[Elecraft] K3XREF Question

[Don Wilhelm]

Bob,

You can use a 10 MHz Rubidium standard, or for even more accuracy, the 
Trimble Thunderbolt.
The Thunderbolt requires a GPS antenna.

73,
Don W3FPR

On 2/13/2013 7:55 AM, KD7YZ Bob wrote:
> Howdy K3' people:
>
> I have the K3XREF board and would like to get a device to use with it.
>
> What is suggested? And what external antenna goes with it?
>
>
> thanks
>
>
>