VOA Radiogram for the weekend of 31 August and 1 September 2013 included a Base64-encoded image of a VOA logo. Base64 is a means of including an image within the html code of a web page instead of referring the browser to the URL of an image elsewhere on the server. The latter is not an option on shortwave.

The problem is that Base64 requires many characters to produce even a small image, and given the speed of most of the digital text modes used on VOA Radiogram, it would be very time consuming.

This past weekend, we wanted to test the RSID, the brief signal at the beginning of a digital transmission that automatically changes the mode on the listener’s decoding software, for both MFSK64 and MFSK128. MFSK128, at 480 words per minute, is fast enough to make the transmission of a Base64-encoded image somewhat practical.

At that speed, however, the MFSK128 has a rather high failure rate on shortwave. It would be amazing if any of these MFSK128 Base64 logos survived, but some did.

Each of the following was 31 August 2013, 1600-1630 UTC, on 17860 kHz.

First, Guy, KC5GOI, in Texas:

Michael in Germany:

Roger in Germany:

The rather small VOA logo required all of the code below, which even in the 480-word-per-minute MFSK128 mode takes more than three minutes to transmit:

On the other hand, the SVG-formatted VOA logo below, created by UK listener Mark Hirst, only required fifteen seconds to transmit: