K3s frequency drift on HF


MICHAEL LANE
 

Hello,
My K3s has developed a drift problem whereby not only does it drift, but the frequency readout goes with it. It seems to be temperature related as  with the fans on auto it was drifting in one direction and when I put the fans manually on top speed it drifted the other direction. Any ideas please?

Mike G1SCT


Robert W5AJ
 

Mike,

 

need bit more information

Normal here on warm up, the K3 does drift in one direction, how much is your rig drifting

The room is lower temperature than K3 and turning fans on does cause (less than 1 hz at WWV 5mhz) drift in other direction

(that’s here in my shack)

 

In preparing for FMT, leave the rig on from time you arise

Don’t put fans in manual before test, leave in normal

also do your pre-calibration checks with WWV same and not after heavy RTTY or FT8 pileup!

 

drift is hardly noted on 160meters, more as you go to higher band.

 

73 W5AJ

 

Robert

Midland, Texas

http://pages.suddenlink.net/w5aj/

 

From: Elecraft-K3@groups.io [mailto:Elecraft-K3@groups.io] On Behalf Of MICHAEL LANE via groups.io
Sent: Monday, June 07, 2021 3:56 PM
To: Elecraft-K3@groups.io
Subject: [Elecraft-K3] K3s frequency drift on HF

 

Hello,
My K3s has developed a drift problem whereby not only does it drift, but the frequency readout goes with it. It seems to be temperature related as  with the fans on auto it was drifting in one direction and when I put the fans manually on top speed it drifted the other direction. Any ideas please?

Mike G1SCT


MICHAEL LANE
 

On Tue, Jun 8, 2021 at 07:51 AM, Robert W5AJ wrote:
Hi Robert, this is not normal drift as much as involuntary QSYing. It is randomly intermittent so is a fault rather than normal drift. Last night I was struggling to have a contest QSO on RTTY before it wandered off.
I’m wondering if it is to to with the VFO encoder but shifting it doesn’t have the affect of making it better or worse. 

Mike


barry NF1O
 

I had that happen to me a while back. some suggested that the up/dn buttons on the mic could do that. I had always used the rear mic connector so did not have up/dn buttons but it did look like thats what was going on. I plugged in a mic connector into front mic and problem immediately stopped. Apparently enough dust had collected in the mike port and provided a low enough resistance to cause it. I now use a cover on the mike port.
GL
Barry
NF1O


From: Elecraft-K3@groups.io <Elecraft-K3@groups.io> on behalf of MICHAEL LANE via groups.io <michael.lane3@...>
Sent: Monday, June 7, 2021 4:56 PM
To: Elecraft-K3@groups.io <Elecraft-K3@groups.io>
Subject: [Elecraft-K3] K3s frequency drift on HF
 
Hello,
My K3s has developed a drift problem whereby not only does it drift, but the frequency readout goes with it. It seems to be temperature related as  with the fans on auto it was drifting in one direction and when I put the fans manually on top speed it drifted the other direction. Any ideas please?

Mike G1SCT


MICHAEL LANE
 

Hi Barry, that sounds unlikely but I will investigate, I like you use a headset in the rear Jack. I was leaning towards the encoder, I thought maybe the mouse wheel via N1MM but I disconnected the USB and it still happened.  I will check that when I get home.
Mike


barry NF1O
 

I was very surprised as well, not something that is expected. several people suggested dirty up/dn switches and after looking, i found the only place they could be was the mic connector.  The frequency shifting was constant, very slow but always there. I plugged in a mic connector with no mike or anything connected to it. The problem immediately stopped and has not returned.  (I keep a dust cap on all the time now)
very strange, but in my 35 years working in engineering I have found the occasional solution that did not appear to make sense.
good luck.
73
Barry NF1O


From: Elecraft-K3@groups.io <Elecraft-K3@groups.io> on behalf of MICHAEL LANE via groups.io <michael.lane3@...>
Sent: Tuesday, June 8, 2021 8:41 AM
To: Elecraft-K3@groups.io <Elecraft-K3@groups.io>
Subject: Re: [Elecraft-K3] K3s frequency drift on HF
 
Hi Barry, that sounds unlikely but I will investigate, I like you use a headset in the rear Jack. I was leaning towards the encoder, I thought maybe the mouse wheel via N1MM but I disconnected the USB and it still happened.  I will check that when I get home.
Mike


MICHAEL LANE
 

Hi Barry,
The mic socket itself does not appear to be the problem but bad drift was an issue tonight, it only affects the receiver which is on the main VFO and the VFO lock stops the drift and when switched back on it resumes. This seems to be pointing to the encoder although I don't understand how temperature change effect the direction of the drift.

Mike


MICHAEL LANE
 

Hi all, 
problem now resolved, temperature was a red herring! Revisiting Barry’s theory I pulled the fist mic plug out which has no buttons incidentally, and the frequency started to count down. Whilst pondering what it could be I could see the VFO knob very gradually moving. It would seem that the felt washer has worn and the VFO knob it not balanced in weight. In certain positions it is worse than others. Loosen the knob a pushed it back a little, so I will see how it goes. I did video it but not sure how to upload. 

thanks for all the help,
Mike G1SCT 


barry NF1O
 

glad you got it fixed.
73
Barry
NF1O


From: Elecraft-K3@groups.io <Elecraft-K3@groups.io> on behalf of MICHAEL LANE via groups.io <michael.lane3@...>
Sent: Wednesday, June 9, 2021 12:55 AM
To: Elecraft-K3@groups.io <Elecraft-K3@groups.io>
Subject: Re: [Elecraft-K3] K3s frequency drift on HF
 

Hi all, 
problem now resolved, temperature was a red herring! Revisiting Barry’s theory I pulled the fist mic plug out which has no buttons incidentally, and the frequency started to count down. Whilst pondering what it could be I could see the VFO knob very gradually moving. It would seem that the felt washer has worn and the VFO knob it not balanced in weight. In certain positions it is worse than others. Loosen the knob a pushed it back a little, so I will see how it goes. I did video it but not sure how to upload. 

thanks for all the help,
Mike G1SCT