[time-nuts] Re: pulling some crystals

[glen english LIST]

thanks Bob and Rick for your fine input, Rick thanks for the treatment , 
I will follow your recipe and report back. Yes these days I have 
troubles with AVAILABLE SMT RF transistors, they all have Fts 4-10 GHz 
and I generally resort to common base with ballast R. 2N5179 I used to 
put a bead on the emitter lead as described in "ARRL Solid State Design 
" remember that ?

If I ran out of pull after 10 years  while  I can tell the radio just to 
go off freq a bit (digital fix in FPGA) , the issue then is the digital 
sample rate fixed to the oscillator  go off meaning the world runs fast 
or slow.

 From the manufacturer, Krystaly ,  on my batch of 3OT  98.304 crystals 
: I reproduce word for word here. These guys are very helpful.

"

All our crystals have undergo the process of preaging, also called 
"accelerated aging" (i.e. 3 days storage at +105 deg.C). This aging is 
equivalent to one year aging at normal temperature (according standard 
IEC 60122-1). The crystals produced for you had frequency shift after 
this preaging below 1.0 ppm, so it guaranties aging below 10 ppm after 
10 years. The aging curve shows deceleration (saturation) in time.
Information to pulling parameter:
Trimsensitivity at frequency 98.304 MHz, 3.rd  overtone is approx. 35 
ppm/pF.
Trimsensitivity at frequency 32.768 MHz, 1.st  overtone is approx. 400 
ppm/pF so ten times higher."

regards

On 8/12/2023 4:19 am, Richard Karlquist wrote:
>
> When I was working for Zeta Labs, circa 1978, I was in charge of a 
> huge order for 5th overtone VCXO's.  My boss told me to use the 
> "standard Zeta VCXO design".  It had various problems, and I quickly 
> decided to invent a new design that actually worked right, and quietly 
> put it into production without alerting my boss.  The new design was 
> wildly suc
>