| Electronics > Repair |
| Aeroflex IFR-2398 / calibration / repair help |
| << < (15/16) > >> |
| George Edmonds:
H Reoly #54 in this posting. G Edmondsi |
| EB4CUV:
Hi George, Sorry for the inconvenience. In that post #54 the attached .pdf is from the rceiver front-end board and I don't see any other archive. The schematic that I need is of the input board where the N connector is and not for the front-end because the diodes are burned. Thanks, Julio |
| George Edmonds:
Hi Julio Having now had a little time to look at your photograph I would be very surprised if this is the only damage. At present I cannot provide a schematic of the input assembly, but you do not need one, just a little information. The only RF path components are C1, DC blocking capacitor which is a 1uf at 25V device and the two catcher diodes CR1 and CR2, these diodes are MSMP-3892, data sheet attached. All the rest of the input assembly is providing a plus and minus reference supply derived from the main instruments + and – 15VDC supply. CR3 and CR4 are MMBZ5232LT1 Zener diodes. Regrettably I suspect that there will be further downstream damage, particularly to the solid state switches. Hope this helps G Edmonds G6HIG |
| EB4CUV:
Hi George, Thanks for your help George. People like you make life easier for others. I've removed the bad diodes from the input board, leaving just the capacitor until a replacement arrives. Your suspicions are true. The first solid state switch on the front end board is damaged. I have done what vk2cow said in post #56, remove the first AH002R2 switch and bridge pins 1 and 7. Now, I inject a 40Mhz and -30db input signal into the N connector and the device passes all the tests correctly. I'm on the right track. By injecting other signals, the device measures almost correctly. The next step is to do a good calibration. The next question is: where can I find the calibration software or some other that can handle the device? Again, thank you very much for your time and help. I hope my experience is useful to others as well. Julio, EB4CUV |
| Ron Castle:
Hi George, Ours is working but the center of the screen is all washed out. I guess I can use the video out would you know what the display P# might be. |
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