Red Pitaya Stand Alone – „DiscoRedTRX“ von Wolfgang (DH1AKF)

Red Pitaya Stand Alone – „DiscoRedTRX“

More than a year ago I found in the WWW articles about the „Red Pitaya“. http://www.redpitaya.com

And there is a russian developer, Pavel Demin (located in Belgium, Catholic University Louvain), who wrote a lot of software for the Red Pitaya, especially for use as software defined radio. His programs are open source.  pavel-demin.github.io/red-pitaya-notes/

As I was a C programmer in my business years, I thought about the association with a microcontroller and a touchscreen, and found the STM32F7Disco as good in price and usable.

I contacted Pavel Demin, and he agreed to develop together a standalone solution, he named it „DiscoRedTRX“.

My part was the STM side, and he wrote the Red Pitaya part.

Now I am proud to present a working solution, look at the next pictures:

The main menu shows all other elements. In the upper middle you can display the result of a frequency sweep. In the future there will appear a spectrum diagram around the tuned frequency.

The tuning menu let you enter any frequency number, or you use the up- and down buttons to step through the frequencies. By holding these buttons, you start the scan function. Each frequency step occurs immediately in your headphone.

The VFO button leads you to the tuning wheels. The upper wheel has 1, the middle 10 and the lower 100 times of the stepwidth (resolution), you can selekt on the left side. There is a „flywheel“ algorithm programmed, to manage bigger frequency steps. With the black quadrats the turning of the wheels is animated.

And a special function is: touch the middle or lower wheel leads to a smooth frequency,

e.g. 7002345 -> 7002300    or   3663897 -> 3663900  (result: rounded values)

In the meantime I found a critical tester, Jacinto (CU2ED). He is very satisfied with this solution…

The Band/ Memory selection menu:

Here you can see my testing platform and the next model in foreground  (in develop).

Old version and new enclosure:

The new enclosure with Touchscreen (STM32F7Disco), Step attenuator, Red Pitaya and 10W PA (2 x  RD16HHF1)

This shall be my stand alone version.

To reach higher output, I constructed with assistance of Roland, DK4RC and Andreas, DL5CN a little PA.  The PCB is from China (ebay).

330W PA with BLF368 (30 Volts)  – 2 fat output transformers, each 1:4 (TLT)

left the input transformer, outer right: the 1:1 Balun

73 Wolfgang (DH1AKF)