Tuning The Elecraft K1 Frequency Display Using W1AW or WWV and Spectrogram.

Started by gil, August 12, 2012, 12:42:31 am

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gil

Hello, I know this is a bit specific, but I am sure some new K1 builders might find it useful.

I heard about Spectrogram on the Elecraft email reflector, the PC version. Problem is, I wouldn't touch a Microsoft product with a ten foot pole. To my surprise though, there is an iPod application for $9.99. Bingo!

First I needed to set my transmit offset correctly. I first did it by ear, but it turns out that I was 50Hz off. Pretty good, but I like things to be "just so." I removed both top and bottom covers and flipped the tone switch to "Tune." I could hear the faint tone. I placed my iPod running Spectrogram near one earbud and could see the tone on the screen appearing and disappearing as I removed or replaced the earbud. I slowly turned C13 until the line perfectly aligned with the 600Hz mark. Next, I made sure my sidetone was also set to 600Hz under the Stp menu. Don't forget to flip the switch back to "Oper." Et voila!

To make sure your display shows the correct frequency, You can listen to either W1AW broadcasts on 7,047.5 or 14,047.5 kHz. See the ARRL web site for schedules. With Spectrogram on, you move the tune pot until you align their 750Hz tone with the same frequency on the screen. Then you go to the Cal menu and use the up/down buttons to set the displayed frequency to end in 47.5.

With WWV on 10mHz (30m), you move the tune pot until their tone matches your sidetone frequency on the screen, meaning, if you did set your tone to 600Hz, you move the tuning pot until their "main" tone (thicker line) shows on the 600Hz mark on the screen. If your display shows 10,000.6, you're right on.

I used W1AW first, then verified my setting with WWV. I was spot on. For $9.99, you get the assurance of being right on frequency. You can also use your app for zero-beating any station you hear. Priceless  ;)

gil

Reply from Don W3FPR, from the Elecraft reflector. Thanks Don!

Gil,

As far as I know, you are close to correct, but why tune W1AW to 750 Hz when you have set your BFO and TX offset to 600 Hz?

You can use any FFT based audio spectrum analyzer in place of Spectrogram.
The procedure is:
1) Tune in "band noise" (no signals are desired)
2) Switch to FL3
3) Adjust the BFO trimmer to place the filter passband centered at you chosen sidetone pitch.
4) turn the switch on the bottom to TEST and tune the TX OSC trimmer at the back to set the tone at your sidetone pitch.
5) Check to be sure the STP menu parameter is set to your preferred sidetone pitch.
6) Set the operating frequency for each band - one can use W1AW transmissions, or other sources of known frequency.  I have a very accurate frequency counter, so I set the power to 1 watt and measure the frequency of the transmitted signal.

You may put this information on you blog - I did not send it to the reflector

73,
Don W3FPR