[time-nuts] NavSync CW12 and CW25

[Ed Palmer]

> Date: Fri, 8 Aug 2008 14:18:06 +1000
> From: "Pascal Nguyen" <vk2ihl at gmail.com>
> Subject: Re: [time-nuts] NavSync CW12 and CW25
> To: "Discussion of precise time and frequency measurement"
	<time-nuts at febo.com>
> Message-ID:
	<22ddffe10808072118i142373c5m2e26767deb2df3c at mail.gmail.com>
> Content-Type: text/plain; charset=UTF-8

> Hi Ed

> I build a 432.424MHz and 144.424MHz beacons for radio amateur application
> based on CW25-TIM modules ($150 ea july-07).
> I cannot provide any further details than the spec published by Navsync, due
> to lack of measurement facility, my set up is simply a Rb standard and two
> RT662 HF receivers driven with 5MHz source from Rb 10MHz/2) . Audio outputs
> are directed to PC soundcard and water falls are visually compared, an entry
> level for amateur like myself.
> I etched the PC board for 3V3 SM power supply, backup battery, RS 232
> converter (3v level) and 1PPS, NCO output, NMEA output, status LED
> indicators.
> My first board was populated with CW25 NAV, the only module available at
> that time, max freq 10MHz NCO.
> My second with CW25 TIM, max freq 30 MHz NCO

It looks like they've dropped the CW25-NAV.  It doesn't seem to be mentioned on their site.  They've also reduced the output frequency on the CW25-TIM to 10 MHz.  In fact, yours must be a very early model because even digging through old web pages, I can't find any mention of a 30 MHz output.  Don't lose that one, you'll never find another like it!

> Control the NCO is quite simple, via simple protocols, ie 10MHz output is
> such as " $PRTHS,FRQD,10.000.000 ".
> The CW25 TIM, factory default NCO output is 10 MHz, since startup and will
> lock to 1pps when status fixed, the module is running warm to touch at, I
> suppose an ovenised crystal is inside.
> I do not have the CW12, if the module is CW25TIM, it is worthy to get the
> CW12 to save the pain of etching a PCB.

> Pascal Nguyen

Thanks for the info,
Ed