DISCLAIMER: I have no association with UVB-76 station, neither do I have any clue what is the content I am relaying. I can only assure, that the signal is received on 4.625MHz AM-modulated 900km NW from supposed origin and retransmitted unaltered. In no way can I guarantee this service, nor be considered responsible of any content re-transmitted. The only purpose for this relay to exist is because lot of people who do not have equipment or are located too far from station seem to be interested about listening to it. Should the UVB-76 station- or transmission content owners feel violated in any way, please contact me at uvb76.repeater@gmail.com and we will work it out.

Note, that because of shortwave radio signal propagation specifics the station can be more or less reliably received from around 4pm to 6am GMT on summertime. It is almost 24h audible during the winter, with short "skip-zone" blank-out around 6pm GMT.

The USB feed is considered as main source of audio today, as the voice messages are much better audible there than on the AM stream. However, the buzzer sound from the AM stream is somewhat more pleasant to listen at, so both feeds are kept simultaneously.

Friday, July 1, 2011

SDR MK1 Firmware V1.1 Released

The SDR MK1 Firmware V1.1 is released and can be downloaded from http://sdr-mk1.googlecode.com/
The source code is also available for downloading should anyone be interested of what is really happening inside.

I am strongly recommending for everybody to go through upgrading procedure as indicated in googlecode page, as the update will make quite a difference!

The major difference is in dynamic range, what was crippled with original (0.7b) firmware. Instead of the original 40dB, the radio has now, depending on working mode, the dynamic range from 82dB to 110dB with noise floors on -100dB and -70dB respecivly (measured with pure s1.9MHz sine wave feed into RF input).

The second channel is now also working with 12kHz bandwidth, but more importantly, the second channel can now be used for the noise canceling, i.e. the radio now has true diversity mode!

As finding the dynamic range bug took about a month worth of head-banging, the ExtIO DLL work has been delayed, but I am now able to get back to it!