[Elecraft] VFO Cal measurements for #2006/Rev B
Rod N0RC
[email protected]
Thu Jan 2 12:03:01 2003
Folks,
After my original post about VFO/DIAL calibration I re-adjusted
C22, using the "5th harmonic, beat against 20MHz WWV" method.
Then, I made sure the K2 and 746pro were powered up for about
one hour, and made a new calibration table (below). From the
data you can see, mastering the art of C22 adjustment can have
dramatic effects upon your dial accuracy. If you don't have a
precision frequency counter alignment to 20MHz WWV is a good
substitute.
Both rigs were in CW mode as I achieved the best zerobeat
possible against WWV.
Then, using the 746 as a "signal generator" [into a dummy load,
at low power] I zero beat the signal on my K2.
NUMBERS IN PARENS AFTER RE-ADJ. OF C22
NOTE THE DIFF WORST CASE ERROR < ~150Hz!
Test 746 K2 K2
Freq zerobeat zerobeat zerobeat
(kHz) to WWV to WWV to 746
2500 2500.003 -- --
3560 -- -- 3560.05
(3560.00)
5000 5000.006 -- --
7040 -- -- 7040.02
(7039.99)
10000 10000.012 10000.02 --
(10000.00)
10116 -- -- 10116.00
(10115.99)
14060 -- -- 14059.97
(14059.98)
15000 15000.018 14999.98 --
(14999.99)
18080 -- -- 18079.94
(18079.97)
20000 20000.024 19999.78 --
(19999,96)
21060 -- -- 21059.76
(21059.94)
24900 -- -- 24899.72
(24899.93)
28060 -- -- 28059.70
(28059.92)
CONCLUSIONS (BEFORE C22 RE-ADJUSTMENT)
80-20m K2 dial after warm-up, dial is accurate to
within ~50Hz or less
17m K2 dial after warm-up, dial is accurate to
within ~80Hz or less
15-10m K2 dial after warm-up, dial is accurate to
within ~350Hz or less
----- Original Message -----
From: "Rod N0RC" <[email protected]>
To: <[email protected]>
Sent: Sunday, December 29, 2002 12:05 PM
Subject: [Elecraft] VFO Cal measurements for #2006/Rev B
> Folks,
>
> After reading the posts about VFO calibration I got to wondering
> how my K2 looked. So, I powered up my k2 and 746pro for about
> one hour, then made the calibration table below.
...