| Electronics > Repair |
| Advantest R3273 / R3267 Repair |
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| chick0n:
I think the culprit is in the 2nd Mixer Stage. When I Power the whole RF-Block with the Voltage Filter (11.5Volt), EXCEPT for the Blue Cable over the 91Ohm Resistor (Where I inject 12.5V). The Analyzer shows me the -10dBm Cal Signal as -21dBm (Uncalibrated). This is the same, as if I Power the whole block with 12.5V. With this, I can get the Analyzer to Self Calibrate... This is the BIAS voltage for the "E5" IC (I think this is a Minicircuits ERA-5 MMIC. Is it?) The Problem is, the ERA-5 Datasheet says, it needs about 5V BIAS Voltage. So with 11 to 12V over the 91Ohm Resistor, it should be about 5V at Pin3 of ERA-5. BUT I measure between 9.7 to 10.4 Volts at Pin3. So ERA-5 is toast? The resistor measures OK. |
| Gyorgy Albert:
@jjoonathan I am not mastering python, but what I understand that you have identified the eeprom structure, which holds the frequency calibration data. Can you detail a bit, how did you find that? And what I concluded: you removed the eeprom from the RF deck, and read out the content. After your RF path (attenuator) measurements, you wrote the corrected coefficients to the eeprom. I am right in this matter? I am very interested in this topic, since I would like to calibrate mine too, but I am looking to find an easyer way, to read it out through GPIB (no good results yet, but I am still working on it), and avoid the disassembly of the RF deck, and unsolder the eeprom. Probably the $R and $W GPIB commands, as I figured out, will help doing this I would really appreciate your help. Thanks, Gyorgy |
| jjoonathan:
I disconnected the digitizer IF input coming from the frequency converters and instead applied a constant tone from a signal generator. Then I used GPIB to read the measured amplitude at 10,000 points or something -- effectively this gave me the calibration trace. It used linear interpolation, so the high resolution trace clearly indicated both the frequencies and amplitudes of the correction table (inflection points). Now that I had the correction table, I created a script to try all "origin/offset/encoding" triples and look for strong correlation. I didn't find anything on the CF card, so I looked harder for EEPROMs and eventually found the EEPROM on the RF deck. The search script found (IIRC) 8 hits corresponding to 8 settings of the input attenuator. With luck, you might be able to use the EEPROM dumps in my dropbox to locate EEPROM in the memory map with $R and then use $W to update the calibration values. Please let us know how it goes! :-+ |
| chick0n:
--- Quote from: chick0n on November 01, 2022, 06:37:19 pm ---I think the culprit is in the 2nd Mixer Stage. When I Power the whole RF-Block with the Voltage Filter (11.5Volt), EXCEPT for the Blue Cable over the 91Ohm Resistor (Where I inject 12.5V). The Analyzer shows me the -10dBm Cal Signal as -21dBm (Uncalibrated). This is the same, as if I Power the whole block with 12.5V. With this, I can get the Analyzer to Self Calibrate... This is the BIAS voltage for the "E5" IC (I think this is a Minicircuits ERA-5 MMIC. Is it?) The Problem is, the ERA-5 Datasheet says, it needs about 5V BIAS Voltage. So with 11 to 12V over the 91Ohm Resistor, it should be about 5V at Pin3 of ERA-5. BUT I measure between 9.7 to 10.4 Volts at Pin3. So ERA-5 is toast? The resistor measures OK. --- End quote --- I replaced the ERA-5. (BIAS Voltage of 4.8V seems perfect) And its working now. Frequency Response from 10MHz to 3.5GHz is very good now. Over 3.5GHz its a bit over the place, maybe because the YTF Calibration is wrong, but seems solvable with a little tweaking. Also the the Step Attenuator was replaced, so the Frequency Correction is wrong. But for the Price I got the analyzer for, im pretty pleased. Another little problem is the BIAS Voltage for the first mixer Diode (See Picture). When I connect it, the input Signal degrades. Disconnected everything seems fine. I have 2 RF-Decks with this same problem here, and I heard from others who have this problem. The Diode marked "D2V", seems to be a HSMP-3802 double PIN Diode, where just one Diode is used. It measures OK in the component tester. Mixer Diode seems OK too. |
| chick0n:
I made Firmware with all software options, for R3267/73. You need hardware option 01, to use the software options. Just delete the old files from your cf card, and copy the new ones. Dont format your CF-Card with Windows!! Should work for R3273, R3267 with CF-Card and maybe R3264. Im still looking for Firmwares higher than I08. Im especially looking for firmware from analyzer with "OPT.05 Audio Demodulation Output Option", to check if this is hardware or software option. Maybe some Options are useful for Hobby use.. Especially with the AMPS Option, you can measure FM-Deviation and SINAD. Options: --- Code: --- OPT61: IS-95 [A08] Aug 08 2001 OPT62: 3GPP [J02] Nov 08 2004 OPT63: GSM/DECT [D01] Jul 08 2003 OPT64: PDC/PHS/IS-136 [B04] Jul 25 2000 OPT65: cdma2000 [D00] Jan 24 2003 OPT66: Bluetooth [C02] Jul 08 2003 OPT67: HDR [E00] Jun 28 2004 OPT69: HDR(MS)[B00] Jun 28 2004 OPT73: AMPS/JTACS/NTACS [A05] Aug 08 2001 --- End code --- |
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