Affordable Handheld Spectrum Analyzer “Sniffer”

I’ve had my TinySA Ultra Plus for a while now and am finding it useful as a general EMI “sniffer” for radiated emissions troubleshooting, especially on large equipment or subassemblies where the noise source may be buried within the system. I still like my AIM-TTi PSA6005 (10 MHz to 6 GHz) handheld analyzer for more accurate field measurements ($3,250), but for an inexpensive “quick and dirty” measurement, the TinySA Ultra fills the bill nicely.

The base specs for the ZS406: Spectrum Analyzer for 0.1-900MHz or, with Ultra mode enabled up to 5.3 GHz, and level calibrated up to 6GHz. You can actually observe signals up to 12 GHz. There is also an RF signal generator with sine wave output between 0.1-900MHz or square wave up to 4.4 GHz. Caution, overdriving the input beyond +10 dBm can destroy the front-end input switch. See below for a protective device. Although users have successfully replaced the surface mount switch, I’d just treat the analyzer respectfully and avoid the issue. Don’t use this around high-power transmitters!

In order to duplicate this, order the Tiny from an approved dealer, as there are many underperforming clones. Visit https://www.tinysa.org/wiki/ for lists of approved vendors. There are now three models of TinySA Ultra, with the two newer “Plus” models and I’d probably choose the ZS406 or ZS407. In the U.S., the preferred dealer seems to be R and L Electronics. The TinySA Ultra Plus (ZS406) is listed there at $160. I purchased my original on Amazon from SeeSii Electronics (an approved vendor) for $250 in 2023 (it’s now listed at $170).

For protection, it’s recommended to install a Mini-Circuits VLM-33W-2W-S+ SMA limiter onto the RF input port ($65). Since many near field probes use a male SMB connector, I purchased a set of SMA to SMB adapters from Amazon ($8.40). They’re brass-plated, not gold, ha ha!

Now, plugging in the near field probe results in a handy spectrum sniffer for locating those nasty emissions. Long time readers know I prefer the longer and thinner Beehive Electronics near field probe kit for general EMC troubleshooting. In the example above, I’m using the larger Beehive model 100C H-field probe and measuring the radiated emissions from a six-port charging station and looking from 100 kHz to 200 MHz. Beehive sells a set of four near field probes for $325. I plan to take this with me on a client job next week, so there may be more to report in actual field use.

I wrote a more detailed review of this analyzer here.