The author operates J.R. Richardson Electronics, a contract engineering firm in Westminster, Md.
The first time I saw a USB device with an antenna connection, I said there was no way to have a complete spectrum analyzer on that device; when I saw what it would do, I was hooked.
When you look at the Broadcast Electronics Avatar Test Receiver, you get the same first impression. However, when you load the software, hook up an antenna and plug the USB cable into the computer, a new world opens up.
The Avatar allows you to analyze not only your signal but all the signals on the FM radio band. Here is the list:
- RF spectrum and waterfall displays of your signal;
- Multiplex spectrum display;
- Modulation power (how “loud” the station is);
- RDS — see all the transmitted information;
- Instantaneous deviation;
- Deviation history;
- Deviation histogram;
- Audio spectrum: L & R, plus peak and average;
- Stereo Lissajous display — see the relative phase and amplitude of the L&R;
- Stereo quality;
- Audio S/N (even without cutting modulation).
The Avatar’s ability to look at all of those parameters on a computer gives the technician the look-see at what is happening. Much of the work that we perform involves questions like “Am I over-modulating,” “Is someone interfering with the signal,” “What is my RDS sending out” and “Do I have good stereo separation?”
The RF spectrum shows where your signal is in the FM band, and your spectral occupancy. The MPX spectrum gives you a look at your L+R, L–R pilot, RDS and any SCAs you may have. Modulation power shows a relative indication of how loud you are and of course the RDS analysis shows what is being transmitted.
Something I really like is that the device looks for the stereo pilot and if it is not there, it shows the mono signal on the stereo quality signal.
Practical considerations
My Avatar is set up with an external antenna in my office, so that I can monitor several of the stations that I contract for. You have to be careful about multipath, which can cause apparent overmodulation to be displayed. For clean measurements, use the RF pickup tap on your transmitter.
I will be arranging a remote pickup site for my unit at one of my backup sites. I would consider two antennas, one omni and the other with a high-gain directional antenna on a rotor. I could then log in with a remote desktop connection and get a good reading.
The Avatar works well on a desktop computer or on my portable laptop in the truck. For this location, I have a whip antenna with a magnetic base, which would give you the same signal as if you were listening on the truck radio.
Using the Avatar for new installations, I’d suggest you do a screen grab and have a reference for future use. I have suggested the Avatar to a group that has a station in Key West, Fla., while their home office is in Valdosta, Ga. With remote access via PCAnywhere, LogMeIn or VNC they can monitor the station constantly .
The Avatar RF spectrum display shows the HD sidebands but does not decode them. Audio is analog. The unit also has an input for the AM frequency band, and can display the spectrum on that band, but the software currently does not support AM station analysis.
You are able to switch between 10 presets that you can program. You are also able to label the tabs with the call letters of the station.
The unit is very small and is powered by the USB cable, it fits easily in your toolbox.
Would I buy another Broadcast Electronics Avatar? At the price of $1,495 it is well worth it.
Radio World User Reports are testimonial articles intended to help readers understand why a colleague chose a particular product to solve a technical situation.
For information about this product, contact Frank Grundstein at 1-610-353-1970 or for Latin America sales Daniel Bizet at 1-217-592-4225 or visit http://www.bdcast.com.
