I had one of these for about a year. Still have went to turn it on the other day but it won't turn on checked the fuses are good. It displays for a split second and shuts off.
I bought a 8663A recently. Last owner said the problem is the line swtich but I check the switch itself and makes contact normally. At first, started and works well; but then never starts again. The panel glitches a bit when line switch is ON, but fan doesn't rotate and generator never starts. PSU issue, I think. Any idea of remarkable power supply problems in these machines? Hint: diodes all over PSU motherboard and inverter board are ok with DMM
Yes, switched mode PSUs can be real bears to debug. I had a bad case of that recently: ua-cam.com/video/VVrDyLMVS4U/v-deo.html . But this one should be documented and have a schematic, so that should be 10x easier. You just have to go through it stage by stage and see were you lose it.
@@CuriousMarc Many frustrating component swap and many hours later, I set aside the PSU issue for a while and I hooked the generator to four bench supplies to do performance tests. Now I have wrong freq between 144 to 159.9 MHz (96 to 106 in output, instead of displayed imgur.com/a/p76xnvh ) and oscillating attenuation between .9 to 1.8 GHz (here's a video of that: imgur.com/t57hI7G )
Looks like great progress to me, it’s mostly working! It’s pretty hard to do remote debugging. The first issue looks like something similar to me - a PLL that is out of capture range. Do you get an error when that happens that gives you a hint which PLL that is? The second one is wild! Looks like a giant suckout. Could it be a reflection somewhere in your setup, a bad cable or connector? Try to post on the EEVblog Forum or on the HP-Agilent at groups.io, you’ll get more eyes on the problem.
Coming back on problem 1, if it stays locked and you have no errors, you might have an issue in the digital counters inside the N loop or fractional-N loop.
@@CuriousMarc I do editing yesterday but it doesn't save, I don't know why haha YES, the second issue was solved changing a cheap connector, now the level is flat in all frequencies, you are very accurate! :D
I have the opportunity to get a partially working 8662 for less than $400, apparently has some attenuator and modulation issues, but the frequency synthesis and sweeper circuits are working fine. Is the attenuator in the 8662 mechanical, like in some HP spectrum anlyzers, and can fail due to mechanical problems? Or could this be a result of someone feeding too much reverse power into the signal output, which could have damaged the attenuator? Regarding the modulation section, do you happen to know of any pattern problems in there? Most of the documentation I could find was dealing with unlocking problems in the synthesis circuits, or PSU faults. All in all, would an 8662 be worth the $400 in this condition?
The attenuators are mostly mechanical, but there is also an ALC leveling circuit. Several good videos on The Signal Path on how to clean the attenuators.
I have two (2) 8660C's and I agree, awesome machines! ~Jack, VEG
I had one of these for about a year. Still have went to turn it on the other day but it won't turn on checked the fuses are good. It displays for a split second and shuts off.
I bought a 8663A recently. Last owner said the problem is the line swtich but I check the switch itself and makes contact normally. At first, started and works well; but then never starts again.
The panel glitches a bit when line switch is ON, but fan doesn't rotate and generator never starts.
PSU issue, I think. Any idea of remarkable power supply problems in these machines?
Hint: diodes all over PSU motherboard and inverter board are ok with DMM
Yes, switched mode PSUs can be real bears to debug. I had a bad case of that recently: ua-cam.com/video/VVrDyLMVS4U/v-deo.html . But this one should be documented and have a schematic, so that should be 10x easier. You just have to go through it stage by stage and see were you lose it.
@@CuriousMarc Many frustrating component swap and many hours later, I set aside the PSU issue for a while and I hooked the generator to four bench supplies to do performance tests. Now I have wrong freq between 144 to 159.9 MHz (96 to 106 in output, instead of displayed imgur.com/a/p76xnvh ) and oscillating attenuation between .9 to 1.8 GHz (here's a video of that: imgur.com/t57hI7G )
Looks like great progress to me, it’s mostly working! It’s pretty hard to do remote debugging. The first issue looks like something similar to me - a PLL that is out of capture range. Do you get an error when that happens that gives you a hint which PLL that is? The second one is wild! Looks like a giant suckout. Could it be a reflection somewhere in your setup, a bad cable or connector? Try to post on the EEVblog Forum or on the HP-Agilent at groups.io, you’ll get more eyes on the problem.
Coming back on problem 1, if it stays locked and you have no errors, you might have an issue in the digital counters inside the N loop or fractional-N loop.
@@CuriousMarc I do editing yesterday but it doesn't save, I don't know why haha YES, the second issue was solved changing a cheap connector, now the level is flat in all frequencies, you are very accurate! :D
I have the opportunity to get a partially working 8662 for less than $400, apparently has some attenuator and modulation issues, but the frequency synthesis and sweeper circuits are working fine. Is the attenuator in the 8662 mechanical, like in some HP spectrum anlyzers, and can fail due to mechanical problems? Or could this be a result of someone feeding too much reverse power into the signal output, which could have damaged the attenuator? Regarding the modulation section, do you happen to know of any pattern problems in there? Most of the documentation I could find was dealing with unlocking problems in the synthesis circuits, or PSU faults. All in all, would an 8662 be worth the $400 in this condition?
The attenuators are mostly mechanical, but there is also an ALC leveling circuit. Several good videos on The Signal Path on how to clean the attenuators.