The following are procedure of 3GHz expansion.
Please modify by a self-responsibility.
HP8752C network analyzer has 3GHz ability basically. There is no difference in hardware between 1.3GHz and 3GHz.

 1) Prepare X28C64P-15 class EEPROM.
 2) Carefully remove original EEPROM from CPU board by de-soldering.
 3) Solder the reliable 28 pin IC-socket to the place of original EEPROM.
 4) Carefully read out the original EEPROM contents by ROM writer, and then save the data for backup. Keeps original EEPROM.
 5) Write the read out data to new EEPROM, and then insert to 28pin IC socket on CPU board.
 6) Return the CPU board to 8752C and turns on the power, and then confirm the original function.
 7) Turn off the power and then remove the CPU board and then remove the EEPROM.
 8) Edit the first 3 byte to "F9" on read out data, and then write to EEPROM. (Write the same data to all 3 bytes)
   (In 8752C case, option flags are existing top 3 byte of EEPROM.)
 9) Insert the EEPROM to CPU board and then change the A9 CC jumper to "ALT" position, and then return the CPU board to 8752C.
10) Turn on the power, and then confirm the startup message indicate opt.003 opt.010.
11) Execute "RF Output Power Correction Constants" (Test #47). About the detail, refer to the service manual.
   (This test requires the power meter (HP346A,347A or 348A) and power sensor (HP8482A etc.) and GPIB cable.)
12) Execute "Frequency Response Correction Constants" (Test #57 then #53). About the detail, refer to the service manual.
   (This test requires the calibration kit (Ex. 85032B Type-N) and NP-NP reference RF cable.)
13) Power off and then turns on the power again. and then confirm 3GHz functions. 
14) Power off and remove CPU board. and then return the A9 CC jumper to "NORM" position, and then return the CPU board to 8752C.
15) By the work of above, 3GHz modification would be completed. If before it was worked at 1.3GHz, it does not need the other test items basically.
16) If needed, execute the verification test to refer the service manual.

When added the 70dB attenuator (Opt.004), may need the following test items. (I did not execute the attenuator addition.)

 1) Source Default Correction Constants (Test #44)
 2) Source Pretune Default Correction Constants (Test #45)
 3) Analog Bus Correction Constants (Test #46)
 4) RF Output Power Correction Constants (Test #47) 
 5) Source Pretune Correction Constants (Test #48)
 6) RF Output Power Correction Constants (Test #47) again.
 7) Frequency Response Correction Constants (Test #57 then #53)

mmbfj310