SSB firmware patch for Si4735-D60 on
There is a number of complaints on the Internet about the performance of Si4735 in shortwave receivers, where it is used to demodulate SSB. For example:
The specific problem seems to be the AGC curves, both amplitude and timing.
I will describe my experience with Tecsun PL-880.
1. The initial gain is too high, resulting in the noise being amplified to the maximum amplitude even when there is no signal.
2. The attack time is not fast enough. Combined with the first problem, this results in strong distortion to the point of clipping in the beginning of each word.
3. The decay/hang is too fast.
Tecsun/Kaito support is not responsive regarding this issue. SiLabs AN332 document states that the encrypted firmware patches (such as used to demodulate SSB) are not written by the customer (Tecsun). This is why I am posting the complaint here.
Oct 28 2017, 3:08 PM