An update on RF Explorer WSUB3G
Ariel Rocholl
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.
Pricing
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.
Firmware
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.
Any question, let me know anytime.
Cheers. Ariel
Martin
Paul Morris
Ariel Rocholl
A Mac version for the Firmware update tool is on the plans, as well as one for Linux. I do not have an ETA for it yet, but I am sensitive on how important is for many of you.
In the meantime you can use either Parallel in your Mac or grab a Windows PC for this specific step.
Best regards,
Ariel Rocholl
Ariel Rocholl
To help a bit on the many users who are waiting to get one, I can offer some boards from my lab. I have two spare at the moment and can have another 2 or 3 by next week. These boards have been fully tested and calibrated, can be delivered worldwide for $90 but don't include antenna or CNC top cover, so I would suggest only to interested users who already have an expansion daughter board and gets the WSUB3G as a replacement. In this way, the CNC top cover and antenna from the installed board can be reused.
If you are interested, send me an email to rfexplorer (at) arocholl.com with subject "WSUB3G Beta board", I will serve them in a first-in, first-out basis.
Ariel Rocholl
Thanks
Ariel Rocholl
There is a small HW difference between Beta and final boards, and it is a DC blocking capacitor the beta board doesn’t have. In the Beta boards, the power limiter diode is directly connected to the SMA port, whereas in the final board there is an extra 220pF capacitor. Other than that, your board has 100% the same components than the final HW. There are also some minor variations in the PCB, needed for mass automatic assembly process when compared to the manual process I used for the beta boards.
From performance perspective there is no difference at all, except if you expect to deal with your beta WSUB3G directly into a signal in a circuit where there is DC component, in that case you should use a DC block adapter or a specific cable with DC block.
All the final beta boards are delivered calibrated, with an advanced process we put in place in the product line. However, beta boards were not delivered calibrated. You should see an improvement in accuracy, particularly with DSP=Filter mode, when the board is calibrated, so you are suggested to calibrate it using the firmware v1.09 if you have access to a reliable signal source.
Thanks Ken Camuccio for pointing out the differences between Beta and Final boards were not properly documented.
Paul Morris
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Ariel Rocholl
There are no Beta boards left, all units with and without discount are final.
Thanks for checking,
Ariel