[time-nuts] uC ADC resolution (was: Poor man's oven)

[Will Kimber]

For under $20 you can get a OCXO with Si5351A multi output oscillator
chip from QRP-Labs.


http://www.qrp-labs.com/ocxokit.html


No idea just how good it is but this link gives insight into how it was
developed.  Designed for WSPR radio transmissions.  GPS discipline can
be added.


http://www.hanssummers.com/ocxosynth


Cheers,

Will


On 06/08/2017 06:10 AM, Chris Albertson wrote:

<snip>
> IT turrets out that you see MUCH more interesting designs when you lower
> the budget.  Anyone can make a high performance system even enough money.
> They waste half the cost on useless stuff and the product costs double what
> it should and is over complex but is works real, really well.   That's
> easy.  Harder and more interesting is "Can you make something just as good
> at 1/2 the price?"   Answer is usually Yes.  Then you say "what much do you
> loose if I set the price to 1/4?   The answer is surprisingly little if you
> get smart about sourcing parts.      Turns out about $180 is the minimum
> for pretty decent quality HiFi vacuum tube.
>
> An interesting graph would be Oven Specification vs. Price.  What is the
> minimum cost for keeping temperature to within 1.0 C, for 0.1C, 0.01 C?
>  Can you do 1.0C for under $5?   or 0.1C for under $10.    I bet yes.
>
> I did an exercise a while back to see what is the minimum price and
> complexity to build a GPSDO that was good enough only to drive the lab
> bench instruments I have.   I implements only 1/2 od Lars W's design and
> cut his lines of code by about 90%.  Turns outhe cost is the XO and about
> $10.   Compared to my Thunderbolt, performance was not nearly as good but
> the ratio of performance over parts cost might be better.
>
>
>