I removed the OCXO option 004 (10 MHz) from an 8591A to install it on an 8593E. The spectrum are working fine but the software (Show Option) of the 8581A still think that the option 004 is install. How to program the 8591A that there is no option 004 anymore and the 8593E that it is equipped with the option 004 for now on?
The first thing that you need to realize is that most all of the 8590 series instrument options identify themselves at instrument power-up, they are not programmed into the instrument, and option 004 is one of them. It identifies itself by one of the wires in the harness running to it being pulled to ground.
What you will have noticed is that the two instruments use different wire harnesses and connectors for this option, so you will have had to modify them in order to plug them into the other instrument. (5 pin single row connector on the 8591A, and 6 pin two row connector on the 8593E)
One other thing that you may not be aware of, and this is probably what is causing your problem, is that if the 8591A does not have option 004 it will not have anything plugged into the reference wire harness connector on the A25 Counterlock board assembly (J3), while the E series will need to have the seperate reference board attached. This is because the 8591A A25 board has the standard 10 MHz reference built onto it, while the E series does not, it needs a reference board.
My guess is that when you took the option 004 OCXO from the 8591A and somehow attached it to the 8593E A25 board, you also took the standard reference from the 8593E and somehow attached it to the 8591A A25 board.
To correct this for the 8591A all you will need to do is remove the standard reference board and wire harness from J3 of the A25 board, and take the reference out coax cable that was originally connected to the option 004 OCXO and connect it to J7 on the A25 board, as this is the standard 10 MHz refernce output. This should make it all work right and the on-screen identification of the option will be gone.
For the 8593E what you need to do is make sure that the wire harness on the A25 J3 end has pins 3 and 5 connected together (they should not already being going anywhere else). Pin 3 on the board is ground and pin 5 has the sense line connected to it with a pullup resistor to +5V. When you ground it by connecting it to pin 3 it will identify the option.
Wow! Thank you. Yes, I did modify the harnest on both instrument.
I did a quick try by just removing the wire that was connected on pin 3 and 5 on the 8591A. The Show Option does not show option 004 anymore and the "Oven Cold" message it not shown. Could this modif will be enough for the 8591A? Tomorrow, I will connect pin 3 and 5 on the 8593E.
Just removing the one wire on the 8591A would work, but probably not as well as possible. This is because the 10 MHz reference that you are now using cannot be adjusted, and unlike the OCXO it most likely needs it.
If you were to try running the adjustment for the 10 MHz reference, which unlike the OXCO reference is done through the CAL menu and is not a manual adjustment, the 8591A it will only adjust the one on the A25 board, which you are not currently using, it doesn't know anything about the adjustable reference on the other little board.
If you just pull the wire harness and move the coax to the A25 J7 connector, which is very close to the little reference board, you will be done...