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Electronics => Repair => Topic started by: franzy on August 24, 2019, 02:14:22 pm

Title: ADVANTEST Spectrum R3272 gain defect
Post by: franzy on August 24, 2019, 02:14:22 pm

Hi alls,
I have this spectrum analyseur, and before open, i would like to know if someone has had a similare problem.
When I calibrate TOTAL GAIN, I have a message like:
"calibration signal was not detected Please check CAL OUT signal"
I have tested Call out signal (30Mhz -10dbm) with an other analyser, it is correct.
So when I mesure Call out signal, i have -19dbm before -10dbm.
I think i have problem with atenuators .
What do you think about it ?
Where a can find schematic ?
Regards

Title: Re: ADVANTEST Spectrum R3272 gain defect
Post by: CrazyTiger on August 25, 2019, 02:47:01 am

You can feed the 30MHz -10dBm signal back to the spectrum and measure, but this time vary the input attenuation,if the spectrum measures correctly on a different attenuation, likely the attenuator have a blown pad.

Or set the input attenuation to 0 dB, this should connect the signal directly to the frontend bypassing the attenuator, if it measures correctly, likely attenuator is dead if it measures bad, the next stage is bad

On my R&S FSEB, sometimes the mechanical attenuator relay gets sticky creating bad contact, so just varying the input attenuator setting, to make multiple contacts usually solves it