I checked out the other less expensive USB items but they were limited in the range of frequencies they could cover. So I contacted them and this is their reply.
http://rover.ebay.com/rover/1/711-5...0001&campid=5336136228&icep_item=272136012635
New message from: rfinstrumentshouston
The SA0314 will go down to 200Khz with an elevated noise floor of -65dbm.
the normal range is 2Mhz to 3.3 Ghz and is a limitation of the hardware.
http://rover.ebay.com/rover/1/711-5...0001&campid=5336136228&icep_item=272136012635
New message from: rfinstrumentshouston
The SA0314 will go down to 200Khz with an elevated noise floor of -65dbm.
the normal range is 2Mhz to 3.3 Ghz and is a limitation of the hardware.