[Elecraft] K2 automatic tuner

[Don Wilhelm]

William,

That indicates that either you have a bad coax between the K2 and the 
tuner, or the tuner's SWR meter has a problem.

If you have an antenna analyzer, connect it to the same coax that you 
connect to the K2 and see what it indicates.

It may be that the KPA100 wattmeter could stand some refinement, but 
that would take some special dummy loads - I use a 25 ohm and a 100 ohm 
dummy load to refine the setting of capacitor C1 - the SWR indication 
should be the *same* for each of these loads if C1 is set to exactly the 
null point.  That is more precise than finding the voltage null.
After doing that adjustment, I set R27 to show SWR at the 2.0-1 point 
and then set R26 to indicate the power while driving a 50 ohm dummy load 
and an external wattmeter that I know is properly calibrated.

73,
Don W3FPR

On 7/20/2016 2:02 PM, William at zendamateur.nl wrote:
> When i just connect a 50 ohm dummy tot he K2 it says 20   1.0 - 1
>
> So I think it is right calibrated :-)
>
> Regards William
>
> -----Oorspronkelijk bericht-----
> Van: Don Wilhelm [mailto:donwilh at embarqmail.com]
> Verzonden: woensdag 20 juli 2016 19:50
> Aan: William at zendamateur.nl <pe1bsb at zendamateur.nl>;
> Elecraft at mailman.qth.net
> Onderwerp: Re: [Elecraft] K2 automatic tuner
>
> William,
>
> Thanks for that clarification.  Connect the KPA100 to a good dummy load and
> do the wattmeter alignment and calibration as indicated in the
> KPA100 manual page 48 - see the SWR Bridge Null Adjustment and also the
> Power Calibration sections.
> You must do the bridge null before attempting the Power Calibration.
>
> 73,
> Don W3FPR
>
> On 7/20/2016 1:41 PM, William at zendamateur.nl wrote:
>> Thanks Don fort he answer,
>>
>> The display is ok
>>
>> I just did not put every thing there
>>
>> It says :  20    2.0  - 1
>>
>> So I enderstand that as a swr of 2.0 ???
>>
>>
>>
>> -----Oorspronkelijk bericht-----
>> Van: Don Wilhelm [mailto:donwilh at embarqmail.com]
>> Verzonden: woensdag 20 juli 2016 19:27
>> Aan: William at zendamateur.nl <pe1bsb at zendamateur.nl>;
>> Elecraft at mailman.qth.net
>> Onderwerp: Re: [Elecraft] K2 automatic tuner
>>
>> William,
>>
>> Are you reading the K2 display correctly when you do a TUNE?
>> Normally the K2 displays the power on the left and the SWR on the right.
>> The power is normally 20 watts and the SWR will be shown as 2 digits
>> (1.0 through 9.9).
>> In other words, you will see something like "20  1.0".
>>
>> If the KPA100 wattmeter is not indicating properly, it may be that
>> diodes
>> D16 and D17 have become damaged, or it may just be that the wattmeter
>> needs to be balanced and calibrated.
>>
>> 73,
>> Don W3FPR
>>
>> On 7/20/2016 12:33 PM, William at zendamateur.nl wrote:
>>> Hi group,
>>>
>>> Perhaps it's a silly question, but i don't understand something.
>>>
>>>     I have a K2 100 watt but I don't think any other set will make a
>> deferens.
>>> the set is connected to a tuner (AT-100Pro LDG) and it tunes as far
>>> as I can see ok.
>>>
>>> But now what I notice, when I tune the tuner tunes to swr 1.1 so that
>> seems
>>> to be ok, but my K2 gives me 2.0    1.
>>>
>>> Does that mean my K2 sees a swr from2.0 whil my tuner says  it is 1.0 ??
>>>
>>
>>
>
>
>