[Elecraft] 10 MHz external reference - GPSDO

[David Anderson]

Hi Oli,

I agree it looks like there is no point in paying for the TCXO-3 if you have a reliable constantly available 10 MHz external reference. Perhaps they recommend the better TCXO as a better fallback if for any reason the external ref is not available, I can't think of any other reason for it.

73 from David GM4JJJ

> On 13 Mar 2016, at 09:27, Oliver Dröse <droese at necg.de> wrote:
> 
> Thanks Ed.
> 
> I don't have a problem understanding how the TCXO's work. Maybe I was not clear enough. ;-) Taking your example from below, having only the TCXO-1 it is surely *not* drifting 140 Hz at 28 MHz within the 4 or 5 seconds of the EXREF update cycle (same as the TCXO-3 will not drift by 28 Hz in that time), otherwise the K3 would be a *very* crappy radio. ;-) Think you are missing the time domain here. ;-)
> 
> So my question still stands: What's the real value of the TCXO-3 over the TCXO-1 when using the K3EXREF? Unfortunately I do neither have the measuring equipment to measure below 1 Hz drift (and I'm not seeing that amount with my TCXO-1 only K3) nor a TCXO-3. So will the radio drift by 0.0014 Hz with the TCXO-1 + K3EXREF within those 4 seconds and the TCXO-3 will bring it down to 0.00028 Hz? Then I'm probably fine with the TCXO-1 and even the most sophisticated digital modes available. ;-)
> 
> 73, Olli - DH8BQA
>