[Elecraft] K3: Odd ALC behavior

[Terry Schieler]

I have been watching this thread carefully since it began, and, combined with my experiences over this past weekend, am now more confused than ever.  Don, W3FPR recently (again) gave very succinct instructions for getting a good starting audio point for the ALC readings.  I had previously not been able to get the "four bars solid, fifth bar flickering" on my K3S for JT65 for weeks now, no matter what I did.  Bought all the books and read all the articles (Yes, they reference rigs that work differently than my K3S.  Understood.  I get it)  Yesterday I decided to follow Don's instructions (as bolstered by those from Bob, K4TAX).  Thanks to both fine gents.

I set:
K3S Mode to Data A
Band: 20 Meters (14.076)
Windows 7 Audio level OUT from computer to about 50% of scale (USB CODEC)
Line-IN level on the K3S to 30
PWR slider in the WSJT-X software to about mid-range
Set the K3S power out to 30 with rig's PO control

During a TEST transmit (using the TUNE button in the software), I adjusted the WSJT PWR slider (downward) on the software to finally achieve the four bars solid and fifth bar flickering.  I then switched to normal TX, the ALC reading held fast (four solid fifth flicker) and I made a couple of QSOs.  Life was good.  Power was still at 30, COMP 0 as set.  Seemed that Don and Bob's comments were spot on.  I thought my K3S was good to go for all K3S digital modes, so I touched nothing.  Then I changed bands with the K3S band switch to 15 meters.  Did a test TX on 15 with the Mode (Data A),  Power Out (30) and Comp (0), Software PWR slider settings still untouched.  But upon *normal* TX on 15 M the ALC had jumped to 6 solid bars.  Nothing I tried would get it back to the desired "4 solid+5th flicker" on 15M. 

Then I went back to 20M.  But, the ALC there had also changed and was now 6 solid bars.  It had changed somehow.  Power out still 30, Comp 0, etc.  Also, now the WSJT PWR slider had moved back up above its previous mid-scale settings as well.  I had carefully touched nothing but the BAND and TX TEST switchs on the K3S.

Aren't the DATA A settings saved per band after doing these adjustments for digital modes?  Why would a simple band change alter the rig's ALC setting as well as the PWR slider in the software?  Did the new Freq somehow change the Window's Line Out and the software's PWR slider?  Should I expect to have to reset the settings every time I use one of the JT and FT digital modes?

I think I'll try bouncing signals off commercial tow boats on the Mississippi River instead.  Must be easier.  "CQ the Rhonda May.......Calling the Rhonda May, Over".     ;o)

73,  Terry W0FM


-----Original Message-----
From: Brian Hunt [mailto:huntinhmb at coastside.net] 
Sent: Saturday, August 05, 2017 3:02 PM
To: elecraft at mailman.qth.net
Subject: Re: [Elecraft] K3: Odd ALC behavior

Here are some spectrum photos from the tune signals of both FLDIGI and WSJT-X 1.8.  All three are essentially identical showing some low level sideband noise +/- 30 kHz and down > 60dBc.  There's no apparent difference in the spectra between pumping and non-pumping ALC, as Wes reported.

http://www.pbase.com/brhunt/spectrum_photos

Enjoy!

73,
Brian, K0DTJ