The HP/Agilent 8753 series are a range of vector network analyzers (VNAs) made by HP/Agilent that are very popular. Despite all of the 8753 series are discontinued and most are beyond support by Keysight, the 8753 is still an extremely popular VNA, mainly among commercial companies, but some are owned by radio amateurs or other hobbyists, as 8753 prices have fallen dramatically from their new cost. We don't know how many HP or Agilent 8753s were sold, but we find that around 30% of the customers of Kirkby Microwave SMA and N calibration kits are using 8753 series VNAs. All the HP 8753 series instruments can be used with the Kirkby Microwave coaxial calibration kits.
This page has a number of sections, which will hopefully give you all the information you ever wanted about 8753s.
These instruments have a number of hardware and/or software options. Some options such as rack mount handles, extra manuals etc are not that important when buying a used instrument, as but others are. The main options are:
If you have an 8753A, then it is only possible to add the time domain option (010). But on the 8753B, 8753C, 8753D, 8753E, 8753ES and 8753ET, it is possible to add options 002 (harmonic analysis), 006 (6 GHz) and 010 (time domain). Do not waste your time copying EEPROMs, as there's a much easier and safer way. Just email firstname.lastname@example.org, with the serial number of your instrument, and what options you require. He will email you back some codes, which will unlock the options. You will need to search your service manual of your instrument to find out how to use the codes. On an 8753ES the procedure was:
Be aware that whilst option 006 (6 GHz) will work without any hardware changes on the 8753B and 8753C, this option requires a new source assembly and recalibration on an 8753D, 8753E, 8753ES or 8753ET. It is probably not economically viable to add option 006 to a 3 GHz 8753D, 8753E, 8753ES, or 8753ET.
Adding software option 002 (harmonic analysis) or 010 (time domain), do not require calibration on any 8753 series instrument.
There are a large number of differences between the different models, although all can be used with our calibration kits. Some of the key differences are listed in the following table. If anyone finds any errors, or can add any comments, please contact us and we will correct it. The system dynamic range figures only relate to the A and B receiver inputs, not the R receiver input, which has a much lower dynamic range than the A and B inputs. Some instruments have slightly different specifications over some frequency ranges due to spurs or other odd reasons. Please check the manuals for full details.
|Feature||8753A||8753B||8753C||8753D||8753D (option 011)||8753E||8753E (option 011)||8753ES||8753ES (option 011)||8753ET|
|A photo||8753C||8753D option 011||8753E||8753E option 011||option 011option 014||8753ES option 011||8753ET|
|Display||Mono CRT||Mono CRT||Color CRT||Color CRT||Color CRT||Color LCD||Color LCD||Color LCD||Color LCD||Color LCD|
|Lower frequency limit (without option 006)||300 kHz||300 kHz||300 kHz||300 kHz||300 kHz||30 kHz||300 kHz||30 kHz||300 kHz||300 kHz|
|Lower frequency limit (with option 006)||N/A||300 kHz||300 kHz||30 kHz||30 kHz||30 kHz||300 kHz||30 kHz||300 kHz||300 kHz|
|Upper frequency limit (without option 006)||3 GHz||3 GHz||3 GHz||3 GHz||3 GHz||3 GHz||3 GHz||3 GHz||3 GHz||3 GHz|
|Upper frequency limit (with option 006)||N/A||6 GHz||6 GHz||6 GHz||6 GHz||6 GHz||6 GHz||6 GHz||6 GHz||6 GHz|
|Is option 006 just software?||N/A||Yes||Yes||No||No||No||No||No||No||No|
|Integrated S-parameter test set||No||No||No||Yes||No||Yes||No||Yes||No||No|
|Integrated T/R test set||No||No||No||No||No||No||No||No||No||Yes|
|Floppy disk drive||No||No||No||Yes||Yes||Yes||Yes||Yes||Yes||Yes|
|Time domain measurements (Option 010)||Yes||Yes||Yes||Yes||Yes||Yes||Yes||Yes||Yes||Yes|
|Harmonic measurements (Option 002)||No||Yes||Yes||Yes||Yes||Yes||Yes||Yes||Yes||Yes|
|Precision frequency reference (Option 1D5)||No||No||No||Yes||Yes||Yes||Yes||Yes||Yes||Yes|
|Maximum measurement points||801||1601||1601||1601||1601||1601||1601||1601||1601||1601|
|Frequency offset mode (for mixers)||No||Yes||Yes||Yes||Yes||Yes||Yes||Yes||Yes||Yes|
|System dynamic range (30 kHz-50 kHz)||N/A||N/A||N/A||90 dB||100 dB||?||?|
|System dynamic range (50 kHz-300 kHz)||N/A||N/A||N/A||100 dB||100 dB||?|
|System dynamic range (300 kHz-16 MHz)||100 dB||100 dB||100 dB||100 dB||110 dB||?||100 dB|
|System dynamic range (16 MHz -1.3 GHz)||100 dB||100 dB||100 dB||110 dB||110 dB||?||110 dB|
|System dynamic range (1.3 GHz-3 GHz)||100 dB||100 dB||100 dB||110 dB||110 dB||?||110 dB|
|System dynamic range (3 GHz-6 GHz)||N/A||80 dB||95 dB||105 dB||105 dB||?||105 dB|
|Real time clock||No||No||No||Yes||Yes||Yes||Yes||Yes||Yes||Yes|
|User defined preset||No||No||No||Yes||Yes||Yes||Yes||Yes||Yes||Yes|
An 8753 when switched on will default to one of the internal calibration kits - probably the 85031 7mm (APC7) calibration kit. If you are not going to use that kit, then you must load the coefficients for the kit. Lots of people fail to do this, and get poor results because of it, although they don't often known this, as they don't know how to check the results properly. The complexity of the process of loading the correct calibration kit coefficients depends on whether the kit is built into the firmware of the VNA or not. If built into the firmware it is very easy. If not built into the firmware, it is not hard to do, but is easier on the more recent models (8753D, 8753E, 8753ES and 8753ET) as these have floppy disks drives, whereas the old 8753A, 8753B and 8753C do not.
This is the easiest option, but a typical 8753 had about 6-12 kits in its firmware. HP, Agilent and Keysight have produced considerably more kits than this, so even using kits from HP, Agilent or Keysight, you will often find the kit is not in the firmware. We have in fact needed to load the coefficients for both the Agilent 85054B (type-N) and 85050B (APC7) kits we process, as neither are in the firmware of our 8753ES with the latest (7.74) firmware.
The coefficients for that inbuilt kit are loaded. You are ready to perform the calibration, as described in section 5 below.
There are a number of other ways to load the calibration kit coefficients into an 8753. Kirkby Microwave have a page that details how to set up and use calibration kits on an 8753
There are many forms of calibration an 8753 supports, but the most commonly used, and most accurate are: