HP8922M Use as network analyzer and other purposes

[SaabFAN]

I am thinking about buying a HP 8922H->M (that's what is printed above the monitor), which I want to use as a generic spectrum analyzer, as well as a network analyzer and Signal-Generator.

Partially to measure the components of the Spectrum Analyzer I'm building myself, and also because it seem that it can be used as a signal-generator with an easy to use interface, which would save me the trouble of building such a thing myself, which I already tried until I realized how massive that undertaking would be

Does anyone know if I can use this device for these purposes?

What also puzzles me a bit is the fact that there's only very little information available about this thing in Forums...

[TAMHAN]

Hello,
to me, it looks like this is a GSM test set dedicated to GSM signal analysis.

All I found was this: http://www.upc.edu/sct/documents_equipament/d_176_id-449.pdf


The unit you are looking for, probably, is the 4195A...

[razberik]

I dont think it shall work as an spectrum analyzer. I got 8923B for few coins few years ago. It has a lot of nice HW inside it, but it is useless.
I simply didnt find any SW capability which is at least little similar to spectrum analysis. Nothing.

[SaabFAN]

I just skimmed over the first few pages of the User-Guide.

It seems to me that the instrument would be capable of doing what I want it to do (except doing automated Network-Analyzing stuff).
There's a CW Mode where the user can specify either a GSM-Channel or the frequency as well as the amplitude directly.
There's also a Peak Power Detector available, an audio-oscilloscope and measurement capabilities for audio signals, including THD and noise.
And there's a Spectrum Analyzer.

The only catch I can see, so far at least, is the fact that the whole RF-Section only operates from 10MHz to 1000MHz, so anything between DC and 10MHz has to be up-/down-converted with an external circuit.

I'm currently looking through the performance specifications to compare them to a HP8591.

[SaabFAN]

Okay, I think I just found a massive flaw: The Spectrum Analyzer has a minimum Span of 5kHz (basically every SA I have seen so far can go down to 0Hz) and a maximum of 10MHz (and that's with uncalibrated Overrange)! With a normal spectrum Analyzer you can select a frequency span that ranges from 0Hz right up to the maximum possible frequency (1.8GHz for example).
So that's a big shortcoming...

The RF Signal-Generator and the remaining Parts are more promising though. But using this beast as as Network Analyzer seems to be out of the question now...

EDIT: It might be possible to use the internal BASIC Interpreter of the device to emulate wider spans by switching the center-frequency in regular intervals, but it seems that the Spectrum Analyzer is really taylored towards checking the output of a GSM transmitter inside the channel-space and not much else.
The RF Generator, Audio analyzer and RF Analyzer (Power-Meter, phase measurements, etc.), as well as the demodulation features (I've found a german website where someone described how he used one of these devices to listen to FM-Radio) are still interesting though.

[TheSteve]

An 8920, 8921, 8924, E6381A or E6380A would all likely be better options for you. Of course they generally cost more and you need to ensure they have the options you require installed.

[nctnico]

I have the feeling that HPAK made instruments dedicated for radio communication instead of bolting analysis onto a generic spectrum analyser (like Advantest and Anritsu seem to do). I don't see why HPAK did that because the instruments aren't compact or light. The HP8922 series aren't boat anchors, they are boat sinkers!

[SaabFAN]

I can see why they did this: Test the entire GSM-Station with the 8922 when it leaves the factory, but to check the performance of the individual components, you have to buy the other devices manufactured by HP (Spectrum Analyzer, RF-Generators, Audio-Analyzers, etc.). Potentially generates more sales that way.
Or the customer grabs a bunch of instruments and controls them via GPIB to perform the same stuff.

For digital TV they developed an Option for the 8594 though.

The 8922H with the M-Upgrade, which is currently on sale on ebay and which I am at least a little bit tempted to buy, is, as far as my research goes at least, something we in Germany would call a "Eier legende Woll-Milch-Sau" (Egg laying Wool and Milk producing Pig). It can do everything, but nothing really good. Someone who could comment on this from first hand experience would be great though to see if there's something these monsters can do really good (except testing GSM Stations obviously).

Btw. I like these boat-anchors. They are built much more robust, if you do something stupid, the chances of repairing them is much higher than with newer stuff and the UI is mostly better.
And there is that certain "something" of a green CRT-Screen

[wine+dine]

You got it quite right that it does a lot but the generic functions are not terribly good.
It does give you a 10M-1G signal generator, the spectrum analyzer option goes from 10M-1G but max. 10 MHz span at a time.  It does have peak-find cursors and peak-hold display option.
There is a "digital scope" but up to 50 kHz only - intended to look at the demodulation output.
Screen prints work directly to a serial HP printer like an old Deskjet 500 series.
The built-in BASIC programmable controller can be used to control external GPIB instruments IIRC, but you need a serial terminal or emulator to talk to it, and one of the special memory cards to save programs.
If you get one real cheap you may want to consider it but be careful because of the weight, i.e. shipping costs.

[SaabFAN]

There's one on ebay for about 350€ with 6 months of Warranty that shows signals to be about 1dB too high, so it needs calibration.
It is sitting there for about half a year now (started at 450€ back in march) - That's why I'm asking.

Shipping would be 50€ btw.

I haven't looked at this further, but if the BASIC Controller isn't able to chain several Spectrum-Scans together to give a full spectrum from 10MHz to 1GHz, and instead is only able to control external equipment, it's basically useless for my purposes.

EDIT: Okay, I just checked the manual again. The BASIC Controller works like a GPIB-Controller that controls the Internals of the machine. Chaining commands like Setting the RF-Generator Frequency and amplitude, tuning the RF-Analyzer, read the Peak Value and print value to the serial Console could theoretically transform the 8922 into a Network Analyzer with the help of a PC to display the results.

But there are better devices on ebay to do that for less money.

If the BASIC-Controller could display the result on the CRT, that would be a different case, but I haven't found anything that indicates that this is possible