I just ordered a 3561A. Repairing vintage HP units is such a joy. So much a person can learn from these. It is a kind of activity / hobby that should not be pursued for the profits. I really suggest you take a look at 3335a.
Nice one Simon. I've had to work on boards too, without and extender boards and have done what you've done with the ribbon cables. In a pinch I've soldered wires or coaxes to the boards and installed the board with the test points hanging out. Also I've removed the pots and solder wires to them to extend them outside of the unit. Some units it's not to bad to do it that way but if you have quite a few adjustments or test points it can be a real pain in the butt. Look fwd to your next video on this nice Analyzer. Good job Simon. Best Wishes n Blessings. Keith Noneya
I'm a german chemist and probably don't even understand a tenth of what you are talking about But I find your videos mesmerizing to watch, especially your radio restorations.
Glad you never gave up. I did replace the crt with an lcd screen. Much light unit now. Super easy and makes you feel like you have a more modern full color analyzer.
+rb I think I will have to do the same. The crt is very weak now. Problem is I have to inport the screen from the USA which means an additional £100 charge.
Do you have any more details of the extender connection you used? I've got 3563A which has an input offset problem (0.4V) which is causing some problems when used as part of an automated measuring setup!
I just ordered a 3561A. Repairing vintage HP units is such a joy. So much a person can learn from these. It is a kind of activity / hobby that should not be pursued for the profits. I really suggest you take a look at 3335a.
Nice one Simon. I've had to work on boards too, without and extender boards and have done what you've done with the ribbon cables. In a pinch I've soldered wires or coaxes to the boards and installed the board with the test points hanging out. Also I've removed the pots and solder wires to them to extend them outside of the unit. Some units it's not to bad to do it that way but if you have quite a few adjustments or test points it can be a real pain in the butt. Look fwd to your next video on this nice Analyzer. Good job Simon. Best Wishes n Blessings. Keith Noneya
I'm a german chemist and probably don't even understand a tenth of what you are talking about But I find your videos mesmerizing to watch, especially your radio restorations.
+Felix Many thanks Felix. I do my best with my limited skills. I am happy you enjoy them.
Glad you never gave up. I did replace the crt with an lcd screen. Much light unit now. Super easy and makes you feel like you have a more modern full color analyzer.
+rb I think I will have to do the same. The crt is very weak now. Problem is I have to inport the screen from the USA which means an additional £100 charge.
looking good, well worth the effort and investment!
I use a toothbrush to clean the PCB, it is about the right stiffness to get rid of stubborn buildup, and doesn't scratch the PCB.
Yeah but it tastes of flux afterwards!
I would be looking closely at the op amp after the pot, purely on the fact the DC offset change between ranges.
Yes I am not entirely sure the negative amp sides opamps have an offset.
Do you have any more details of the extender connection you used? I've got 3563A which has an input offset problem (0.4V) which is causing some problems when used as part of an automated measuring setup!
I bought if from Ebay from a seller who was selling other extender boards. He was based in the states but so long ago I forget his name. Good luck,
Did the original relay have extra pins for an internal shield? Koto makes a lot of relays with shields between the coil and the contacts.
Yes as does the replacement. The missing pin is connected to the same point as the one on the opposite side. The old relay just had two.