Tunnel Diode Oscillator

[Joseph Bento]

Hi André,

I've been building for many, many years.  Tunnel diodes predate me, 
however, as they had already become somewhat rare by the 1970's when my 
electronics hobby interest began in earnest.

Over the past few years, I've started ordering many obscure electronics 
parts from Russia, as many of these components remained in manufacture 
right until the end of the cold war. Since I really enjoy "antique" 
electronics as my hobby, these parts will keep me busy for years to 
come.  It's nice to leave the surface mount stuff behind at work each day.

The tunnel diode seems to be one of those magical parts in its 
operation.  I need to stay awake long enough to read through the theory 
of how and why they work.  :-)

Joe, N6DGY

On 3/21/2014 8:56 PM, Andre Kesteloot wrote:
> Joe,
> Nothing like building something, and then seeing it working, to restore our pride and confidence :-)
> 73
> André N4ICK
>
> Sent from my iPhone
>
>
>
>> On Mar 21, 2014, at 22:13, Joseph Bento <joseph at kirtland.com> wrote:
>>
>> Hi Guys,
>>
>> This was already shared with some of you.  My first tunnel diode oscillator!
>>
>> It works... Oscillation is at about 20MHz.  Not exactly a good circuit for a solderless breadboard, but it at least exhibits the behavior I was seeking.  I may need to investigate a proper frequency counter at Hamvention.  Right now, using 1/x on the scope     gives a rough estimate.  My coil and cap are not the values on the schematic.
>>
>> I've already discovered that the power supply in a tunnel diode circuit is critical.  Since these Russian diodes I ordered are GaAs, that may affect the operating characteristics as well.  I don't know...  that's something I'll need to learn.  My source voltage to achieve oscillation is about 3v.  The schematic shows 1.5v.   I assume the old General Electric diodes as in the schematic are probably germanium.  I may need to seek out a couple samples.
>>
>> Now I'll have to move on to a nice QRP 40m transmitter using proper construction techniques.  :-)
>>
>> Perhaps Brian will consider the talk on tunnel diodes for the AMRAD picnic.
>>
>> Joe, N6DGY
>>
>> <TD.png>
>>
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