HP8593A trouble
The analyzer first showed problems after not being turned on for about a year. It would still work if left on for a while and then
power cycled. I was told to check the lithium memory battery which I did and found it to be low. I changed the battery but that
did not seem to make any change in the units operation. Over a period or maybe year or so of use it would initially power up with
the display image out of sync. That was easily corrected with the cal functions. Each time it was used I would find various
functions did not work. For a while it seemed to work fine up to about 2 GHz but no higher. Even when the frequency was entered
higher than 2 GHz it would still display a maximum for 2.xxx GHz.
Initial boot up display:
Shows Opt 001 which info I have indicates 75 ohm but input connector is designated 50 ohm
When a frequency is entered above about 2 GHz the display will show various frequencies around 4 GHz.
Will properly display any frequency selected under about 2 GHz.
When it first started showing problems the analyzer would work ok
below the 2 GHz range. Now after setting for a few years I have not
been able to get a signal display at any frequency.
When a calibrate is initiated it will run for several minutes as if all is well.
In order to get the cal to run "FREQUENCY -37 Hz" I found this in the
troubleshooting section.
Cal fail message with "Service Request 110" when cal has finished.
I find no reference to what SRQ 110 indicates in the info I have.
No signal detected with a -20 dbm 100 MHz signal connected.
I have gone through all the troubleshooting test in the manual but the manual
I have doesn't exactly jive the this unit.
I can see a 300 mhz signal on the cal port and also a signal out from the comb connector.
I guess it's logical the unit can not calibrate if the input can not see an input signal.
If the input has ever been overloaded it was before I got it.
All troubles started after the unit set idle for an extended period and the battery voltage
dropped to less than 2 volts.