SDR First Look

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The future is here. Maybe that is not quite right. Software Defined Radio (SDR) has been around probably long enough to drink legally in all 50 states. But then I have never seen a radio take a drink, ever.

It's a FlexRadio Systems, “FLEX-1500” SDR which is the baby of their product line. It is a 5 watt output QRP transceiver that (must) uses a personal computer as its basis of operation. I won't get into the theory of SDR here but suffice to say they are equally important system partnership.

My out-of-the-future radio has arrived on my ham desk. Actually half of it has been there for many years. The radio part seems futuristic to me so I will leave it at that. It is a ham transceiver that has only one control on the case, the on/off push button. Everything else is a hardwire I/O (In/Out) connector of many variations except for the ground post which I hope doesn't need to be an I/O.

The only indicator on the case is a blue LED in the middle of the On/Off push button. It's one of those blinding light laser beam like devices that I don't like to look straight into. I am sure it is NOT dangerous but most of us know how penetrating a blue LED appears. No issue, just a comment. I think it looks cool.

I have one on my electric tooth brush that I use as a night light at 3:00 AM in the morning.

The Computers

I have connected the FLEX-1500 to two of my personal computers.

The most powerful is my office computer. It's a home assembled unit built by myself and has been rebuilt once after it suffered heavy damage in a home lightning strike. As did everything electronic in my home office including all my ham radio gear.

Currently this computer (I call “Office”) has a 64 bit quad AMD processor running at 3.5 MHZ, a decent independent (non motherboard) PCI video card and 8 Gigabytes of RAM. The OS is Windows 7. I don't consider exact hardware detailed specs important here. Let me just say it can carry any load quite well. With SDR it is running 5% to 10% CPU load.

The second computer (rover) I tried is my little low powered ASUS Eee PC1005HAB Netbook 1.6 MHz Atom 270 processor (32 bit), single core but 2 logical (hyperthreading) I upped system to 2 GB RAM, OS was WIN 7 Starter. I just upgraded to free to WIN 10 OS so will test again with new OS.

My Linux (sandbox) could not be used as there is no software from FlexRadio Systems for Linux. (I'd vote for that!)

The Software

PowerSDR v2.7.2 is the current software for the FLEX-1500. It will run as either 32 bit or 64 bit as it contains drivers for both. FlexRadio Systems has other (and newer) software for its larger SDR systems but they are not compatible with the FLEX-1500 and its USB computer interface. (The others use Firewire).

I am sure Firewire was chosen because of its increased speed which looked good at the time of design. I have Firewire I/O on my “Office” computer and used it for my old video camera, but it is seldom available on laptops these days. USB3 is now most favored… Just a personal comment about the other FLEX SDR systems)

The spec for the Flex-1500 is USB1.2 and it seems adequate for the purpose. I would think USB 2 or even 3 would be a logical upgrade. I have read comments about the “slow” USB1 interface with the FLEX-1500 but I haven't experienced any yet. (It IS just out of the box…)

The issue I think is there are a lot of reasons communications to the FLEX-1500 over USB1 may be slow in any particular case and that (now) slow standard is an easy target. I suspect there are many other contributing issues. I will be looking…

I had terrible problems loading the software on my “Office” computer. It starts to load, the green “progress” bar moves fully to the right, and it says, “Standby while the system is configured.” That standby never ends. It would stall out there, lock up the computer and never finish. I spent probably 16 hours installing and trouble shooting the software install on “Office”.

The install on ROVER went perfectly. No issues at all. Thankfully I had a good install I could reference to trouble shoot the “Office” install. It ended up that I found .bat (batch) files that were not executing in in rather obscure directories in “Office” Even the “skins” needed a batch file run to configure. I had to rename the batch files to “.cmd” files so they would manually execute at my command (then name them back). There is obviously a software issue in my WIN7 Ultimate OS that killed the .bat files from executing. Some day I may go figure why, but PowerSDR v.272 is installed and running fine now.

First Impression

The FLEX-1500 is a REAL radio. WOW! Superior weak signal reception. The displays are a spoiler to going back to my TenTec Omni VII but I can compensate. The OMNI is a great radio…

I am going to have to spend a lot of time with all the settings and variations of those settings. But honestly, the FLEX setup is NOTHING compared to setting up my MACH3 CNC machining control software.

The bands were all down with very little activity. I messed with CW and my keyer and found no problems (yet) of latency issues with running the built in keyer at 20 wpm. I can't stand full break-in (and have never needed it) so maybe that is the issue. In any case I will be investigating that in much more detail. No contacts made on CW yet.

I heard a very weak special event station N9Q on 20 meters sideband (14.267 Mhz). I could hear him and see light traces in the waterfall but no bumps in the panadapter display. He was calling CQ but no activity. I picked up the mike, cranked the transmit up to 100% (5 watts) and gave him a call. He heard me the second attempt and called my back with my correct call sign. He even called my by my name as he looked me up in QRZ. He was also named Dan and located in Elkhart, Indiana. N9Q is still being received in the pictures above. I worked him yesterday.

Not bad for 5 watts sideband and an R7 vertical antenna at my end.