Digital Modem from BG5ROJ: A new SDR transceiver add-on board soon!

UPDATE 2018.05.13 – FYI, I no longer support the BG5ROJ modem. Please, contact the manufacturer directly. Thanks for your understanding.

I received direct information today from the «Ham operators group from China BG5ROJ» about a new product that will be release soon.


As a beta tester for this group of genius guys, I will personally be able to try a new add-on board that will add a «complete» SDR transceiver functionality inside the Digital Modem! This will let the modem to be a complete QRP transceiver solution by itself.

As you probably seen in my previous videos and posts, an antenna port will be easily added within the removed cap on the right side of the modem. The add-on board will be connected inside the digital modem within the 2 onboard connectors already found on the modem board. So, the digital modem was already initially designed to host many other futur features by their designers.

The transceiver will have these specification:

Frequency range: 5MHZ ~ 50MHZ (No 80m and 160m band)
Working Modes: CW, USB/LSB, FM
RF Power Output: around 1W
Freq Stability: 7 ppm (Si570 Grade C)
Receive Current: 250 ma
Transmit Current: 1.5A
SDR Architecture: Quadrature Sampling Decoder (QSD)
Sensitivity*:  MDS = -130 dBm
Mic Type: Internal MIC
Size (W x H x D): 59.6 x 85 x 10mm 

Here is the TRX add-on board that will give the full SDR capability to the digital modem.


Here is now the add-on board installed inside the digital modem… very neat installation!



The SDR transceiver display when the SDR function will be turned on in the menu. Actual display is on 20m band.


A look at a tight integration of the standard transceiver functions on the small display: S Meter, mode display, VFO, etc.


So, this little nice Digital Modem will soon be a complete SDR QRP transceiver. They did not told me what will be the retail price or even when it will be available to order. But, compared to the price of the Digital Modem itself, it will not be too expensive.

For sure, I will receive a unit to test first as a beta tester for the group. So you will able to see on my Youtube channel how it works.

Stay tuned guys, more information soon!

Please, do not forget to subscribe to my blog. You will be informed as soon as I post new documents! If you have questions related to my blog, feel free to ask me questions!:-)


Jeff | VA2SS