[Elecraft] Freq calibaration

Mon May 5 12:10:02 2003

Hi John,

First program the sidetone frequency using the menu. I set mine to 600 Hz.
Anyway, whatever tone you like will be fine.
Set the amplitude of the sidetone ( St L ) so it sounds about the same amplitude as the signal from your BC221.

Set the K2 mode to CW and the tuning rate to 10Hz/step (max resolution).

Turn on the SPOT function.  You'll hear the steady sidetone.
As you tune the K2 VERY carefully to your signal generator freq, you will hear a beat between the sidetone and the signal.  The beat
sounds like a slow warbbling or pulsing of the 600 Hz tone. The K2 freq readout takes into account the sidetone offset, so the
readout will be exactly right, regardless of the actual sidetone freq you set.  This way you are actually listening to a tone around
600Hz with a varying amplitude.  This is well within the audio bandpass and also easy to hear.

As you tune plus or minus 10Hz from the true "zero beat", you'll notice the warbbling sound changes quite a bit.  By the time you
are off by 50Hz, the beat is so fast you may not even notice it. This makes it easy to read the freq within about 5Hz.

Adjust C22 on the Control Board if necessary and repeat CAL PLL.  It usually takes several passes to get the freq within 10-20Hz.

After calibrating in CW mode, then use Spectrogram  to adjust all your filters.
You can get Spectrogram at:  http://www.hitsquad.com/smm/programs/SPECTROGRAM/
It's a user friendly program and a tremendous aid when aligning the filters.

73/ Bob - AG5Q

----- Original Message -----
From: "john FRANCIS" <[email protected]>
To: <[email protected]>
Sent: Monday, May 05, 2003 6:52 AM
Subject: [Elecraft] Freq calibaration

Hi Chaps,  Wonder if anyone can give me some advice.  I was brought up in the old days when if was so just easy to zero beat the
carrier of an AM or CW Signal.  I must now confes that I am all at sea with USB and LSB.  I have just completed the second stage of
my K2 and want to calibrate the frequency.  Have been reading page 98 on the handbook.  I am using a calibrated signal source ( my
trusty old BC221).   When I have the K2 in LSB mode I am getting 10000.50 kHz  when I go to USB I get a reading of  10000.90 kHz.  I
guess I must be going wrong somewhere.  Shall I just take either LSB or USB and leave it to fate that I am going to be come where
pretty close or what..............Any suggestions/help greatly appreciated (I get and entirely different error reading on 7000 kHz.

73's  John  G3LWI

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