[time-nuts] LTE lite questions

Said Jackson saidjack at aol.com
Sat Nov 22 13:10:41 EST 2014


CC'ing time nuts..

R2 and R3 are stuffing options, see the schematics in the user manual. Typically you don't have to solder anything. The default is set for the low-noise 3.0V to be fed to the DIP-14 tcxo for best performance.

On your question on removing the SMT Tcxo, this is not easy, but possible with a heat gun. Its easy to melt the adjacent switches though when doing that. The RTV over it should just peel off, but we have not tried that yet. There is no way to just remove power to the internal Tcxo unfortunately.

This is why I had suggested the 19.2MHz version for people who want to use the external oscillator option, because that won't beat with your oscillator close-in. I was a bit surprised that so few of those 19.2MHz units sold compared to the significant numbers for 10/20MHz units. In either case I think the resulting beat spurs are typically lower than many other GPSDOs and oscillators have in their spurs, the CSAC with its spurs comes to mind..

Hope that helps,

Sent from my iPad

On Nov 22, 2014, at 6:08, GandalfG8 at aol.com wrote:

> Hi Said,
> Sorry to bother you again, I'm not sure is this is an oversight or deliberate but I've just noticed that R2 has not been fitted to my evaluation board.
> I'm a bit concerned as this will affect power to the external oscillator and R2 would be difficult to fit now that SW2 is installed.
> I may have missed this if it was mentioned on the Time-Nuts list but there's a lot there to look through so thought it best to ask you direct.
> Regards
> Nigel

Sent from my iPad

More information about the time-nuts mailing list