[Elecraft] K3: Main RX gone deaf

[Graham g3tct]

Hi Udo
Before you start tearing the rig apart, two ideas:-

-is there a big difference for weak signals of say S4?
-if not, it may just be the S meter calibration that needs attention.
-if so, preamp on for either? Att on for main?

HTH
Graham

On 19:59, Udo Langenohl - DK5YA wrote:
> Gentleman,
>
> I'm struggling with a Main RX vs. Sub RX issue. My Main RX is rather 
> deaf compared to the Sub RX. I see at least 23.5dB attenuation between 
> Main RX and Sub RX when comparing highly stable signals from my signal 
> generator (HP8664A). This is only for ANT1/2 vs. AUX-IN!
> Example:
> -33dBm on 28.500
> into AUX-IN (SUB RX): exactly 59 +40dB
> into ANT 1 (Main RX): 59 +15dB
> into ANT 2 (Main RX): 59 +15dB
>
> I've checked all the usual suspects (pin diodes):
> D1 and D5 on the KXV3A: o.k.
> Each and every pin diode on the SUB IN board: o.k.
> D5 on the Main RX board: o.k.
>
> This is a K3 #59xx with almost everything inside money can buy.
>
> My second K3 (serial #39xx) does not show this strange behavior. Main 
> RX and SUB RX show exactly the same values on ANT1/2 and AUX IN. 
> -33dBm is 59+40 on MAIN and SUB RX, no matter if Ant1, 2 or AUX IN.
>
> Any idea? I'm searching for weeks now and I'm close to give up.
>
> Udo, DK5YA