[Elecraft] K3 with 2m tvtr - power control feature request

[Don Wilhelm]

Graham,

You say you have measured the input power to the K144XV and it is a max 
of 0dBm and a minimum of -7dBm.  If that is incorrect, then my 
conclusion (following) is wrong.

A difference of 7dB should produce 1/20 of the power developed at 0dBm - 
based on 10 watts output, you should obtain 0.5 watts output with the 
-7dBm input.

So my conclusion is that the K3 is "doing the right thing", but your 
K144XV is not.  Perhaps there is some sort of oscillation in the K144XV 
that is causing your problem.

We obviously don't have all the answers here, so I recommend you contact 
K3support because they have access to the designers and production test 
folks to seek out an answer for you.

Do you have any way of determining the output frequency on 2 meters? 
That may be helpful information for support.

73,
Don W3FPR

On 7/6/2017 10:13 AM, Graham Kimbell wrote:
> 
>     * the max output is supposed to be 10W, but measures 7W even after
>       calibration - seems wrong but I can cope with this
>     * the minimum power is 5W but should be down 10dB on the max, ie
>       0.7W.  This is a problem because I need about 1W to drive the
>       microwave tvtr.
>     * the XV config that allows setting the 28MHz input to the tvtr has
>       been checked and is exactly the 1mW (0dBm) default.  With the
>       power control set to minimum it measured -7dBm.
> 
> So it appears that the internal 2m xvtr has too much gain, and there 
> does not appear to be any way to reduce the power output below 5W.  Is 
> there any chance of making this possible?