Hello,
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My favourite instrument, an HP8563E SA, seems just to have lost 30 dB sensitivity when input signal frequency is passing 2.8 GHz.?
At the beginning of the day, it worked perfectly, then signal all of the sudden dropped by 30 dB.?
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Not suspecting the analyzer, I worked a bit more on the signal generator that I was fixing, but nothing helped. Shutting down both instruments and restarting them brought things?back?to normal for a short while, but then sensitivity dropped again.?
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When realizing the SA had problems, I tried running the CAL routines (CAL button) since a restart previously had brought the unit back, but nothing helped. Restarting after a while of cooling didn't help either.
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My big fear is that the first mixer (A10 RYTHM)? is damaged in some way. Anyone had this before? Only found some 60 entries regarding the 8563 specifically and couldn't find anything.
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Other suggestions??
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Looking at the specifications, input damage level with 10 dB attenuation is at 30 dBm so I figure even with input attenuator set to 0 dB, the input should survive +20 dBm - that's a lot of power (for some) and I can't really see where I could have generated that. Always use a DC-block at the front.
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Any suggestions or comments appreciated - I really keep my fingers crossed this instrument can be saved!
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Regards,
? Staffan
