eHam Forums => HomeBrew => Topic started by: DC9OE on March 04, 2019, 12:08:01 PM

Title: Charly 25 a homebrew TRX based on Red Pitaya
Post by: DC9OE on March 04, 2019, 12:08:01 PM
Hi Guy's, I am new  to this forum, my call sign is DC9OE, name is Edwin, however I am not new to the subject (licensed in 1969... guess my age... hi).

Would just like to present our little homebrew project here, especially as we will be at the Dayton Hamvention again this year on the DARC booth.
Some people might remenber us, we have been presenting our prototype TRX based on Red Pitaya last year already, however a lot of progress has been made to ensure other people could use our components as well.

Originally this was started as a local club project, in the meantime it has become much bigger - so what is it:

- we use Red Pitaya / Stemlab as the basis for our TRX so what we have build is a SDR TRX
- additional HW has been developed around Stemlab, this is a CODEC board, supporting low latency CW and including a dual 7W Audio Amplifier
- a multi functional board including a 20W PA, 2 Channel RX Pre-Amplifier and Attenuator, a SW controlled automatic Predistortion Attenuator, a Antenna Coupler with Predistortion output and lots of other features
- in addition we have designed 11 Band Preselector Filters (17 poles) which provide a non distorted  listening experience

More info on the project can be found here (in english) :

If folks in this forum are interested I can provide much more information.
Needles to say, we have also adopted the Power SDR Software to support our Hardware.

People who like to talk and discuss with us can find us at the DARC booth this year in Daytion.

Vy 73 de Edwin, DC9OE

PS. for those of you who want to understand what type of filter we have build, here is a liitle beta test program to calculate High End RX Filters