Messages

1

General discussion forum / Low AF output in K3-twins configuration

« on: 2022-10-24, 22:26:23 »

I've had a K3-twins configuration running within my house for years.
Now I seem to have very low AF at the K3-0/mini when I plug in headphones (PHONES front panel jack).  It doesn't seem to materially impact digi modes (but how would I know?).  The AF level at the side SPKR jack is the same.
I made some AF voltage measurements under controlled conditions and measured 0.5V rms at the K3 rear panel SPKR OUT jack.  However after plugging the remote RRC into that jack, the output from the control RRC SP jack is only 3 mV (-45 dB!!).  I've swapped 3.5mm stereo cables between K3 rear panel and RRC/remote input with no effect.
I don't necessarily expect the RRC remote to exactly duplicate voltages, but this is a little much.  I have fairly significant hearing loss as it is, and the low AF impacts CW/SSB operation. 
Control|Radio Settings:
Codec out gain 255
Codec input gain 18
Codec inp preamp YES

Remote|Radio settings
Audio dual-rx Yes
Codec out gain 255
Codec inp gain 0
codec inp atten YES

PS another symptom is that it used to be with the AF control at 9 o'clock on the K3/0-mini the audio input slider (on JTDX) would be about 52-53 dB.  Now I have to turn the AF control to 12 o'clock and the JTDX slider only goes to 40-42 dB.

Any suggestions?  I suspect I have a setting fat-fingered but darned if I can tell what it is.
Thanks,

2

Hardware, Cabling, Installations / Re: Strange audio issue with K3/KPA1500 setup

« on: 2021-01-26, 03:23:33 »

More on this:
All lines to/from the RRC are now choked with Mix 31 toroids, along with all interconnections between the K3 and the KPA1500, and on the output of the KPA1500.
The problem is even worse now, I can't use the amp on 40m at all because the AGC is so unstable.
I did try different software, and interestingly enough using MMTTY on DATA A-AFSK the problem goes away.  But (thanks to a tip) it turns out that if I set CONFIG:AFSK FIL=OFF (no DSP filtering of the transmitted RTTY signal), the problem reappears.  This must be a clue but not to me :-(

3

Hardware, Cabling, Installations / Strange audio issue with K3/KPA1500 setup

« on: 2021-01-24, 00:13:58 »

Working on remoting my K3/KPA1500 via RemoteRig.
If I drive the amp to 500 W or less, everything works great.
But on 40m (and to a lesser extent 30m), anything above 650W or so causes tremendous instability in K3 AGC and RF output.  Some troubleshooting revealed that the audio drive to the K3 was actually varying by up to 5 dB during high power TX on these bands (but not others).  It's as solid as a rock at 500 W and less.  I tried choking the MIC INPUT from the RemoteRig (15 turns of 3.5mm audio extension cable on a 2.4/1.4" Mix 31 ferrite) but that actually made things worse.  It would seem that the problem is somewhere inside the RemoteRig box...has anyone else seen anything like this?