[time-nuts] "Vanguard Ultra precision Golden Oscillator"

[Bob Camp]

> On Aug 29, 2015, at 9:48 AM, Attila Kinali <attila at kinali.ch> wrote:
> 
> On Sun, 23 Aug 2015 19:29:29 -0700
> Hal Murray <hmurray at megapathdsl.net> wrote:
> 
> 
>> What's magic about a crystal as compared to an osc?  Is it really easier to 
>> get an odd-ball frequency in a crystal vs an osc?
> 
> As Bob already mentioned, there are more frequencies/types to pick from
> when going for single crystals. The reason for this is quite simple: volume.
> The volume in this case comes from people who need an oscillator with some
> spec. If they build the oscillator themselves, it's just pick a crystal,
> some feedback (transistor, logic gate, opamp,..) and measure whether the
> specs are met. Repeat until done. The crystal is only one part that helps
> meeting the specs, the feedback circuit, power supplies etc are the others.
> Because a crystal, in this case, is just a Lego part of a larger device,
> they become more versatile and as get a higher volume.
> 
> On the other hand, if manufacturer chooses to build a oscillator, the
> manufacturer will have to decide on what specs to meet. Of course the
> better the specs the more projects it will fit in. But it will also make
> the oscillator more expensive and thus a worse fit for cost sensitive
> products, that do not need the high specs. I.e. with a pre-build oscillator
> the engineer lost one tuning knob with which he can optimize the circuit
> for his application.
> 
> Things become interesting with "special" devices. E.g. SC Cut crystals
> are quite hard to come by. There are few manufacturers who sell them,
> while there are many manufacturers that sell oscillators with SC cut crystals.
> How market dynamics work in this case, i am not exactly sure.

A SC cut crystal is not something you can just drop on an MCU and get things 
running. They are of little use without an oven to go around them. In large volumes 
the price of a simple SC cut OCXO is surprisingly low. There is little incentive
for an OEM to go out and set up all the “stuff’ to use the SC crystals by themselves.

Bob


> 
> 
> 				Attila Kinali
> 
> -- 
> I must not become metastable. 
> Metastability is the mind-killer.
> Metastability is the little-death that brings total obliteration.
> I will face my metastability. 
> I will permit it to pass over me and through me. 
> And when it has gone past I will turn the inner eye to see its path. 
> Where the metastability has gone there will be nothing. Only I will remain.
> 
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