1N34A Germanium Diode finally found!!

[Tauno Voipio]

Point contact diodes are cheating;-)

A *real* crystal radio uses a piece of carborundum and a razor blade...

The classical one was a piece of galenite (lead sulfide PbS) and a
catwhisker, to create the first Schottky diode.

 

[Phil Hobbs]

Does anyone actually use just a diode for AM detection anymore?

...Jim Thompson

Diodes aren't so bad if you have reasonably quick AGC, and they avoid
some of the misbehaviour you can get with things like active peak
detectors, e.g. subharmonics and limit cycles. Plus they go a lot
faster than most ICs, e.g. 18 GHz back diode detectors.

(I made some at 200 THz a few years back, but their nonlinearity was
only a few percent. Diodes like that can produce >200 GHz at their
output terminals. I'm hoping to have a chance to revisit that later
this year, but we'll see in a week or two--it's hard to get signatures
during the summer.)

Cheers

Phil Hobbs


--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC
Optics, Electro-optics, Photonics, Analog Electronics

160 North State Road #203
Briarcliff Manor NY 10510

hobbs at electrooptical dot net
http://electrooptical.net

 

[Phil Hobbs]

I recall Jameco, well "James Electronics" as Digikey's competitor. Been
using both of them for at least 35 years. My first job out of college
was right across the street from James Electronics in San Carlos. Now I
do will call if I need something fast.

There were some other surplus companies that were Polypak's competition.
A company in Florida called Knapp Electronics that printed their catalog
on newsprint.

Yes, I think you're right--it was Digikey vs. Jameco and Poly Paks vs.
the TV repair shop's dumpster.

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC
Optics, Electro-optics, Photonics, Analog Electronics

160 North State Road #203
Briarcliff Manor NY 10510

hobbs at electrooptical dot net
http://electrooptical.net

 

[Phil Hobbs]

Electronics surplus was a blast back then. There was a Cortland
Electronics that advertized in the ad section at the back of many
electronic hobby magazines and had a short catalog of oddball stuff?
I remember they got surplus stock of big old Burroughs Nixie tubes
and circuit cards full of huge naked reed switches (originally
intended for telephone switching?) Each reed was like 2 1/2 inches
long and the sound they made when closed or opened was almost like a
musical tuning fork.

My Dad taught me how to do high quality soldering when I was 9 or so.
I remember mounting an old tube TV power transformer in a box to
power an elementary school science fair project where I recreated
Edison's light bulb experiments by winding various types of iron wire
around a large sewing needle to make tiny coils and knowing that
vacuum and gas apparatus were out of reach for me at the time. The
large amperage 6.3V tube filament power would make the filaments glow
and then flare and burn open quite nicely. The higher voltage taps
were stubbed and insulated for safety. It was a nice science fair
project actually, kids liked seeing the filaments glow briefly and
then burn open. Good for elementary school.

At 12 I was building simple audio oscillators that used two
multivibrator circuits so they warbled. My favorite used 2 PNP and 2
NPN and by changing the various timing values the noise could be
varied wildly. My Dad wanted a loud noisemaker for the business
garage so I hung a power transistor and a big scavanged speaker at
the end and the warble would cut through a lot of engine noise. I
think I built that when I was like 13 and that loud thing kept
running for a decade at least. After a few years it surprised
somebody a bit too much so he put a pot or resistor in series with
the speaker to drop the volume and it kept running for many years.

By the time I was 18 I was building projects and buying parts from
James Electronics (later Jameco) and Mouser. When I got into TTL I
actually missed drawing traces and pads by hand using Sharpie markers
as etch resist and etching with a bottle of Radio Shack Ferric
Chloride. I could do a one off pretty fast. I'd go over the traces a
second time with sharpie intil the sharpie ink was fairly dark to
guarantee good resist. When I was in college, a few times I would
wake up in the middle of the night with a TTL circuit idea I just had
to commit to paper right away. At least two of them were TTL and did
get built.

The local electronics surplus retailers in Minneapolis had quite a
heyday in the late 1970's as well. Some hobbyist printed up and
handed out a map to the best dozen or so at one point. There was lots
of really good mil grade stuff surplused off cheap.

There's a whole lot of generally pretty good Soviet stuff on eBay these
days. I got a career's worth of 15 nF feedthrough caps, small ceramic
trimmers, small panel pots, and high-ohm resistors.

And the test equipment bonanza keeps on rolling. There are a lot of
dealers now, but even so, top quality boat anchors are going for a very
few cents on the dollar.

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC
Optics, Electro-optics, Photonics, Analog Electronics

160 North State Road #203
Briarcliff Manor NY 10510

hobbs at electrooptical dot net
http://electrooptical.net

 

[Spehro Pefhany]

I recall Jameco, well "James Electronics" as Digikey's competitor. Been
using both of them for at least 35 years. My first job out of college
was right across the street from James Electronics in San Carlos. Now I
do will call if I need something fast.

There were some other surplus companies that were Polypak's competition.
A company in Florida called Knapp Electronics that printed their catalog
on newsprint.

There a company with all kinds of cool stuff called Meshna?? or
something like that.

 

[Joerg]

People still make Ge back diodes, as rf detectors. They are, I think,
the only planar "ic" type fabrication done in germanium, except
photodiodes maybe.

In Europe we had mesa and planar Ge RF transistors. For example, this
one was a hot commodity among the "discarded TV set pilfering" crowd
because you could often find them hidden as the only transistors in tube
sets:

http://html.alldatasheet.com/html-pdf/44095/SIEMENS/AF239/244/1/AF239.html

[...]

 

[Joerg]

Does anyone actually use just a diode for AM detection anymore?

<raises hand>

 

[SMS]

On 8/29/2013 6:43 AM, Phil Hobbs wrote:

Yes, I think you're right--it was Digikey vs. Jameco and Poly Paks vs.
the TV repair shop's dumpster.

Poly Paks ad:
<http://www.flickr.com/photos/oskay/4455981283/sizes/l/in/photostream/>

 

[Joerg]

On 08/28/13 17:53, Jim Thompson wrote:

In the mid to late '80's I used 1N270's by the bucket load to clamp
LM324 and LM329 inputs, to avoid substrate diode injection and phase
inversion.

...Jim Thompson
Anyone remember the GE "back" diodes ?. Same can as their tunnel diodes,
but, iirc, very low forward voltage...

Chris
People still make Ge back diodes, as rf detectors. They are, I think,
the only planar "ic" type fabrication done in germanium, except
photodiodes maybe.

In Europe we had mesa and planar Ge RF transistors. For example, this
one was a hot commodity among the "discarded TV set pilfering" crowd
because you could often find them hidden as the only transistors in tube
sets:

http://html.alldatasheet.com/html-pdf/44095/SIEMENS/AF239/244/1/AF239.html

[...]

There were big TO3 and stud Ge power transistors, and I'm guessing that they
were a planar structure. If anybody has one, maybe they could decap it and take
pictures.

Germanium Power Devices was, I think, the last maker of Ge diodes and
transistors. They are now "GPD" and make photodiodes.

I think someone still makes Ge tunnel diodes.

These guys seem to still build Ge-diodes:

http://wxecl.en.china.cn/

But they state that they get the materials from overseas, so probably
fabless.

 

[Tim Williams]

WWII radars used silicon, germanium, and even gaas point-contact diodes.
One of
the RadLab books casually mentions that "a semiconductor triode should
be
possible."

Indeed. I recall reading an article about researchers trying that (a
triode) since about the turn of the century. Copper oxide doesn't even
make good rectifiers, let alone transistors, but the idea was there.

I forget when the FET was invented, but it predated the BJT theoretically
by some time; only after substantial process refinements were they finally
able to minimize surface states and make the things.

It's also cool that vacuum tubes work on the same theoretical principles:
charge transfer between dissimilar media, Fermi potentials, thermal
energy, band gaps; all the same, except semiconductors work on bulk
diffusion and charges spanning the band gap, while vacuum tubes work on
ballistic transport and electrons above the vacuum potential (no holes).

One whole volume of the RadLab books is "Crystal Rectifiers." They knew
a lot
about semiconductor physics in 1940.

https://dl.dropboxusercontent.com/u/53724080/Parts/RadLabDiodes.JPG

Notice that, unlike a semiconductor diode [in the absence of light], the
6AL5 is an overunity diode (notice the zero intercept).

Yeah, making an "in the absence of light" comparison is silly because the
6AL5 makes a little light, too. (I've seen at least one eBay auction
advertising the worthless buggers for Christmas tree lights and other
assorted uses...) The actual thermodynamics are, of course, a very
inefficient heat pump.

Tim

 

[Spehro Pefhany]

John Larkin wrote:

On 08/28/13 17:53, Jim Thompson wrote:

In the mid to late '80's I used 1N270's by the bucket load to clamp
LM324 and LM329 inputs, to avoid substrate diode injection and phase
inversion.

...Jim Thompson
Anyone remember the GE "back" diodes ?. Same can as their tunnel diodes,
but, iirc, very low forward voltage...

Chris

People still make Ge back diodes, as rf detectors. They are, I think,
the only planar "ic" type fabrication done in germanium, except
photodiodes maybe.


In Europe we had mesa and planar Ge RF transistors. For example, this
one was a hot commodity among the "discarded TV set pilfering" crowd
because you could often find them hidden as the only transistors in tube
sets:

http://html.alldatasheet.com/html-pdf/44095/SIEMENS/AF239/244/1/AF239.html

[...]

There were big TO3 and stud Ge power transistors, and I'm guessing that they
were a planar structure. If anybody has one, maybe they could decap it and take
pictures.

Germanium Power Devices was, I think, the last maker of Ge diodes and
transistors. They are now "GPD" and make photodiodes.

I think someone still makes Ge tunnel diodes.

GPD is a pretty good outfit. They're my preferred IR photodiode
supplier--their stuff is good, it costs 1/3 to 1/2 of what Hamamatsu
wants for the same thing, and you can get the designer on the phone.

Cheers

Phil Hobbs

R.I.P. "Oliver Germanium".

http://www.legacy.com/obituaries/bostonglobe/obituary.aspx?n=oliver-o-ward&pid=153956149#fbLoggedOut

 

[Phil Hobbs]

John Larkin wrote:

On 08/28/13 17:53, Jim Thompson wrote:

In the mid to late '80's I used 1N270's by the bucket load to clamp
LM324 and LM329 inputs, to avoid substrate diode injection and phase
inversion.

...Jim Thompson
Anyone remember the GE "back" diodes ?. Same can as their tunnel diodes,
but, iirc, very low forward voltage...

Chris

People still make Ge back diodes, as rf detectors. They are, I think,
the only planar "ic" type fabrication done in germanium, except
photodiodes maybe.


In Europe we had mesa and planar Ge RF transistors. For example, this
one was a hot commodity among the "discarded TV set pilfering" crowd
because you could often find them hidden as the only transistors in tube
sets:

http://html.alldatasheet.com/html-pdf/44095/SIEMENS/AF239/244/1/AF239.html

[...]

There were big TO3 and stud Ge power transistors, and I'm guessing that they
were a planar structure. If anybody has one, maybe they could decap it and take
pictures.

Germanium Power Devices was, I think, the last maker of Ge diodes and
transistors. They are now "GPD" and make photodiodes.

I think someone still makes Ge tunnel diodes.

GPD is a pretty good outfit. They're my preferred IR photodiode
supplier--their stuff is good, it costs 1/3 to 1/2 of what Hamamatsu
wants for the same thing, and you can get the designer on the phone.

Cheers

Phil Hobbs

Is "Oliver Germanium" still in charge?

I think his son runs it now, but he's still around. IIRC Fred Molinari
still runs Data Translation, too.

Cheers

Phil Hobbs


--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC
Optics, Electro-optics, Photonics, Analog Electronics

160 North State Road #203
Briarcliff Manor NY 10510 USA
+1 845 480 2058

hobbs at electrooptical dot net
http://electrooptical.net

 

[Phil Hobbs]

On 08/29/2013 11:40 AM, John Larkin wrote:
John Larkin wrote:

On 08/28/13 17:53, Jim Thompson wrote:

In the mid to late '80's I used 1N270's by the bucket load to clamp
LM324 and LM329 inputs, to avoid substrate diode injection and
phase
inversion.

...Jim Thompson
Anyone remember the GE "back" diodes ?. Same can as their tunnel
diodes,
but, iirc, very low forward voltage...

Chris

People still make Ge back diodes, as rf detectors. They are, I think,
the only planar "ic" type fabrication done in germanium, except
photodiodes maybe.


In Europe we had mesa and planar Ge RF transistors. For example, this
one was a hot commodity among the "discarded TV set pilfering" crowd
because you could often find them hidden as the only transistors in
tube
sets:

http://html.alldatasheet.com/html-pdf/44095/SIEMENS/AF239/244/1/AF239.html


[...]

There were big TO3 and stud Ge power transistors, and I'm guessing
that they
were a planar structure. If anybody has one, maybe they could decap
it and take
pictures.

Germanium Power Devices was, I think, the last maker of Ge diodes and
transistors. They are now "GPD" and make photodiodes.

I think someone still makes Ge tunnel diodes.


GPD is a pretty good outfit. They're my preferred IR photodiode
supplier--their stuff is good, it costs 1/3 to 1/2 of what Hamamatsu
wants for the same thing, and you can get the designer on the phone.

Cheers

Phil Hobbs

Is "Oliver Germanium" still in charge?

I think his son runs it now, but he's still around. IIRC Fred Molinari
still runs Data Translation, too.

Looks like I was out of date--I asked my GPD friends about Oliver a few
years ago, and he was still extant.

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC
Optics, Electro-optics, Photonics, Analog Electronics

160 North State Road #203
Briarcliff Manor NY 10510 USA
+1 845 480 2058

hobbs at electrooptical dot net
http://electrooptical.net

 

[Greegor]

GPD is a pretty good outfit. They're my preferred

IR photodiode supplier--their stuff is good, it
costs 1/3 to 1/2 of what Hamamatsu wants for the
same thing, and you can get the designer on the
phone. Cheers Phil Hobbs

This one?

Gpd Optoelectronics Corp
7 Manor Parkway
Salem, NH 03079-2842

(603) 894-6865