[Lowfer] Jackson Harbor kit

[Stewart Nelson]

Hi Bill, Mike, and all,

Here is an excerpt of post from March.

> These units are KTXO-18 DIP modules by Kyocera, intended for use in
> cellular handsets.  Comments below are based on the manufacturer's
> spec, as well as my tests on one part from the lot.
> 
> Nominal frequency is 12.8 MHz.  Output is AC coupled, but can drive
> HCMOS or LSTTL by just connecting two resistors to the output.
> 
> There is a manual trimmer but no electrical frequency control.
> Kyocera spec is +/- 3 ppm minimum adjustment, but the actual range is
> about +/- 20 ppm, in the usual 180 degrees, so it takes a while to set
> it better than 0.1 ppm.  Before adjustment, the test unit measured
> 12.8000121 MHz at 20 deg. C.
> 
> Frequency versus voltage is pretty good.  Spec is +/- 0.3 ppm over a
> +/- 5% change in supply.  Actual shift was only 1 Hz for 200 mV
> change.  I would guess that most systems would exhibit a supply
> voltage change of less than 10 mV during a half hour transmission;
> this would be less than 1 mHz at LF.
> 
> Temperature stability, however, is not so great.  Claimed is +/- 3 ppm
> from -20 to +60 C.  But the curve has at least two inflections, and
> the slope is about 0.05 ppm per degree at say, 15 C.  If you consider
> decent lowfer stability to be 0.01 Hz over a half hour transmission,
> then the temperature would need to change no more than 2 C per hour.
> Most indoor living spaces conform, but many shacks are in locations
> that don't.
> 
> Long term drift spec is 1 ppm per year.  The test unit has been
> connected to a counter for the past month.  During the first week,
> frequency fell about 0.1 ppm, and then started to rise.  It's
> presently increasing about 0.01 ppm per week.
> 
> I found an interesting PIC-based timer that uses this oscillator at
> http://www.picfun.com/equipj39.html .  The above page has a spec,
> picture, and schematic showing how to drive a PIC.  If you have Win 2k
> or XP, there should be no trouble viewing the page, otherwise you may
> need Japanese fonts or language pack.
> 
> I was unable to find the official spec for this part on the web.  It
> is obsolete, since current handsets use surface mount parts.  However,
> I believe that the KT18 series is electrically almost identical.  At
> http://global.kyocera.com/frame/product/electro/ec/english/tmn/index.html
> you can download a TCXO catalog in English.

73,

Stewart KK7KA

----- Original Message ----- 
From: "Bill Ashlock" <ashlockw@hotmail.com>
To: <lowfer@mailman.qth.net>
Sent: Monday, November 03, 2003 3:19 AM
Subject: RE: [Lowfer] Jackson Harbor kit


> >I dug out the oscillator and it is a 12.8mc 1ppm device. Stewart wrote on
> >the paper that it measured 12.799985mc.
> 
> Mike do you know if that 1ppm is the stability, tempco (like 1ppm/degC), 
> initial accuracey, or something else?
> 
> Bill A