Tunnel Diode Oscillator

[Andre Kesteloot]

Joe,

Yes, unadulterated fun :-
73
André N4ICK

+++++++++++++++++++++++++++++++++++++++++

On 3/22/2014 1:04 AM, Joseph Bento wrote:
> 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>
>>>
>>>
>>> <mime-attachment.jpg>
>>>
>>> <mime-attachment.jpg>
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>
>


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