1 V oscillator.

I'm sitting on a heap of germanium transistors. From the time that
computers made of discrete germanium transistors were decommissioned.
Also 10 mm and 6 mm ferrite core.
Can I make on oscillator, that runs on 1V , preferably using
coils ? (Also trying to use LTSpice for the first time.)
I can measure inductance of coils thanks to the miracle component
testers from China.

Groetjes Albert
-- 
Don't praise the day before the evening. One swallow doesn't make spring.
You must not say "hey" before you have crossed the bridge. Don't sell the
hide of the bear until you shot it. Better one bird in the hand than ten in
the air. First gain is a cat spinning.            - the Wise from Antrim -

On a sunny day (Sat, 06 Jan 2024 14:31:49 +0100) it happened
albert@cherry.(none) (albert) wrote in
<nnd$30302dcf$1e37b7a5@bbcc4a9e0386ea66>:

>I'm sitting on a heap of germanium transistors. From the time that
>computers made of discrete germanium transistors were decommissioned.
>Also 10 mm and 6 mm ferrite core.
>Can I make on oscillator, that runs on 1V , preferably using
>coils ?

Yes, Ge transistors start conducting from 150 mV Vbe to maybe 300 mV, so much less than Si .7 V,
Any LC oscillator will work.
Tuned circuit LC in the collector, feedback 1 turn (correct phase) to the base?

In article <unbpba$35rk$1@solani.org>,
Jan Panteltje  <alien@comet.invalid> wrote:
>On a sunny day (Sat, 06 Jan 2024 14:31:49 +0100) it happened
>albert@cherry.(none) (albert) wrote in
><nnd$30302dcf$1e37b7a5@bbcc4a9e0386ea66>:
>
>>I'm sitting on a heap of germanium transistors. From the time that
>>computers made of discrete germanium transistors were decommissioned.
>>Also 10 mm and 6 mm ferrite core.
>>Can I make on oscillator, that runs on 1V , preferably using
>>coils ?
>
>Yes, Ge transistors start conducting from 150 mV Vbe to maybe 300 mV, so much less than Si .7 V,
>Any LC oscillator will work.
>Tuned circuit LC in the collector, feedback 1 turn (correct phase) to the base?

That sounds trivial. It is trivial. Not for me.
I need a schematic to build. Surely there must be some current into the base
for startup?

Groetjes Albert
-- 
Don't praise the day before the evening. One swallow doesn't make spring.
You must not say "hey" before you have crossed the bridge. Don't sell the
hide of the bear until you shot it. Better one bird in the hand than ten in
the air. First gain is a cat spinning.            - the Wise from Antrim -

On Sunday, January 7, 2024 at 2:07:40 AM UTC+11, none albert wrote:
> In article <unbpba$35rk$1...@solani.org>,
> Jan Panteltje <al...@comet.invalid> wrote: 
> >On a sunny day (Sat, 06 Jan 2024 14:31:49 +0100) it happened 
> >albert@cherry.(none) (albert) wrote in 
> ><nnd$30302dcf$1e37b7a5@bbcc4a9e0386ea66>: 
> > 
> >>I'm sitting on a heap of germanium transistors. From the time that 
> >>computers made of discrete germanium transistors were decommissioned. 
> >>Also 10 mm and 6 mm ferrite core. 
> >>Can I make on oscillator, that runs on 1V , preferably using 
> >>coils ? 
> > 
> >Yes, Ge transistors start conducting from 150 mV Vbe to maybe 300 mV, so much less than Si .7 V, 
> >Any LC oscillator will work. 
> >Tuned circuit LC in the collector, feedback 1 turn (correct phase) to the base?
> That sounds trivial. It is trivial. Not for me. 
> I need a schematic to build. Surely there must be some current into the base 
> for startup?

You could try the Baxandall class-D oscillator

http://sophia-elektronica.com/Baxandall1959JM.pdf

but pay attention to the footnote on page 752. You'll have to chose turns  ratios that give you enough base drive, but your should be able to put something together that runs from a 1V supply voltage if you are using germanium transistors.

Inverted transistors offer very low collector saturation voltage, so you might get away with less than a volt, if you swapped collector and emitters but you do need enough supply voltage to turn the bases on.

-- 
Bill Sloman, Sydney

On Sat, 06 Jan 2024 14:31:49 +0100, albert@cherry.(none) (albert)
wrote:

>I'm sitting on a heap of germanium transistors. From the time that
>computers made of discrete germanium transistors were decommissioned.
>Also 10 mm and 6 mm ferrite core.
>Can I make on oscillator, that runs on 1V , preferably using
>coils ? (Also trying to use LTSpice for the first time.)
>I can measure inductance of coils thanks to the miracle component
>testers from China.
>
>Groetjes Albert


1v should be easy with a ge transistor. 

People make oscillators that run off 10s of mV, but they usually use
jfets. A depletion phemt would be interesting.

Play with some ciruits in LTspice and post them here if you'd like us
to discuss them.

Is there an LT model of a germanium transistor?

Do you have an oscilloscope?

On Sat, 06 Jan 2024 14:50:17 GMT, Jan Panteltje <alien@comet.invalid>
wrote:

>On a sunny day (Sat, 06 Jan 2024 14:31:49 +0100) it happened
>albert@cherry.(none) (albert) wrote in
><nnd$30302dcf$1e37b7a5@bbcc4a9e0386ea66>:
>
>>I'm sitting on a heap of germanium transistors. From the time that
>>computers made of discrete germanium transistors were decommissioned.
>>Also 10 mm and 6 mm ferrite core.
>>Can I make on oscillator, that runs on 1V , preferably using
>>coils ?
>
>Yes, Ge transistors start conducting from 150 mV Vbe to maybe 300 mV, so much less than Si .7 V,
>Any LC oscillator will work.
>Tuned circuit LC in the collector, feedback 1 turn (correct phase) to the base?
>

Or something like this

https://ecstudiosystems.com/discover/textbooks/basic-electronics/oscillators/images/colpitts-oscillator.jpg

except it needs a power supply.

We were just discussing source-follower Colpitts oscillators yesterday
and concluded that we don't understand them.

On Sunday, January 7, 2024 at 3:05:04 AM UTC+11, John Larkin wrote:
> On Sat, 06 Jan 2024 14:31:49 +0100, albert@cherry.(none) (albert) 
> wrote:
> >I'm sitting on a heap of germanium transistors. From the time that 
> >computers made of discrete germanium transistors were decommissioned. 
> >Also 10 mm and 6 mm ferrite core. 
> >Can I make on oscillator, that runs on 1V , preferably using 
> >coils ? (Also trying to use LTSpice for the first time.) 
> >I can measure inductance of coils thanks to the miracle component 
> >testers from China. 
>
> 1v should be easy with a ge transistor. 
> 
> People make oscillators that run off 10s of mV, but they usually use 
> jfets. A depletion phemt would be interesting. 
> 
> Play with some ciruits in LTspice and post them here if you'd like us 
> to discuss them. 
> 
> Is there an LT model of a germanium transistor? 

https://grwhitehead.github.io/germaniumbjts/

Google is your friend.

<snipped silly question about an oscilloscope>

-- 
Bill Sloman, Sydney

albert <albert@cherry.(none)> wrote:

[...]

I realise this is completely off-topic but in your signature I see:
"First gain is a cat spinning. ".  This is an expression I have never
heard before, could you tell me what it means?


-- 
~ Liz Tuddenham ~
(Remove the ".invalid"s and add ".co.uk" to reply)
www.poppyrecords.co.uk

On Sat, 6 Jan 2024 16:45:37 +0000, liz@poppyrecords.invalid.invalid
(Liz Tuddenham) wrote:

>albert <albert@cherry.(none)> wrote:
>
>[...]
>
>I realise this is completely off-topic but in your signature I see:
>"First gain is a cat spinning. ".  This is an expression I have never
>heard before, could you tell me what it means?

I can add one factoid:  In Swedish (and perhaps all Nordic languages),
one literally says that a cat "spins" to say that it is purring.

Joe Gwinn

On 2024-01-06 11:03, John Larkin wrote:
> On Sat, 06 Jan 2024 14:31:49 +0100, albert@cherry.(none) (albert)
> wrote:
> 
>> I'm sitting on a heap of germanium transistors. From the time that
>> computers made of discrete germanium transistors were decommissioned.
>> Also 10 mm and 6 mm ferrite core.
>> Can I make on oscillator, that runs on 1V , preferably using
>> coils ? (Also trying to use LTSpice for the first time.)
>> I can measure inductance of coils thanks to the miracle component
>> testers from China.
>>
>> Groetjes Albert
> 
> 
> 1v should be easy with a ge transistor.
> 
> People make oscillators that run off 10s of mV, but they usually use
> jfets. A depletion phemt would be interesting.
> 
> Play with some ciruits in LTspice and post them here if you'd like us
> to discuss them.
> 
> Is there an LT model of a germanium transistor?
> 
> Do you have an oscilloscope?
> 

One issue with old germanium transistors is that they have horrible base 
leakage, enough to make the apparent beta negative in many cases.

Cheers

Phil Hobbs

-- 
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC / Hobbs ElectroOptics
Optics, Electro-optics, Photonics, Analog Electronics
Briarcliff Manor NY 10510

http://electrooptical.net
http://hobbs-eo.com