My HP 83640A is working fine (frequency, level, sweep) from 2.4GHz up to 40 GHz, but the Low Band from 10MHz up to 2.4GHz has an issue on the frequency. On this band, the frequency is exactly 100 MHz below the frequency displayed.
For example, with a CW displayed of 1GHz, the actual frequency produced is 900MHz. This 100 MHz negative shift is exactly respected on the Low Band. The level is fine.
Not found any relevant information on the Service Manual nor in the Troubleshooting Manual.
And impossible to locate the CLIPs for this generator.
I would be very interested is somebody could give me some help.
Thanks in advance.
Thanks for your answer.
The 100MHz 0dBm coming from A7 reference is good and arrives well at the input of the bloc A24 Low Band. So the frequency synthesis is fine ... but the Low Band A24 seems to have problem.
Is it possible to open this block and check the elements inside ?
Is there somewhere any documents related to this Low Band element ?
Thanks for your help.
And, when the generator is working, if I program a CW between 10MHz and 2.3 GHz, I get the message "Unlock (HET Unlock)".
Here I am today, I will continue exploring the manuals, but it's not easy without the schematics. I would be very interested to have information on what is there inside the A24 Low Band module (5086-7463), and as well to get the schematic of the A20 Interface board. Actually, the Troubleshooting Manual focus onto these two elements as a possible faulty elements.
I would be interested to know what means "HTE", and in which board (or module) is located the faulty PLL. I didn't found this in the manuals.
Any information will be really welcome. Thanks a lot for your help.