WinRadio WR-1000i Slow Scan Spectrum Analyzer

MTM Scientific, Inc

ISA Card WinRadio Receiver

Figure 1: WinRadio WR-1000i ISA Card Receiver

The WR-1000i Radio is an ISA card for PC compatibles, capable of tuning from 500 kHZ to 1300 MHZ. The radio was manufactured by WINRADIO Associates, beginning in around 1995. We have used this receiver to construct a slow scan spectrum analyzer to sweep the entire range of radio reception. We sweep in the FM Wide, FM Narrow and AM bands from 100 MHZ to 1300 MHZ. A complete scan across all three modes requires about 36 minutes. The spectrums are plotted as overlays on a graphical output display.  

The slow scan spectrum analyzer was created by writing code in RBASIC. Information about this free software language for radio amateurs can be found at the website: RBASIC.COM  RBASIC is a plugin for the WinRadio software which provides an Integrated Develpment Enviroment (IDE). The language facilitates writing scripts in a language very similar to regular Basic, but which interfaces directly to the Windows operating system for graphical and text-based output. A scanner can be created with a very small amount of simple coding.
Section of annotated RBASIC Script

Figure 2: RBASIC Script Excerpt for Slow Scan Spectrum Analyzer

The RBASIC script for the spectrum analyzer is set to run as a continouos loop.  Traces are superimposed on previous traces. This allows for a nice averaging of the signal activity for general review and consideration.  A typical output graph, taken over about 24 hours is shown in Figure 3. The antenna used was a simple homemade indoor dipole, and was only an expedient for basic testing. The first band (100-200 MHZ) is the bottom layer, the second band (200-300 MHZ) is the layer directly above, and so forth. We see the FMN in yellow is dominant over time, followed by AM, and finally FMW.

Graphical Outpus of Slow Scan Analyzer Script

Figure 3: Graphical Output of RBASIC Spectrum Analyzer Script

We have found the spectrum analyzer makes a very convenient tool for determining the local RF enviroment. Our plan is to attach a wideband antenna to the receiver and run it in parallel with our aerial observation program. A recent improvement has been the addition of gridlines to facilitate frequency identification. We also now have full 500KHZ to 1300MHZ range. Here is a link to the RBASIC file: scanner5.rbp
Full Range Spectrum Analyzer Output

Figure 4: Spectrum Output with Grid Lines & Full Range (500KHZ - 1300MHZ)


Since this card uses an ISA slot it was necessary to implement hardware and software of the same general era. We chose to install the card in a Dell Optiplex GL+ 5166 computer operating with Windows 95.  We have several of these computers and find them very reliable. They are especially useful for interfacing to vintage laboratory equipment, such as data loggers, EPROM burners, and devices requiring a standard serial or parallel port. These computers also have an onboard network controller, which makes FTP file transfer fairly simple. Our computers are also equipped with a Floppy Drive and CD-ROM drive, which is very useful for using boot disks and installing ISO operating system on CD.
OptiPlex GL+ 5166
OptiPlex GL+ 5166
WinRadio in OptiPlex GL+ 5166

   Figure 5: OptiPlex GL+ 5166 with WinRadio Receiver in ISA Slot
Preparing the vintage computer for this project was not complicated. The traditional method to install Windows 95 is to start with a boot disk on floppy, such as this: WIN95 Boot Floppy. The boot floppy will recognize your CD-ROM drive and allow use of an install ISO, such as this: Windows 95 Installation ISO. Note that the product key will be required during installation, and it is provided on the splash page of the link. The ISO must be burnt to disk using an image burner. A convenient and simple tool for the purpose is this one: CD-ROM ISO Image Burner.

We actually used a Linux computer tool for burning the ISO, as it was convenient to our work area. Here is description of setting up an inexpensive Linux Computer using Zorin. (A Linux workstation can be very convenient for technical pursuits, especially if you are comfortable using a terminal interface.)

Installing Windows 95 is straight forward. The only comment would be that the network interface did not automatically become active. We found it was necessary to choose the TCP/ICP protocol in the internet connection setup window.  When building up a system from scratch we find it convenient to install an FTP transfer tool, such as this: Windows 95 FTP Transfer Client. (This is an archived copy of www.simple-ftp-client.com) Note: Web browsing using HTTPS and Windows 95 is generally not practical because of present-day standards and encryption protocols for information exchange.

Although FTP file transfer is simple to implement using Windows, FTP can also be accomplished using a DOS terminal interface. Terminal-based FTP is possible via 4 basic commands: FTP, PUT, GET, BYE. The FTP command starts the session, PUT places a file on the site, GET retrieves a file from the site, and BYE ends the session. A suite of DOS based tools, including an FTP application, is available for networked vintage computers here: MTCP by Mike Brutman