Re: [Elecraft_K3] K3S - KTC03-1 Frequency Stability

Jim - N4ST


Thanks for your input.
Yes, I have been thinking about a GPSDO and the External Reference board.
I don't align my rig based on the other guys transmit frequency, but I do adjust my transmit frequency to match his.
That is the semi-frustrating thing. The vast majority of the stations will be within 10-15 Hz of each other on 6-meters, with just an occasional outlier.
They are managing to stay on frequency just fine. Then again, maybe they are doing the same thing as me. 😉

Off Topic
Microsoft's grammar checker wants me to change "adjust my transmit frequency" to "adjust me transmit frequency", and it's not even talk like a pirate day.
Jim - N4ST

From: []
Sent: Thursday, June 15, 2017 12:20

Subject: Re: [Elecraft_K3] K3S - KTC03-1 Frequency Stability

If I was using a mode that requires high frequency accuracy and stability, two issues come to mind. I would want a house frequency standard on my end, and whatever K3 option is required to lock the radio to that standard. Surplus GPSDO and Rubidium standards are available in the $150 range. The other question is what is being used on the other end? Can you assume the other guy you are trying to work is on frequency?

I have been running a Efratom Rubidium standard 24x7 for over 15 years and it is still within a few parts in 10 to the 10th compared to my GPSDO. I don't run my two other Efratom Rubidium oscillators all the time (2 QTHs or I wouldn't have so many), and they come up within the same level of accuracy within 10 minutes after turn-on.

Most of this type of surplus equipment comes out of cell phone sites, and would at least eliminate having to fiddle with frequency accuracy on your end.

Rob, NC0B

On Jun 14, 2017, at 3:17 PM, 'Jim - N4ST' [Elecraft_K3] <> wrote:

Thanks Wayne, but I’ve had this K3S for over a year and a half and never noticed the problem until I started working 6M MSK144.
I couldn’t understand why I could hear the meteor scatter pings, but wouldn’t decode. The max freq tolerance for MSK144 is 200 Hz.
When I figured out I was off frequency, I did a REF CAL adjustment and was dead on.
Then I noticed that from day-to-day I could be 50Hz-70Hz off, even for a warmed up rig.
I went through setting the REF CAL several different times, using different techniques and all seemed to work, but within a few days I would be off frequency again, by 50 Hz or so.
Now I just monitor for a few MSK144 pings and see where the majority are transmitting and offset my TX frequency by the appropriate amount and I’m good to go.

Especially easy now during e-skip when the signals are readily available.

Jim – N4ST

From: []
Sent: Wednesday, June 14, 2017 10:43
Subject: Re: [Elecraft_K3] K3S - KTC03-1 Frequency Stability

If that is true, we’ll replace it immediately. Please contact customer support.


On Jun 13, 2017, at 9:10 PM, 'Jim - N4ST' [Elecraft_K3] <> wrote:

I guess I paid $119 for a 1ppm oscillator upgrade that doesn't have "typical" (0.5ppm) performance.

Jim - N4ST

From: []
Sent: Tuesday, June 13, 2017 12:34
Subject: [Elecraft_K3] Re: K3S - KTC03-1 Frequency Stability

Hi Jim,

Have you learned anything more on this issue?


Posted by: Wayne Burdick <>

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