Noisy / Intermittent / Bad tuning potentiometer?
-Greg
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----- Original Message -----
From: ferrymanr
To: hp_agilent_equipment@...
Sent: Sunday, August 28, 2011 4:26 PM
Subject: [hp_agilent_equipment] 8558B centre frequency wildly unstable above 1250MHz
I have an 8558B which becomes totally unstable if the centre frequency is set above about 1250MHz at any span setting. If the span is sufficiently wide it is clear that the SA it is covering perfectly up to about 1550MHz or 1600MHz with some loss of sensitivitity at the top end. When the centre frequency is set above about 1250MHz the frequency display becomes random from blank up to some random number. This indicates to me that the control voltage is unstable above that frequency setting. The display looks like it is jumping all over the spectrum (have I discovered 'spread spectrum').
Any suggestions as to a likely cause or common problem before I delve into the murky depths.
Thanks
Dick G4BBH
