[Elecraft] K60XV Builder Alert: TUNE mode issues with KAT2

[Ken Wagner]

wayne burdick wrote:

> If you have a K60XV (60 m/XVTR interface) installed in your K2, *and* 
> a KAT2 (internal ATU), you may notice two problems in TUNE mode. These 
> only occur if you're using the low-power (0 dBm) transverter interface 
> on the K60XV. Both have simple work-arounds:
>
> 1. If the KAT2 is in either of its autotune modes (AUTO or ALT), the 
> holding the TUNE button drops power output to 0.2 milliwatts maximum 
> in low-power (LP) mode. You can override this behavior by simply 
> holding DISPLAY along with TUNE. You can also use the menu to change 
> configure the KAT2 for any mode other than AUTO or ALT, but this is 
> less convenient.

Same thing happens if there is a KAT100 attached. Power our says .20 LP 
when Tune is pressed and ATU in "Auto."

>
> 2. In some cases the LM358 op-amp on the KAT2 can load down the 
> K60XV's RF detector (at the emitter of Q2), preventing the K60XV from 
> developing a full 0 dBm (1 milliwatt) signal at the low-level 
> transverter OUT jack. To correct this, change R6 on the KAT2 from 47 
> ohms to 470 ohms. This will have a negligible effect on normal use of 
> the KAT2.

With the KAT100, I was able to initially get "full" 1 mw out as 
indicated on the K2 (ATU in CAL). Over a period of about 15 seconds the 
power out dropped to about 0.95 LP indicated.

73,
Ken Wagner
K3IU