Who remembers the tunnel diode?

[GK]

http://n4trb.com/AmateurRadio/SemiconductorHistory/GE_Tunnel_Diodes.pdf


The revolutionary new semiconductor device that, well, wasn’t.
Does anyone know of a contemporary tunnel diode? Just curious and I wouldn’t mind experimenting with a few; but that might have to be with some ancient “NOS” acquired through Ebay.

[FenderBender]

Every time I walk into my shop I have to go through a series of spiritual rituals to make sure one of these doesn't die in my scope. Unobtanium!

[GK]

Ha! According to that GE article they are nuclear bomb proof! Is that a sampling oscilloscope?

[GeoffS]

I like the reference in the document to 'kilomegacycle' 

[RCMR]

That's spooky -- I was just scanning the web for tunnel diodes the other day.

I've got a 10GHz doppler radar module here that uses a tunnel diode and was wondering what to do if I blow it.

Of course we've got better ways of creating microwave frequencies these days so for that application, the tunnel diode is redundant.

[ee851]

I never heard of it.    So I guess I wasn't an adult way back then.   Whenever that was.       There were things in glass vacuum tubes that were like diodes and amplifiers way back before my time.   I never learned about them either.     They're obsolete.   But some hams still use them.     I am a ham.   So I would use one if I had one that stil worked.

[Pentium100]

The only time I saw a tunnel diode from up close was a few years ago in a lab - the assignment was to measure (and later plot) the IV curve. If I had one I would not know what to do with it - after all, it seems to me that it would be easier to build a transmitter with vacuum tubes than the tunnel diode (since IIRC all tunnel diodes are low power, so I would still have to use tubes to amplify the power). However, since I am incapable ow inding a coil (so it has specified parameters), I won't be building any transmitters any time soon.

[RCMR]

Back in the day, tunnel diodes were the easiest way to create a low-power microwave source.

Many of the low-power X-band doppler radars (as used in home-security systems and as automatic door-openers back in the 1970s/80s) were tunnel diode based.

Just throw a tunnel diode in a resonant cavity, bias it appropriately and bingo -- instant microwave-source.

I think the unit I have is about 5-8mW at 10.5GHz.

[Lukas]

Just throw a tunnel diode in a resonant cavity, bias it appropriately and bingo -- instant microwave-source.

Gunn diodes do the job as well and are much less unobtainium.

[vk6zgo]

Tunnel diodes were used extensively at one time,but their performance was overtaken by more conventional devices.

The only thing I remember using which used them was a TU-5 Pulser,which,when driven by the reasonably slow calibration signal,produced a fast rise time pulse allowing you to test an oscilloscope's transient response.

[G7PSK]

In the late 60's there was a record held by a radio amateur for long distance transmission with low power, from Newzealand to America with less than a quarter watt using a tunnel diode transmitter. 

[PA0PBZ]

I remember buying one as a teenager. It looked like a very interesting device to build a small transmitter.
Unfortunately it was expensive (for me) and I never got it working, probably killed it 
That was my first and last tunnel diode experiment. I wonder if it is still in one of the weird stuff drawers...

[vis1-0n]

I remember buying one as a teenager. It looked like a very interesting device to build a small transmitter.

I was around 13-15 years old in the early 90's and I remember finding the schematics to FM transmitters in one of those 1001 "Electronics circuits"-type books at the public reference library. It had no exotic (GE,HF) transistors, just resistors and capacitors to go with the TD. It seemed so super simple that I walked around the shops looking for one in vain.

[saturation]

I still use it on my venerable Tek 284 pulse generator reference.  70ps or less and 1 GHz reference signals made in the 1960s.



There is still quite a bunch of overstock easily found on eBay.  IIRC Russia still makes them new.

http://www.ebay.com/sch/?_nkw=tunnel%20diodes&clk_rvr_id=393658061107

[G7PSK]

Just came across this on the net after a Google search on tunnel diodes.

http://www.sparkbangbuzz.com/els/ntype-nr-el.htm

[KD0CAC John]

I had one of these , it was in a small / cheap GDO - Grid Dip Oscillator , from Heathkit .
I quickly moved on to several other GDOs that performed much better , but were much bigger .

http://www.radiomuseum.org/r/heath_tunnel_dipper_hm_10_a_hm1.html
 

[PA0PBZ]

I had one of these , it was in a small / cheap GDO - Grid Dip Oscillator , from Heathkit .

That would make it a TDO then? 

[GK]

driven by the reasonably slow calibration signal,produced a fast rise time pulse allowing you to test an oscilloscope's transient response.

Yes, that is what I would like to do. Looks like I have plenty NOS to choose from on ebay.