When you're shopping for oscilloscopes signal spectrum analyzers, the first decision isn't which brand to choose; it's whether you need a working instrument today or you're ready to spend time on a repair project. The FNIRSI DPOS350P and the Aeroflex IFR Marconi 2390 / AN930A both sit below $300 but are aimed at different kinds of buyers.
Quick verdict
The FNIRSI DPOS350P is the low-risk choice: a 4-in-1 instrument that covers waveform display, signal generation, and spectrum analysis. The Aeroflex IFR Marconi 2390 / AN930A is the repair-oriented choice: an analyzer that powers up but doesn't pass its own tests because of a configuration error. If you need measurements this week, pick the FNIRSI. If you can fix a controller configuration, the Aeroflex deserves a second look.
Comparison table
| Feature | FNIRSI DPOS350P | Aeroflex IFR Marconi 2390/AN930A |
|---|---|---|
| Price | USD 225.00 | USD 299.95 |
| Price bar | ||
| Condition | New - Open box | For parts or not working |
| Primary function | 4-in-1 oscilloscope, signal generator, spectrum analyzer | 22 GHz spectrum analyzer with tracking generator |
| Display | 7-inch, 1024×600 pixels | Powers up with a good display |
Where each product wins
The FNIRSI DPOS350P wins when you want a working all-in-one instrument for immediate signal analysis. It gives you a built-in screen and multiple measurement modes with no repair work between you and your first waveform.
The Aeroflex IFR Marconi 2390 / AN930A wins when you're comfortable troubleshooting a controller configuration issue and you're looking for an analyzer project with more RF range than a typical bench scope.
Product notes
FNIRSI 4IN1 Digital Oscilloscope DPOS350P 350MHz 2CH Signal Generator Spectrum Analyzer
The FNIRSI DPOS350P is the easy pick when you want to connect a probe and start measuring. Its 4-in-1 design covers a scope, signal generator, and spectrum analyzer, and the 7-inch 1024×600 screen gives you a clear look at waveforms. A 1ns rise time and 1GSa/s real-time sampling help capture fast signals, while two digital channels let you compare two inputs at once. The condition is New - Open box, so the unit has been opened and inspected rather than sealed in factory packaging. The main limitation is the open-box status itself: you're buying an inspected unit, not a pristine sealed product, which means a little more uncertainty about handling. For buyers who want a working all-in-one scope with a screen and two channels, this is the straightforward option.
Aeroflex IFR Marconi 2390 / AN930A 22Ghz Spectrum Analyzer TRK GEN PARTS ONLY
The Aeroflex IFR Marconi 2390 / AN930A is not a purchase for someone in a hurry. This is a 22 GHz analyzer with a tracking generator factory option, and the unit powers up and boots, but the configuration EEPROM wasn't moved when the controller was replaced, so it fails its internal testing and is being sold for parts or not working. If you have the ability to replace the EEPROM and reconfigure the controller, you could bring this back to a functioning state. The limitation is clear: as sold, it's a parts unit, not a working analyzer. Buy it only if the repair path is something you've done before.
Final choice by use case
Choose the FNIRSI DPOS350P if you need a working bench instrument this week. At $225.00, it gives you a built-in screen and the convenience of an all-in-one tool at a price below the Aeroflex. Choose the Aeroflex IFR Marconi 2390 / AN930A if you're comfortable with electronics repair and you see the $299.95 price as the entry point to a repairable analyzer rather than the cost of a working instrument. The $74.95 spread between them is the difference between a ready-to-run tool and a project with real upside.
