. None of the stores had any, not even the big ones
>>>in large cities. Looked like someone just had to publish it to show off. I
>>>built my oscillators with scavenged AF139/239. Or sometimes tubes.
>>
>>A few years ago I had a project published in Television Magazine which was
>>loosely based on a Programmable Unijunction Transistor (PUT).
>>
>>The project met the need for testing opto-couplers that did not offer an
>>electrical connection to the photo-transistor's base terminal making the
>>usual "diode" tests impossible, this required a cheap simple and
minimum
>>parts count pulse generator to drive the LED, granted regular UJTs are very
>>rare these days so initially I looked at the PUT which is basically a
>>thyristor with a negative (anode end) gate, my first thought is that an SCS
>>(silicon controlled switch) - a 4-layer thyristor device with both gates
>>available would be relatively easy for a TV engineer to obtain, and failing
>>that, one can be constructed easily with a complementary pair of small
>>signal transistors.
>>
>>However as I looked at the circuit - and the complementary asymmetry of the
>>4-layer device, I realised that it was possible to turn the circuit upside
>>down and use a small TO-92 thyristor to the same effect. Thyristors of this
>>type are quite common in TV & monitor PSUs - not least as safety trip
>>devices, so almost by accident the project became a dual purpose component
>>tester.
>>
>>Don't be too hasty to count out the tunnel diode - according the manual, the
>>Tek465 scope contains a couple of them.
>>
>>
>
> But that was one of the exceptions. IN the hobby realm, they were a novelty
> and nothing that was published could not be done with some other device.
>
> In that scope, it's either in the trigger system, or it's generating a pulse
> (I forget, though I know at some point I did read what the tunnel diode
> was doing).
>
> ANd yes, if you needed to replace that tunnel diode, you'd need a tunnel
> diode. But, even for that, there seems to be a fair consensus that getting
> a tunnel diode at this point would require effort at the very least.
>
Effort plus a well padded bank account. Unless you can find a similar
scope with a shot CRT on EBay for parts. But then shipping will eat your
money.
--
Regards, Joerg
http://www.analogconsultants.com
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Author: JoergDate: 18:36 17-03-07
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ian field wrote:
> "Joerg" <notthisjoergsch@removethispacbell.net> wrote in message
> news:7dWKh.5529$tv6.5086@newssvr19.news.prodigy.net...
>
>
>
>>As a kid I always laughed when I saw yet another circuit proposal with a
>>tunnel diode or a UJT. None of the stores had any, not even the big ones
>>in large cities. Looked like someone just had to publish it to show off. I
>>built my oscillators with scavenged AF139/239. Or sometimes tubes.
>
>
> A few years ago I had a project published in Television Magazine which was
> loosely based on a Programmable Unijunction Transistor (PUT).
>
> The project met the need for testing opto-couplers that did not offer an
> electrical connection to the photo-transistor's base terminal making the
> usual "diode" tests impossible, this required a cheap simple and minimum
> parts count pulse generator to drive the LED, granted regular UJTs are very
> rare these days so initially I looked at the PUT which is basically a
> thyristor with a negative (anode end) gate, my first thought is that an SCS
> (silicon controlled switch) - a 4-layer thyristor device with both gates
> available would be relatively easy for a TV engineer to obtain, and failing
> that, one can be constructed easily with a complementary pair of small
> signal transistors.
>
> However as I looked at the circuit - and the complementary asymmetry of the
> 4-layer device, I realised that it was possible to turn the circuit upside
> down and use a small TO-92 thyristor to the same effect. Thyristors of this
> type are quite common in TV & monitor PSUs - not least as safety trip
> devices, so almost by accident the project became a dual purpose component
> tester.
I needed something similar at a client. At my lab I have one, a plain
old pencil shaped signal injector. But new TSA rules consider that a
dangerous items. So.... I made sure the client had some CMOS logic at
hand. Took a single Schmitt inverter (but a 74HC14 would also have
sufficed), one resistor, one cap and bingo, I had a new pulser.
>
> Don't be too hasty to count out the tunnel diode - according the manual, the
> Tek465 scope contains a couple of them.
>
In their haydays those big scopes fell into the category "money is not
an objective" :-)
--
Regards, Joerg
http://www.analogconsultants.com
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Author: ian fieldDate: 18:43 17-03-07
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"Joerg" <notthisjoergsch@removethispacbell.net> wrote in message
news:KYZKh.8194$yW.6784@newssvr11.news.prodigy.net...
> ian field wrote:
>
>> "Joerg" <notthisjoergsch@removethispacbell.net> wrote in
message
>> news:bnWKh.13743$FG1.5206@newssvr27.news.prodigy.net...
>>
>>>ian field wrote:
>>>
>>>
>>>>"Michael Black" <et472@FreeNet.Carleton.CA> wrote in
message
>>>>news:etgtii$rih$1@theodyn.ncf.ca...
>>>>
>>>>
>>>>
>>>>>I thought people talked about power germaniums still being made and
>>>>>used.
>>>>>The talk would have been in one of the sci.electronics.* newsgroups
>>>>>sometime
>>>>>in the past decade, but that's the best I can provide as a pointer.
>>>>>
>>>>> Michael
>>>>>
>>>>
>>>>
>>>>Way back in the early days when silicon devices were new, I often
>>>>wondered - if silicon is so good, why is germanium still used in the
>>>>power stages of radios that have silicon RF/IF stages?
>>>
>>>Old rule: As long as Ge was only one cent less than Si, they'd use Ge.
>>>Maybe the fact that many cars were still equipped with 6V systems also
>>>favored Ge.
>>
>>
>> The 12V auto-electrics were well and truly established in the period I
>> remember, and don't forget the first ever transistor radio used a 22-1/2V
>> (tube) hearing aid battery - presumably the PP3 hadn't been invented yet.
>
> Then you must be young. My first car was built in 1969 (I got it around
> 1980). A Citroen 2CV, 6V electrics all through out. Number of electronic
> components in that car before installing the radio with its Ge
> transistors: Zilch. Not even a diode.
Call that a car - its French FFS!
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Author: ian fieldDate: 18:47 17-03-07
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"Joerg" <notthisjoergsch@removethispacbell.net> wrote in message
news:S3_Kh.8197$yW.5299@newssvr11.news.prodigy.net...
> ian field wrote:
>
>> "Joerg" <notthisjoergsch@removethispacbell.net> wrote in
message
>> news:7dWKh.5529$tv6.5086@newssvr19.news.prodigy.net...
>>
>>
>>
>>>As a kid I always laughed when I saw yet another circuit proposal with a
>>>tunnel diode or a UJT. None of the stores had any, not even the big ones
>>>in large cities. Looked like someone just had to publish it to show off.
>>>I built my oscillators with scavenged AF139/239. Or sometimes tubes.
>>
>>
>> A few years ago I had a project published in Television Magazine which
>> was loosely based on a Programmable Unijunction Transistor (PUT).
>>
>> The project met the need for testing opto-couplers that did not offer an
>> electrical connection to the photo-transistor's base terminal making the
>> usual "diode" tests impossible, this required a cheap simple and
minimum
>> parts count pulse generator to drive the LED, granted regular UJTs are
>> very rare these days so initially I looked at the PUT which is basically
>> a thyristor with a negative (anode end) gate, my first thought is that an
>> SCS (silicon controlled switch) - a 4-layer thyristor device with both
>> gates available would be relatively easy for a TV engineer to obtain, and
>> failing that, one can be constructed easily with a complementary pair of
>> small signal transistors.
>>
>> However as I looked at the circuit - and the complementary asymmetry of
>> the 4-layer device, I realised that it was possible to turn the circuit
>> upside down and use a small TO-92 thyristor to the same effect.
>> Thyristors of this type are quite common in TV & monitor PSUs - not least
>> as safety trip devices, so almost by accident the project became a dual
>> purpose component tester.
>
>
> I needed something similar at a client. At my lab I have one, a plain old
> pencil shaped signal injector. But new TSA rules consider that a dangerous
> items. So.... I made sure the client had some CMOS logic at hand. Took a
> single Schmitt inverter (but a 74HC14 would also have sufficed), one
> resistor, one cap and bingo, I had a new pulser.
>
>>
>> Don't be too hasty to count out the tunnel diode - according the manual,
>> the Tek465 scope contains a couple of them.
>
> In their haydays those big scopes fell into the category "money is not an
> objective" :-)
Maybe I got the number wrong - its not one of those big "double decker bus"
scopes you wheel about on a trolley.
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Author: JoergDate: 19:22 17-03-07
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ian field wrote:
> "Joerg" <notthisjoergsch@removethispacbell.net> wrote in message
> news:KYZKh.8194$yW.6784@newssvr11.news.prodigy.net...
>
>>ian field wrote:
>>
>>
>>>"Joerg" <notthisjoergsch@removethispacbell.net> wrote in
message
>>>news:bnWKh.13743$FG1.5206@newssvr27.news.prodigy.net...
>>>
>>>
>>>>ian field wrote:
>>>>
>>>>
>>>>
>>>>>"Michael Black" <et472@FreeNet.Carleton.CA> wrote in
message
>>>>>news:etgtii$rih$1@theodyn.ncf.ca...
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>>I thought people talked about power germaniums still being made
and
>>>>>>used.
>>>>>>The talk would have been in one of the sci.electronics.*
newsgroups
>>>>>>sometime
>>>>>>in the past decade, but that's the best I can provide as a
pointer.
>>>>>>
>>>>>>Michael
>>>>>>
>>>>>
>>>>>
>>>>>Way back in the early days when silicon devices were new, I often
>>>>>wondered - if silicon is so good, why is germanium still used in the
>>>>>power stages of radios that have silicon RF/IF stages?
>>>>
>>>>Old rule: As long as Ge was only one cent less than Si, they'd use Ge.
>>>>Maybe the fact that many cars were still equipped with 6V systems also
>>>>favored Ge.
>>>
>>>
>>>The 12V auto-electrics were well and truly established in the period I
>>>remember, and don't forget the first ever transistor radio used a 22-1/2V
>>>(tube) hearing aid battery - presumably the PP3 hadn't been invented yet.
>>
>>Then you must be young. My first car was built in 1969 (I got it around
>>1980). A Citroen 2CV, 6V electrics all through out. Number of electronic
>>components in that car before installing the radio with its Ge
>>transistors: Zilch. Not even a diode.
>
>
> Call that a car - its French FFS!
>
Don't know what FFS means but that was a great car. 16 horses, about
50mpg on regular unleaded and transported a huge fridge that a guy
couldn't get into his VW bus. He was pretty embarrassed.
Heck, I could even adjust the shock absorber strengths on it with
getting dirty.
--
Regards, Joerg
http://www.analogconsultants.com
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Author: Michael A. TerrellDate: 22:15 17-03-07
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Joerg wrote:
>
> ian field wrote:
>
> > "Joerg" <notthisjoergsch@removethispacbell.net> wrote in
message
> > news:KYZKh.8194$yW.6784@newssvr11.news.prodigy.net...
> >
> >>ian field wrote:
> >>
> >>
> >>>"Joerg" <notthisjoergsch@removethispacbell.net> wrote
in message
> >>>news:bnWKh.13743$FG1.5206@newssvr27.news.prodigy.net...
> >>>
> >>>
> >>>>ian field wrote:
> >>>>
> >>>>
> >>>>
> >>>>>"Michael Black" <et472@FreeNet.Carleton.CA>
wrote in message
> >>>>>news:etgtii$rih$1@theodyn.ncf.ca...
> >>>>>
> >>>>>
> >>>>>
> >>>>>
> >>>>>>I thought people talked about power germaniums still being
made and
> >>>>>>used.
> >>>>>>The talk would have been in one of the sci.electronics.*
newsgroups
> >>>>>>sometime
> >>>>>>in the past decade, but that's the best I can provide as a
pointer.
> >>>>>>
> >>>>>>Michael
> >>>>>>
> >>>>>
> >>>>>
> >>>>>Way back in the early days when silicon devices were new, I
often
> >>>>>wondered - if silicon is so good, why is germanium still used
in the
> >>>>>power stages of radios that have silicon RF/IF stages?
> >>>>
> >>>>Old rule: As long as Ge was only one cent less than Si, they'd use
Ge.
> >>>>Maybe the fact that many cars were still equipped with 6V systems
also
> >>>>favored Ge.
> >>>
> >>>
> >>>The 12V auto-electrics were well and truly established in the period I
> >>>remember, and don't forget the first ever transistor radio used a
22-1/2V
> >>>(tube) hearing aid battery - presumably the PP3 hadn't been invented
yet.
> >>
> >>Then you must be young. My first car was built in 1969 (I got it around
> >>1980). A Citroen 2CV, 6V electrics all through out. Number of electronic
> >>components in that car before installing the radio with its Ge
> >>transistors: Zilch. Not even a diode.
> >
> >
> > Call that a car - its French FFS!
> >
>
> Don't know what FFS means but that was a great car. 16 horses, about
> 50mpg on regular unleaded and transported a huge fridge that a guy
> couldn't get into his VW bus. He was pretty embarrassed.
16 HP? My dad's lawn mower is 18 HP.
--
Service to my country? Been there, Done that, and I've got my DD214 to
prove it.
Member of DAV #85.
Michael A. Terrell
Central Florida
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Author: Michael A. TerrellDate: 22:18 17-03-07
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Joerg wrote:
>
> Then you must be young. My first car was built in 1969 (I got it around
> 1980). A Citroen 2CV, 6V electrics all through out. Number of electronic
> components in that car before installing the radio with its Ge
> transistors: Zilch. Not even a diode.
US cars were 12 volts a lot earlier than that. My '61 Ford Galaxy was
12 VDC. I could dig through my collection of Sams Photofact car radio
manuals to find the exact dates, but 12 VDC was in wide use when car
radios were still using vacuum tubes in the US.
--
Service to my country? Been there, Done that, and I've got my DD214 to
prove it.
Member of DAV #85.
Michael A. Terrell
Central Florida
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Author: Michael A. TerrellDate: 22:21 17-03-07
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ian field wrote:
>
> In the period I'm thinking of transformer coupled O/P stages still hadn't
> been completely outdated by complementary pairs so they could have chosen
> whichever polarity suited best - it just seemed to take a while to develop
> silicon transistors that could supersede germanium in power stages.
US car radio audio output transistors went from PNP Germanium to NPN
Silicon in one step. The first I saw was the Bendix with the early
TO-220 where they bent the leads right at the body to fit the spacing on
a TO-3 transistor and had an almost 100% field failure rate within a
year.
--
Service to my country? Been there, Done that, and I've got my DD214 to
prove it.
Member of DAV #85.
Michael A. Terrell
Central Florida
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