[Elecraft] A new Elecraft product?

[Don Wilhelm]

I am hearing that you have an external reference that takes some time to 
warm up after you turn it on, and that causes the K3 to move frequency 
with the warmup drift of the external reference.

If the external reference is stable when the K3 is turned on, there is 
no need for the K3 to ignore the external reference.

If the K3 were to ignore the external reference for 15 to 20 minutes 
after the K3 is turned on, then it would have to do the same thing after 
every power cycle.  If I were using an external reference, I would not 
want the K3 to do that.  If I use an external reference, I would want 
that reference to be accurate at all times, I think the best answer is 
to power the reference continuously.

As a parallel, the high stability 10 MHz reference oscillator in my 
universal counter is powered whenever the counter is plugged in - when I 
use the front panel switch to turn the counter on, I can trust its 
accuracy without waiting for it to warm up.  If I used an external 
reference with the K3, I would want the same results.

73,
Don W3FPR

On 10/16/2014 8:39 AM, Brian wrote:
> Don,
>
> The issue isn't whether the TCXO is an improvement over the standard.
>
> The issue is whether the TCXO is good enough for some of the wide 
> range of uses the K3 is put.
>
> What you are hearing here is that it isn't.  Elecraft has responded 
> with the external locking option.  That option, being a discontinuous 
> correction, one has some significant disadvantages to some.
>
> My original posting on this issue was related to the locking option.  
> It only seemed reasonable to have it do a sanity check on the 
> difference between the internal and reference oscillator implied 
> correction before doing a correction.  Why do the correction is the 
> external oscillator is warming up and 250 Hz off initially?  The K3 
> also drifts during warmup with both the standard and TCXO.  This 
> amounts to between 20 and 50 Hz (@ 10 MHz) for the first 15 minutes.  
> Why do the correction until the K3 has is relatively stable.  Perhaps 
> the external locking should not be done for say the first 15 minutes 
> after K3 turn on?
>
> 73 de Brian/K3KO
>
> On 10/16/2014 12:06, Don Wilhelm wrote:
>> Brian,
>>
>> The High Stability TCXO (1 ppm) is not a separate Elecraft product - it
>> is an option for the K3 offering better specs than the stock TCXO (5ppm)
>> - yes, both are a TCXO.
>>
>> The temperature stability was found to be far better than the 1ppm
>> specification without the temperature compensation routine, so
>> implementation of that K3 routine was dropped from the plan (and also
>> from the manual).
>>
>> 73,
>> Don W3FPR
>>
>> On 10/16/2014 7:39 AM, Brian wrote:
>>> Ken,
>>>
>>> There is an Elecraft product called the TCXO. It is capable of
>>> temperature stabilization BUT Elecraft has not implemented that 
>>> function.
>>>
>>> Perhaps though should be given to implementing the temperature
>>> compensation capability.  My understanding is that there is some
>>> difficulty in doing that and maintaining low phase noise.
>>>
>>
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