Direct Sampling Front End Board
Over on this Japanese language blog, ttrftech has been experimenting on a type of direct sampling front end board (Use Google Translate) for a direct sampled RTL-SDR dongle. More info about his direct sampling front end can be found on this post. Translated, it appears his board has the following feautres.
- Filter x2 up to fifth order
- RF switch
- Amplifier
- Power regulator
- Input transformer (optional)
- The RJ-45 (optional) or the SMA input connector
- Power supply to the antenna
- Output to U-FL or SMA (ipex) connector
The results seem to show his board does improve reception. Note that the RJ-45 appears to be the antenna. There also appears to be review of the board by “pup” here and a video showing the board filtering out a broadcast FM image in the video below. On Pups blog there are also more posts about the board under this tag.
![Direct Sampling Front End](https://www.rtl-sdr.com/wp-content/uploads/2014/05/directsamplingfrontendboard.jpg)
Thank you for introducing my frontend board here and apologize for inconvenience that this blog was written only in Japanese.
As another solution for receiving HF with RTL dongle, I have developped a budget frequency converter board and have distributed a few hundreds of the parts kit in Japan. Please refer the following link with google translate.
http://ttrftech.tumblr.com/kit/hfconv
Thank you.