| Electronics > Repair |
| Gigatronics 6100 Repair |
| << < (3/4) > >> |
| Nitrousoxide:
--- Quote from: Berni on February 21, 2019, 05:00:34 pm ---There are no error codes mentioned in there. But there is a troubleshooting section, tho by the looks of it the instrument is very different from a 6100 so questionable if its of any use. I also included the block diagram in case yours is similar as it may aid in understanding how it works. --- End quote --- Yeah, does seem quite different from a glance. Thank you so much anyway, ill give it a read. I really didnt want to blindly start replacing components, but that's what I might have to do (beginning with all the poly/tant caps). My theory is that there must be an active loop filter on the board somewhere and some ESR from dried up capacitors is causing issues. I just don't have the time to reverse engineer the circuit, so shotgun approach seems best sadly. Just an addition: No expense was spared when this thing was put together. The coax cable looming, even just for bias/supply voltages is insane! There's even a gigatronics labeled can that only has two SMA connectors on it, connected to it by rigid coax is... itself. There is a passive part that literally connects to itself and nothing else... Seems like they didnt need it and just omitted it by not connecting it... absolutely crazy. |
| Berni:
Yeah they are quite impressive units. I got a Gigatronics 6100 that goes to 8GHz and a Gigatronics 7100 that goes to 20GHz. Id imagine the front panel also looked pretty striking back in the day. Just that green 2x10 character LED matrix display must have cost a pretty penny back in the day.(I think the 6100 has a 1x10 instead) First thing id check are power supply rails with a scope. Also check what happens to the output in the area where the PLL goes unlocked. Does the output disappear, does it wander off in frequency or amplitude, does it become jittery or noisy etc. Perhaps you can work your way from the output connector backwards to trace where the same issue appears. Hope you have a spectrum analyzer cause it will likely come in useful. |
| Nitrousoxide:
Must admit, The LED display does look VERY nice. With the gear I have, I think I can cove 9khz-2.7Ghz and 4-6Ghz. I suppose thats good enough to detect a signal. Right now, just sweeping the device over its output range yeilds nothing. Absolutely no output, even in the ~5Ghz range where both lock and level lights are illuminated. I will check the power supplies first and then if that brings me to a dead end, ill draw up my own block diagram. The issue is, I can only really make an assumption as to what the supply rails should be as, again, no documentation :( |
| Berni:
Well my 6100 did at one point develop a fault where it gave very little output power no matter how high you cranked up the level. This turned out to be a fault in the switched attenuator block before the output. One of the solenoids inside got stuck and kept the biggest attenuator in circuit. I found that shimming the faulty selonoid with some paper helped, might just be mechanical wear. Later on i scored a replacement attenuator module, but i haven't put it in since it might throw off the calibration. Good luck with yours. |
| Hg7wgs:
This is a gigatronics 7100. What pcb-card might it be missing? Where can I find a schematics diagram or servicemanual? Maybe i build the pcb. Thx Szabolcs |
| Navigation |
| Message Index |
| Next page |
| Previous page |