[Elecraft] KXV3 Issues - endless frustration

[Oliver Dröse]

Hi Udo,

the mW calibration never worked on my K3 if using the K3 Utility. Don't 
ask me why! Was the case right from the beginning. But it works 
trouble-free when doing it the manual way from the radio front panel. 
Try that as an alternative!

It seems to me settling power in the calibration routing just takes 
longer than the Utility will wait while the front panel procedure does 
not have that limit as you're in control of it.

Concerning the other issue (gain difference) just a few ideas: checks 
internal preamp settings, check filter setting (do both RX have 
comparable filter gains set), a.s.o.

73 & gl, Olli 'BQA

Contest, DX & radio projects: http://www.dh8bqa.de


Am 19.06.2015 um 22:50 schrieb Udo Langenohl - DK5YA:
> Just got my KXV3-B as a replacement of the former KXV3-A. Installing 
> complete after 1 hour. Removing the back panel makes things much 
> easier btw. But there's an issue. The 1 mW calibration fails. Thats 
> what the Elecraft Utility says:
>
> Elecraft K3 Utility Revision 1.13.5.9
> OS Version 6.1 Build 7601 Windows 7/Windows Server 2008 R2
> K3 MCU revision 05.26. RS-232 speed 38400 bit/s.
> Starting 1 milliwatt calibration
> Calibrating at 1.900 MHz
> Calibration power settled at " 1.800.00;"
> Elapsed time: 5 seconds
> Tx Gain calibration failed because transmit power did not reach the 
> expected value
> 1 milliwatt calibration failed
>
> Wait, there's more to come. I made a replacement because my guess was: 
> KXV3-A has a damage.
> I use my K3 mostly on VHF with transverters, especially on 144 MHz 
> EME. I'm running a Xpol configuration with 4 antennas on 144 EME with 
> two identical transverters, both in phase and locked by a common 
> external LO with 10 MHz GPS control for Hpol and Vpol.
> HPol RX is fed to the KXV3 XVTR In/Out while Vpol is fed to the AUX RF 
> input. I can listen to both planes simultaneously using diversity 
> receive.
> But something very strange happens when I compare signals on both 
> planes. I have a 144 MHz beacon nearby (just 25 miles away). That 
> beacon is running 8 W on a Hpol antenna. On my Hpol (main RX via KXV3) 
> input this beacon comes up to S9+35 dB while on Vpol (second RX via 
> AUX) it's endstop (S9 +60dB). The beacon is in the line of sight, 
> there's a lot of RF on my location from this beacon.
> It's definetely not from the transverters or from mismatched antennas 
> because when I change inputs and connect the Hpol transverter output 
> to the AUX RF it's suddenly S9 +60 dB too. Both main and sub RX are 
> exactly in the same configuration, filters, bandwidth, NB Off, etc..
> I checked S/N on KXVR3-A (old board) and AUX few days ago with my 
> HP8664A signal generator.
> On 28.200 (TVTR IF) I measured:
> Top values:
> KXV3-A TVTR IN:       -10dBm = S9+25dB
> AUX IN:             -10dBm = S9+60dB (!)
> KXV3-A TVTR IN:          +3dBm = S9+60dB
> Huge difference of at least 13dBm
> Low values:
> KXV3-A TVTR IN:      -134dBm = signal detectable
> KXV3-A TVTR IN:         -140dBm = none
> AUX IN:                -140dBm = clear signal detectable
> Again a difference of at least 6dB or even more.
>
> Now, with the new KXV3-B it's even worse, at least 22 dB difference 
> between the AUX IN and TVTR IN.
>
> What the heck is going wrong here? MAIN RX dead?
>
> 73 Udo, DK5YA
>