No, it doesn't have anything to do with the 2nd LO. There's a
gain-adjustment stage that isn't responding properly somewhere -- either in
the IF amp section, or in the RF attenuator itself.
Try putting the calibrator onscreen (CF 20 MHz, SPAN 100 kHz, REF LEVEL -10
dBm) and hitting the up and down arrows to step the RF ATTEN setting from 10
to 70 dB. The calibrator's amplitude shouldn't vary more than a dB at any
point. If it does, then that is probably what's causing the self-cal to
fail. If it remains steady at all RF attenuator settings, look for the
problem in the IF gain-step control circuits in the display section.
-- john, KE5FX
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-----Original Message-----
From: hp_agilent_equipment@...
[mailto:hp_agilent_equipment@...]On Behalf Of Jim Popwell Jr
Sent: Sunday, September 27, 2009 12:06 PM
To: hp_agilent_equipment@...
Subject: Re: [hp_agilent_equipment] HP8568B Error Correction Routine
failure
it looks as if the analyzer is telling you to adjust the 2nd local
oscillator amplitude down a little to bring it into a range where the
autocal routine can handle it... check the 2nd lo cal section in your
manual
jim
On Sep 27, 2009, at 11:46 AM, ik7jwy wrote:
HI,
yesterday I discovered this trouble on my HP8568B spectrum analyzer.
When I put ON the S.A. everything works fine , the two red leds
INSTR CHECK light for a while, then come back OFF. No error message
on the display.
I perform the two routines RECALL REG 8 and RECALL REG 9 and
everything continues to sounds good.
But, when I go to the Error Correction Routine (SHIFT+W) then I see
the failure. At the end of the routine I see on the display this
message "ADJUST AMPTD CAL", instead of "COOR'D", and all the
parameters (RBW, REF Level and so on) don't come back to the Preset.
You can see here what happens:
If I start again the routine, at the end I get the same result.
Any idea ? Thanks.
Art IK7JWY
