[Elecraft] Photos of K4 prototypes

[Grant Youngman]

Yes, that’s what it would be.  Just commenting that it may be an option and not part of the basic radio.

Grant NQ5T
K3 #2091 KX3 #8342

> On May 17, 2019, at 11:39 AM, Kevin Cozens <kevin at ve3syb.ca> wrote:
> 
> On 2019-05-17 9:54 a.m., Grant Youngman wrote:
>> I noticed the "REF IN" connection has a hole plug in it.  I wonder if this means it’s an add-on option?
> 
> Hm... Possibly a future input for a 10 Mhz external frequency standard signal?
>