| Electronics > Repair |
| Advantest R3273 / R3267 Repair |
| << < (13/13) |
| Gyorgy Albert:
3g57, chick0n, Could you take as much possibe high resolution pictures of the TG module pcb-s while you are working on it? I have multiple R3267 and R3273 units (it is one of my obsessions), but none of them has the tracking generator. I am thinking about making one myself (it is not something impossible at all). The key is, if I/we can decipher the paralel bus connection and communication to the main circuit board. Since I do not have one unit with TG, I cannot do this, but maybe if you will help (and maybe other forum members too), it can be done. What I conclued from your pictures: On the control board the U20, is probably a Lattice CPLD used for paralel BUS to serial conversion. The U4, U6, U21, U22 are the bus transceivers and glue logic between the bus and the Lattice chip. The U7 (25C16) should be the EEPROM for the calibration coefficients. To get its exact content will be very important. It is an SPI EEPROM, the interface (the Lattice CPLD) between the SPI and paralel BUS of the M68K system is made similarly as in the case of the RF module. In one of my units, which has option 21, I noticed that the preicsion OCXO is installed in a similar enclosure as the TG module (obviously, it is missing the upper RF part). But it seems, that the bottom control board should be similarly. The programming of the AD9850 can be made probably using the same SPI serial interface. I will disassembly the option 21 module, maybe I will be lucky, and it has a complete control board (maybe almost identical with the TG control board). This also means, that the TG and the option 21 cannot be used in the same time. BR, Gyorgy |
| chick0n:
I made a copy of the TG Module EEPROM. Yes...every Module in the R3273 has the Lattice Chip, and a CAL EEPROM. |
| 3g57:
Albert! I'll try to do this during his preventive maintenance. |
| 3g57:
--- Quote from: chick0n on January 07, 2025, 02:58:03 pm ---yes..position of R32,R40 --- End quote --- R32,R40 I will take measurements without dismantling from the middle terminal to the left and right without changing the polarity of the probe. |
| chick0n:
--- Quote from: Gyorgy Albert on January 07, 2025, 04:04:44 pm ---3g57, chick0n, Could you take as much possibe high resolution pictures of the TG module pcb-s while you are working on it? I have multiple R3267 and R3273 units (it is one of my obsessions), but none of them has the tracking generator. I am thinking about making one myself (it is not something impossible at all). The key is, if I/we can decipher the paralel bus connection and communication to the main circuit board. Since I do not have one unit with TG, I cannot do this, but maybe if you will help (and maybe other forum members too), it can be done. What I conclued from your pictures: On the control board the U20, is probably a Lattice CPLD used for paralel BUS to serial conversion. The U4, U6, U21, U22 are the bus transceivers and glue logic between the bus and the Lattice chip. The U7 (25C16) should be the EEPROM for the calibration coefficients. To get its exact content will be very important. It is an SPI EEPROM, the interface (the Lattice CPLD) between the SPI and paralel BUS of the M68K system is made similarly as in the case of the RF module. In one of my units, which has option 21, I noticed that the preicsion OCXO is installed in a similar enclosure as the TG module (obviously, it is missing the upper RF part). But it seems, that the bottom control board should be similarly. The programming of the AD9850 can be made probably using the same SPI serial interface. I will disassembly the option 21 module, maybe I will be lucky, and it has a complete control board (maybe almost identical with the TG control board). This also means, that the TG and the option 21 cannot be used in the same time. BR, Gyorgy --- End quote --- Your Option 21 looks strange. Looks Interesting. I think your Picture shows Option 25 "Reference Converter". With this, you can have 3 different Reference Input Frequencies (10 MHz, 15 MHz, 19.6608 MHz) As the Datasheet mentions you cant have OPT74 TG and OPT25 at the same time, this would make sense. I have a OPT21 OCXO, but its bolted on the underside of the RF Deck. About TG Module. PLL Board. it contains a VARIL "VCO690-4300T" VCO (4.2GHz - 4.4GHz). A LMX2306 PLL. A AD9850 DDS Synthesizer. And a MC12093 Prescaler. If I remember correctly, the 4GHz from the VCO gets prescaled by "Voodoo Magic :)" to 550MHz range for the PLL IC (I think, the white 5 Pin component with the Red dot, close to R218 does this). The 200MHz Reference Frequency, gets prescaled by 4, wents into the DDS IC and the Output of the DDS wents into the LMX2306 OSC Input. The TG Module contains 3 PCBs. I call them "Adapter Board": Contains the Lattice Chip and CAL EEPROM. "PLL Board" Contains VCO, PLL,DDS. "Mixer Board": Contains Mixer, Input / Output MMICs, Filters, RF Diodes. |
| Navigation |
| Message Index |
| Previous page |