An update on RF Explorer WSUB3G

After many months of hard work, we got a candidate design for final production of the new wideband model covering 15 to 2700MHz, labeled as WSUB3G.

It will be available as an Expansion Module RFEMWSUB3G, so you can plug it in any RF Explorer base unit, and will be available from SeeedStudio and distributors.


Can you plug a RFEMWSUB3G module on any base unit model? Yes. Some combinations may make more sense than others, but functionality will be available in whatever combination you need it to be used. So can you plug a RFEMWSUB3G into a 433M model? Sure. And what about a 2.4G base unit? You bet. So there is a natural upgrade path no matter which RF Explorer version you are using today or planning to use tomorrow.

Is there any reason why there won’t be a WSUB3G base unit alone? The reason is extra RAM and FLASH needed for the wideband module, the base unit alone has not enough resources to drive it.


RF Explorer 3G Combo will be the highest end model, well suited for the Pro TV/Media/Audio user with a WSUB1G base unit and a RFEMWSUB3G expansion module already assembled. This is convenient as the WSUB1G model exhibits slightly better sensitivity and sweep speed in the UHF range of major interest of this business area. In this way you can order and use a WSUB1G device today and expand it later with RFEMWSUB3G, or order it as a RF Explorer 3G in one single order, whatever is better for your needs. Price will be the same one way or another.


Retail price for RFEMWSUB3G expansion module will be $140.

Full RF Explorer 3G combo units will be available for $269. A simple math shows this being the same as a $129 WSUB1G base unit together with a $140 RFEMWSUB3G.

Offering such a wide band device at this price tag is a real challenge for all the involved parts on the chain, and we will do an extra effort to have a launch offer you can adhere to the first two weeks for an attractive discount.

Preliminary specification

  • Frequency band: 15 - 2700 MHz
  • Frequency span: 112 KHz – 100 MHz
  • Amplitude resolution: 0.5dBm
  • Dynamic range: -110dBm to -10dBm
  • Absolute Max input power: +30dBm
  • Average noise level (typical): -105dBm
  • Frequency stability and accuracy (typical): +-10ppm
  • Amplitude stability and accuracy (typical): +-3dBm
  • Frequency resolution: 1Khz
  • Resolution bandwidth (RBW): automatic 2.6Khz to 600Khz

On the down side, as you can see the Average Noise Level is about 10dBm worse than WSUB1G, and the dynamic range is also a bit shorter than WSUB1G. This is due to the wide bandwidth internal balun and mixer conversion loss, a design factor you cannot overrule except by adding extra LNA and filters which will quickly increase the cost. Nevertheless, this is still comparable or better than commercial spectrum analyzers in the range of $2000+ and certainly orders of magnitude better than USB-key products designed to work with computers only. This is also better than the 2.4G model in the 2.4GHz band.

On the plus side, the Resolution Bandwidth is as good as the WSUB1G model and that is outstanding, you need to pay $5000+ or more to get any equivalent performance in the market. You can resolve signals as narrow as 2.6Khz in the whole band.

In addition to that, this new model comes fully protected for RF entry power up to +30dBm (1W) which is plenty to carry it over pretty much any place with no risk of damage due to reasonably strong radiated fields. In comparison, the WSUB1G model is protected up to +5dBm only so you typically need external limiter to play safe with strong fields.

Power consumption is a bit higher than other RF Explorer models due to the extra components, but should still run for 10hs+ or more on a single battery load.

Some beta users have been testing it for some time already; actually BloomingtonFPV shared a video with WSUB3G in action already (Thanks Tom!) with an early firmware version you can see here. Results are in line with expectations.

Production estimate

While the hardest design steps are already complete, the production and testing phase is just starting. A lot of specific test design steps are required for this module to be fully tested before assembly to guarantee quality in the whole band. As we are incorporating new components from manufacturers we didn’t work with in the past, we expect to learn about component tolerances, delivery time and stock as we go. All that adds uncertainty so we cannot reliably plan for a specific date. Our target is to start offering RFEMWSUB3G at some point in May, but this is not written on stone, we will keep you updated as we learn more.


We are currently on v1.09 Beta 03 and will probably be in Beta 05 at the time this product is available for ordering. Make sure you order it only if you are ok with upgrading firmware as it progresses.

The Windows PC client is still on the works but will come out with some extra features for all models.

Detailed model map

See below a general model map to easily identify the actual scope of WSUB3G when compared to earlier offering (click on the image for a larger view).